Shade 10 CALLISTO (Shade Professional)
From ShadeCamp
CALLISTO (Shade Professional)
CALLISTO for Shade is a highly-customizable rendering plug-in developed for professional rendering in Shade.
CALLISTO for Shade (hereafter described as CALLISTO in this manual) improves the expressive possibilities for users who create animations, design products, and make architectural presentations using Shade.
CALLISTO Overview
High-Speed Rendering
Featuring a selective ray tracing algorithm that uses Scan Line, Ray Tracing, and Distribution Ray Tracing as needed, this plug-in allows you to complete a high-quality rendering in a shorter time. It features highly flexible functions to reduce the rendering time, allowing you to cut unnecessary calculations for each light source, specify the depth of calculation for reflection and refraction separately, and set different qualities of Distribution Ray Tracing for each light source and material.
Micro Polygon Subdivision for Curved Surfaces
With the Micro polygon subdivision function, curved surfaces can be rendered perfectly smooth. Since the CALLISTO Renderer automatically determines the setting for the surface subdivision, the user can obtain rendered images with beautiful curved surfaces without having to repeat detailed settings. A function to manually set the subdivision type is also provided for when you want to trade off quality for speed.
High-Quality Anti-aliasing
The optimal anti-aliasing setting differs for highresolution still images, animations, and Web images. To support these various output forms, CALLISTO includes an anti-aliasing function that allows sampling as many as 41 points per pixel.
Since CALLISTO also features a way to control the quality of anti-aliasing for each individual object, you can carry out highly accurate anti-aliasing on tiny objects without sacrificing rendering speed for the entire scene.
Sophisticated Material Settings
Various functions that are not included in the Shade standard renderers are available, allowing you to use Displacement Mapping that generates bumpy curved surfaces, change the intensity of parameters depending on the angle between sight and normal lines, set different surface attributes for front and back sides, and so on.
Using the ability to merge, partially fuse, and switch materials, it is possible to create interesting, complex materials, such as those with varying refractive indexes.
Built-in Photon Mapping
With the CALLISTO Photon mapping, you can calculate not only the soft light reflected from a wall, but also the caustics effect in which light is focused through glass. This function also enables high-quality Path Tracing with Photon mapping.
A variety of sky lights, as well as the “Geometry light” that uses an object as an illuminator, are also supported by Global Illumination using Photon mapping.
Using CALLISTO
Open “tut_1.shd” from the “Documentation - Sample” tab in ShadeExplorer. We will use this scene to describe the basic settings needed for rendering with CALLISTO.
Rendering
Select CALLISTO from the Method pull-down menu in the Rendering Options.
CALLISTO renders curved surfaces smoothly
Improving Anti-aliasing Quality
Since CALLISTO anti-aliasing allows you to make a broader setting than the standard renderers, the antialiasing quality in the initial state is lower than that of the standard renderers.
Left: Adaptive Anti-aliasing with CALLISTO
Right: Anti-aliasing with Ray Tracing
Select 3×3 from the Anti-aliasing pull-down menu in the Rendering options for high-quality anti-aliasing.
Rendered image with Anti-aliasing set to 3×3
Note: For more information on anti-aliasing settings, refer to the CALLISTO Reference section.
Applying Varying Indexes of Refraction
CALLISTO interprets the refractive index of objects differently than the standard Shade renderers so it is important to understand those differences when modeling.
1. Open “tut_2.shd” from the “Documentation - Sample” tab in ShadeExplorer. This scene will have a significantly different rendering result if using CALLISTO over a standard Shade renderer.
2. The above image was rendered using one of Shade’s standard renderers. Due to the refraction of light at the water’s surface, the balls underwater appear to be a different size.
3. Now try rendering the scene using CALLISTO.
Because CALLISTO calculates the index of refraction taking into account the object normals (which face the air-water interface), the surface of the water is perfectly reflective, resulting in a mirror-like effect.
The standard Shade renderers automatically calculate the refractive index for transparent surfaces. When using ray tracing, every time the light passes through a surface the direction of the surface is interpreted alternately as Front, Back, Front, Back, etc. When light passes through the front of a surface the refractive index for that material is used, and when passing through the back of the surface the inverse of the refractive index is used.
CALLISTO always interprets the Front/Back of a surface by the direction the normals are facing. This means that the inverse of the refractive index will be used for the outside-facing back of a surface, giving a strange result when rendered.
To fix this problem we will modify the objects in the scene.
4. Select “Tank glass” in the Browser and choose Enter Modify Mode from the Modify tool.
5. Now select Show Normals from the Modify tool if the red normal lines are not already showing. The normals point in the Front-facing direction of the object’s surface.
6. In the Top view we can see that the outside surface of the glass has all its normals facing inwards. Click the Flip Face checkbox in the Browser to the right of the “Tank glass” part. You will notice the normal lines now face outwards from the tank. Now render the scene again using CALLISTO.
The scene renders as expected
Calculating Indirect Light with Photon Mapping
Using CALLISTO Photon mapping, we will describe how to calculate indirect light. Open “GITut.shd” from the “Documentation - Sample” tab in ShadeExplorer.
In this scene, a spotlight and spheres are located in a colored room. Let’s use this scene and make a calculation for the indirect light using Photon mapping.
1. Choose View > CALLISTO Information to display the CALLISTO Information window.
2. Setting the Photon Map light source Select the Spotlight just below the Root Part in the Browser.
With the Spotlight selected, choose the Shape tab in the CALLISTO Information window, and if necessary expand the Light information.
The Shape Tab in the CALLISTO Information Window
3. Adding Custom Attributes Click the Create custom attribute button to activate the custom light settings. In the Photon Mapping section, click the Use Photon Map checkbox to enable it.
Objects with CALLISTO custom attributes will have an identifier such as “CALLISTO Light” at the end of their name.
Note: The “:CALLISTO Light” identifier will be removed when the custom light attributes are deleted.
4. Adjusting the Rendering Settings for Photon Mapping
Now select the Rendering Options tab in the CALLISTO Information window, and expand the Photon Mapping section if necessary. Before making adjustments, click the Default button at the top of the tab to switch to the default remder settings.
Click the Use Photon Map checkbox to enable it. Now the Photon mapping is ready.
5. Rendering
Choose Rendering > Render All. When rendering all objects in the scene, the CALLISTO log is displayed in the Message window and two progress bars are displayed in the upper-left of the Image window.
The first progress bar shows that the default illuminance is being initialized, and the second one shows that Photon mapping is being calculated for the spotlight.
In this render, light from the spotlight calculated with Photon mapping is expressed, and the caustics effect from the Photon mapping is slightly visible under the leftmost glassy sphere.
You can see a hazy pattern on the wall, which will appear if insufficient photon precision.
6. Increasing the Photon Precision
In the Rendering Options tab in the CALLISTO Information window, under Photon Mapping, enter “10” for the Multiplier for the Number of Photons setting. Render the scene again.
This photon calculation will take longer because the number of photons has increased.
Most rendering artifacts related to photon mapping can be resolved by increasing the size of the photon multiplier.
7. Calculating Indirect Light
Let’s calculate the indirect light using photon mapping. Enter “3” for both the Max Diffuse Reflection Level of Photons and the Max Specular Reflection Level of Photons. Render the scene.
Calculating indirect light results in slightly longer render times. The rendered image is shown below. Color bleed is visible on the left and right sides of the middle wall, and a caustics effect, in which refracted light is focused on the floor, is visible underneath the left sphere.
8. Calculating the Indirect Light in Greater Detail
Make the following changes to the photon mapping settings:
Illuminance Filter Size: 40 (Relative off)
Illuminance Sample Width: 10 (Relative off)
Verify that the Relative checkboxes for the above settings are off.
These settings means that the photon map will be calculated with a precision of 10 mm and adapted using a 40 mm filter. With these settings, render again.
Since the resolution used to calculate the photon mapping has increased a hazy pattern has appeared due to a lack of photons.
9. Using a Resolution-consistent Photon Calculation
Set the Multiplier for the Number of Photons to 300 and render again.
There is still a subtle haze left in this situation, but this problem can be solved by changing the Illuminance filter size.
We will use the previous result of the Photon mapping calculation to save time, because we do not need to re-calculate the photons.
10. Reusing the Photon Map for a Final Render
In the Rendering Options, set Photon Map Calculation to Never, Illuminance Filter Size to 50, and render again.
With Photon map calculation set to Never, the rendering starts right away, without having to recalculate the photon map. This time, you can see a clear rendered image with no haze.
Once a photon map has been calculated it can be reused even after changing the camara angle or render size.
Calculating Caustics with Photon Mapping
Let’s use caustics. Open “GITut_caustics.shd” from the “Documentation - Sample” tab in ShadeExplorer.
In this scene, the custom attributes for light sources have already been specified.
1. Rendering with Photon Mapping
On the Rendering Options tab of the CALLISTO Information window, enable the Use Photon Map checkbox and render the scene.
Caustics is automatically calculated. The caustics effect can be seen in the red shadow below the glass filled with wine.
2. Increasing the Photon Mapping Precision
In the Rendering options, specify the following items and render again:
Multiplier for the Number of Photons: 50
Illuminance Filter Size: 10 (Relative off)
Illuminance Sampling Width: 5 (Relative off)
With these settings, a 10 mm wide filter, a 5 mm sampling width, and 50 x 10,000 photons (the default number of photons) will be used to calculate the photon map.
We can see in this render there is a haze over the table, while the caustics effect is not clearly shown.
3. Creating an Illuminance Object
Achieving a high-quality render using only the Number of Photons, Illuminance Filter Size and Illuminance Sample Width settings can require a very large amount of time. One solution is to calculate the caustics and other lighting effects separately. To do this, we will create a CALLISTO Illuminance object.
To create an Illuminance object, choose CALLISTO Illuminance from the Create tool and click and drag around the table top and wine glasses in the Front view.
There are actually two cuboid Illuminance objects contained inside the “CALLISTO-Illuminance:” part shown in the Browser: “Global:” and “Caustic:.”
In the Browser, move the “CALLISTO-Illuminance:” part and place it directly below the Spotlight. This causes the photons radiated from the Spotlight to use the illuminance.
Move or skew the illuminance objects in the Top, Front and Side views to cover both the table and glasses, if necessary, using the Move tool.
4. The Illuminance Settings
First, let’s specify the illuminance information for the “Global:” object. The illuminance settings are located on the Shape tab in the CALLISTO Information window, in the Illumination Information section. Select “Global:” in the Browser.
Enter these values for the Illuminance Information:
Filter size: 15 (Relative off)
Sample width: 5 (Relative off)
Next let’s specify the illuminance settings for the “Caustic:” object. We will use greater arithmetic precision than that for the “Global:” object.
Filter size: 4 (Relative off)
Sample width: 2 (Relative off)
5. Doing a Test Render
Do another test render with the above settings. Compared with the previous result this image shows sharper caustics. Dim streaks of light caused by the caustics are spread across the table.
6. Increase the Number of Photons Let’s make change the following Illuminance Information settings for the “Caustic:” object:
Filter size: 2 (Relative off)
Sample width: 1 (Relative off)
On the Rendering Options tab, set the Number of Photons to 300.
Try rendering again with these new settings. This Photon map calculation will require about 10 minutes for a computer with a 1GHz processor.
The caustics effect now renders beautifully.
7. Final Render Reusing the Photon Map
Once the calculation is finished, set the Photon Map Calculation in the Rendering Options tab to Never to skip the Photon mapping calculation. This allows you to render the image at a larger size, adjust the camera angle, and so on without needing to recalculate the photon map.
By enabling the Save Photons in Custom Attributes checkbox, you can save the scene file and open it later, or copy it to another computer, and perform only rendering again, without needing to recalculate the photon map.
Rendered image at a larger size, after a color correction was made in the Correction window
Path Tracing Using CALLISTO
Open “GITut_pathtrace.shd” from the “Documentation - Sample” tab in ShadeExplorer.
A rack and horse figurines are located in the same room as that used in the “GITut.shd” scene. To render this scene optimally, we will explain how to use a combination of photon mapping and Path Tracing.
The custom attributes required to calculate a photon map have already been specified for the spotlight in the scene.
1. Rendering with Photon mapping First, we will perform rendering using Photon mapping.
In the Rendering Options tab of the CALLISTO Information window, adjust the following settings for photon mapping:
Use Photon Map: On
Multiplier for the Number of Photons: 50
Max Diffuse Reflection Level of Photons: 3
Max Specular Reflection Level of Photons: 3
Photon Map Calculation: Always
Illuminance Filter Size: 0.03
Illuminance Sample Width: 0.25
On the walls of the room, a light effect caused by the indirect light is expressed, but fine, detailed objects such as the figurines and the pole supporting the shelf are not rendered very beautifully.
The week point of Photon mapping is that you should target the finest and most detailed object to make the setting.
2. Rendering with Path Tracing
To solve this problem, CALLISTO is provided with simple Path Tracing.
To understand the Path Tracing effect, turn off the Use photon map checkbox in the Photon mapping settings, set Ray tracing level to 1 in the Path tracing settings in the Rendering options tab, and then render.
The rendered image has severe noise.
3. Increasing the quality of Path Tracing
Change the settings for Path Tracing quality as shown below and render again.
Ray tracing level: 1
Number of rays: 8x8
Shading rate diffuse: 2 (default)
Filter diffuse: 8
Although the noise subsides and the indirect effect is smooth, the indirect light on the figurine under the shelf and the brightness of the light reflected on the ceiling is less sufficient, when compared with the previous result using Photon mapping.
In CALLISTO Path Tracing, the Ray tracing level is fixed at 1. Therefore, rendering using only Path Tracing cannot handle indirect light such as that which reaches the camera after reflecting three times.
4. Photon Map calculation for Path Tracing Combining CALLISTO Path Tracing and Photon mapping allows speedy calculation for the complicated indirect light.
First, reset the Ray tracing level of Path Tracing to 0, specify the following items for Photon mapping, and render:
Use photon map: ON
Number of photon multiplier: 1
Max diffuse reflection level of photons: 5
Max specular reflection level of photons: 5
Photon map calculation: Always
Illuminance filter size: 0.05 (Relative)
Illuminance sample width: 0.5 (Relative)
To calculate complex indirect light, we used a larger value for the number of the photon reflections.
However, the calculation will be finished in a shorter time because Number of photon multiplier is small and Illuminance sample width is large. The quality of the image rendered with only Photon mapping is extremely low.
5. Path Tracing referencing Photon mapping
With the result of this Photon mapping calculation, perform rendering using Path Tracing. Choose Never from the Photon map calculation pull-down menu, specify the Path Tracing settings as shown below, and render:
Ray tracing level: 1
Number of rays: 8x8
Shading rate diffuse: 2 (default)
Filter diffuse: 8
The surfaces of the horse figurines, which are difficult to re-create using Photon mapping, are now beautifully rendered in great detail.
6. Making the final adjustment
There is still some noise left, so we change the quality of Path Tracing to make the noise unnoticeable.
The Path Tracing precision is improved by increasing the Number of rays value or decreasing the Shading rate diffuse value, while the time required for the rendering will be longer.
If you increase Filter diffuse, the noise will be reduced. However, the precision of the rendering calculation will be decreased, because the calculated result is blurred. Using an extremely large filter also decreases reproducibility of tone.
Choose Never from the Photon map calculation pulldown menu and specify the Path Tracing settings as shown below:
Ray tracing level: 1
Number of rays: 8x8
Shading rate diffuse: 1
Filter diffuse: 8
In the rendered result, the indirect lighting is good, and fine detail is achieved.
CALLISTO Reference
Rendering Options Dialog
The basic rendering settings for CALLISTO can be made in the Shade Rendering Options dialog. Each checkbox has almost the same meaning as for the standard renderers, while some parameters are slightly different. These must be understood to perform efficient rendering with CALLISTO.
Rendering Method
To perform rendering with CALLISTO, choose CALLISTO as the Rendering method in the Shade Rendering Options dialog.
CALLISTO is provided with Distribution Ray Tracing functions, including blurring of shadows and reflected images, and processes the Distribution Ray Tracing automatically and internally for necessary area. Thus, you are not required to change the rendering method manually.
Anti-aliasing
You can specify the quality of anti-aliasing using the oversampling setting and Ray tracing quality under the Misc tab.
Oversampling of Anti-aliasing
The oversampling value, the sampling level, and the actual view of sampling are shown in the table below.
The gray box indicates one pixel when rendering, while the red points indicate sampling point. In the actual rendering, the area exceeding the RGBA threshold value in the Anti-aliasing section of the Rendering options tab of the CALLISTO Information window is sampled. Thus, the area shown in the table below is not always sampled, and only the necessary area is fully sampled.
When you set a higher oversampling rate, like 3×3 or 4×4, it takes longer to calculate when rendering.
With the default Adaptive, the quality will be equal to that with Shade Scan Line, and with 2×2, it will be equivalent to that with Shade Ray Tracing with Adaptive set.
As for the oversampling, the setting value is individually specified for each object; the largest “sampling level: 5” can be set only for objects.
Render Background
When this checkbox is on, the background of the rendering image is displayed.
The CALLISTO renderer can draw only Haze in the Background window of Shade. To apply the Shade background, the CALLISTO BgHelper plug-in must be used.
Reflect Background
When this checkbox is on, the background will be applied to reflection from and transmission through materials.
As with the case of Render background, only Haze in the Background window is supported. To apply the background, a background image rendered beforehand must be used in the Environment mapping.
Render Shadows
By turning on this checkbox, you can render shadows in the image.
CALLISTO allows speedy calculation for the Ray Trace Shadows, but does not support Shadow Map.
Number of Threads
By setting the number of threads to 2 or more, you can perform rendering efficiently on a computer with multiple CPUs. Since CALLISTO does not support Auto, you need to manually specify the number of CPUs in your computer.
When the number of threads is set to 2 or more, the image to be rendered will be divided before rendering. How to divide the rendering image is specified in Tile division of the Rendering options in the CALLISTO Information window.
Ray Cast Level
In CALLISTO, you can individually specify the precision of calculation for tracking reflected or refracted images, and its upper limit can be set in this parameter. The value ranges from 0 to 128. A transparent surface for which refraction is not set won’t be affected by Ray cast level and will be calculated to the penetralia of the scene.
Ray Tracing Quality
By setting this parameter, you can easily specify both RGBA threshold (determines the anti-aliasing precision) and Cutoff intensity (determines the calculation precision for light sources). The quality ranges from 0 to 100, and the corresponding setting is shown below:
Setting RGBA threshold
Setting Cutoff intensity
The quality is adjusted so that it will achieve almost the same level in Shade when these parameters are set to 50. However, if you set an extreme value, a satisfactory quality may not be achieved, or the calculation time wasted for objects that are not visible. The recommended value is between 30 and 80 when rendering a typical scene.
RGBA threshold in Rendering options and Cutoff intensity in Light information in the CALLISTO Information window are automatically set according to the value set for Ray tracing quality, as show in the tables above. You can use the values as a reference for your custom settings.
CALLISTO Information Window
When you choose CALLISTO Information from the view menu, the CALLISTO Information window is displayed. Detailed CALLISTO rendering options and the custom and light information for objects that are specific to CALLISTO are specified in this window.
Switch the view of the window by clicking the Shape, Distant Light, or Rendering options tab in the upper part of the CALLISTO Information window and make your settings.
Shape Information
Allows you to display or edit the shape information specific to CALLISTO.
The parameters are activated when you click the Create custom attribute button to embed the custom information. When no information is needed, click the Delete custom attribute button. For a special object that requires the custom information, the Delete custom attribute button will not be displayed or will be dimmed.
Basic Information
Allows you to specify the settings for shapes including anti-aliasing, Path Tracing, etc.
Sampling Rate Max
Using Sampling rate max, you can increase the number of samples in the anti-aliasing process.
By increasing this parameter for a shape that contains finer details than the surrounding shapes, you can improve the anti-aliasing quality just for the specified shape, while the anti-aliasing process for the surrounding area remains rough.
Sampling Rate Min
Using Sampling rate min, you can start the anti-aliasing process with many samples from the beginning. When rendering an extremely fine shape, set Sampling rate min to 3 or 4 in order to alleviate the phenomenon where a fine shape is rendered in pieces.
Sampling rate max should be equal to or larger than Sampling rate min.
Because “Sampling rate: 5” consumes much memory, apply it only to parts that need it.
In the default state, both Sampling rate max and Sampling rate min parameters inherit the settings of the above part.
Adaptive Surface Tessellation
With this parameter, you can specify the automatic subdivision of curved surfaces in detail. By choosing disable or enable from the pull-down menu, the automatic subdivision of curved surface will be set to on or off for each object.
In CALLISTO, the automatic subdivision is not carried out for every object. If a curved surface or revolved object is covered with a closed line object, you must set Adaptive surface tessellation to disable.
Since the closed line object is not automatically subdivided, space is left between the objects. When Adaptive surface tessellation is set to disable, the space is not left.
When Adaptive surface tessellation is used, you cannot use a morph joint or distance mapping. To use these unsupported functions, set Adaptive surface tessellation to disable.
Tessellation Mode / Tessellation Parameters
Used to specify the criteria for Adaptive surface tessellation by selecting from four modes: screen, world, angle, and level.
Interpretations of Tessellation mode and Tessellation parameters
In any case, the number of subdivisions will not exceed the Max Tessellation level set in the Rendering options. The subdivision is carried out at least once. When using screen mode subdivision with a high resolution, a huge amount of memory may be consumed. It is recommended that the value of Max Tessellation level in the Rendering options be set smaller than the default value, when you render an image at printing resolution.
When only part of a large curved surface is caught by a camera (such as in the case of a Flythru), large amounts of memory may be required. For stable Flythru animation rendering, World or Angle tesselation mode is recommended.
For a complex curved surface, such as winding pipes, use a lower number of Tessellations in the level mode, which allows a reduction in memory consumption without causing a noticeable change in the image.
Smoothing Settings for a Polygon Mesh
The following parameters are uniquely used by CALLISTO to perform the smoothing calculation for a polygon mesh.
Although most polygon meshes are rendered as-is by the Shade standard renderers, the surface of a polygon mesh may be flipped when a complex hierarchy or link is formed at a flipped part.
To correct such improper results, you can use the CALLISTO plug-in to automatically calculate the normal lines.
In the right link object, which was flipped around, the polygon mesh shapes are rendered improperly.
Automatic Polygon Normal Calculation
By choosing disable, or enable from the pull-down menu, you can select either CALLISTO plug-in or Shade to perform the smooth shading for a polygon mesh.
• Disable: Uses the result from the Shade calculation (default)
• Enable: The normal lines for the polygon mesh are calculated by CALLISTO
When enable is specified, the smooth shading for a polygon mesh adopts the Smooth crease angle in the CALLISTO shape information, not the smooth threshold angle of Shade.
For the polygon mesh that is the parent of the Link, Automatic polygon normal calculation is set to enable and smooth crease angle is used. Because of these settings, the flipped polygon mesh is properly rendered.
Smooth Crease Angle
With Automatic polygon normal calculation set to enable, when performing the smooth shading for a polygon mesh with the CALLISTO plug-in, you can use this parameter to specify the smooth threshold angle for the polygon mesh.
The units for this parameter are degrees, ranging from 0 to 180.
When zero is specified, no smooth shading is carried out. When you set it to 180, smooth shading is performed for all polygons in the polygon mesh. By selecting inherited, the setting of the parent part is inherited.
Clean Polygon Points
With the Adaptive surface tessellation checkbox in the Rendering options off, or Adaptive surface tessellation in the Shape information set to disable, when Automatic polygon normal calculation is enable for a curved surface, the smooth shading angle for the curved surface adopts the setting of the Smooth crease angle.
In this case, for a curved surface consisting of line objects with anchor points that have no handles, the vertices of the subdivided polygons are sometimes overlaid at the same or extremely close positions, which may lead to unexpected smooth shading.
When you set enable for Clean polygon points, you can obtain satisfactory smooth shading, because the vertices of the subdivided polygons are arranged correctly.
Visibility for Primary Rays
By setting invisible for Visibility for primary rays, you can create objects that will only be seen in a mirror or through glass, or an object that casts only its shadow and cannot be seen by the camera directly.
By default (inherited), the setting of the parent part is inherited.
The object for which invisible is applied is not rendered in the view seen from the camera directly. However, its shadow, reflections, and refraction are expressed because other objects are referencing the invisible object.
Surface Attribute Side
You can specify the side of a surface to which the surface attribute set for an object is applied. When both is selected, the setting is effective for both sides as usual. Front is only effective for the front side, and the back side inherits the surface attributes of the parent part. Back is only effective for the back side, while the front side inherits the surface attributes of the parent part.
When applying a red surface attribute to a curved surface while a gray surface is set for the parent part, the Surface attribute side parameter affects the curved surface as shown in the following table:
For Displacement Mapping and Trim Mapping, the settings are effective for both sides, regardless of the above setting.
Material Composite
The following parameters are activated only for a CALLISTO Compo Joint, which is a special type of joint used to create composite surfaces, and which will be explained later.
Surface Composite Type
You can choose from four types of material composite Joints using a Compo joint:
• None: No synthesis is performed. Rendered as usual.
• Under: Alpha-blend is carried out from the top of the Browser.
• Over: Alpha-blend is carried out from the bottom of the Browser. When you set this for a Compo Joint at the top, only the material of the original object is rendered.
• Plus: The brightness value multiplied by the composite ratio is simply added.
Composite Factor Attenuation
Used to change the composite proportion with the Compo Joint according to the angle formed between the sight line and the object surface.
Composite factor attenuation: 0
Used to specify the intensity of a surface horizontal to the sight line. In most cases, this parameter setting affects the area around the outline of the object.
Composite factor attenuation: 90
Used to specify the intensity of a surface vertical to the sight line. In most cases, this parameter setting affects the area around the front view of the object.
Composite factor attenuation: Exp
Used to specify the intensity that varies from around 0 to around 90 degrees.
Path Tracing Settings
This parameter allows you to turn Path Tracing on or off, and specify the precision, for an individual object.
High-quality indirect light can be calculated only for necessary areas, without reducing the rendering speed for the whole scene.
Ray tracing Level
Used to specify the Path Tracing level for the selected object. For Inherited, the setting of the parent part or the Rendering options is inherited. When you specify 0, the Path Tracing calculation is not performed for the selected object. When 1 is set, regardless of the setting of Rendering options or the above part, the indirect light will be calculated with Path Tracing for the selected object.
Number of Rays
Use this parameter when you want to change the number of Path Tracing rays for an object. When Inherited is selected, the setting for the parent part is inherited. If the parent part has no setting, the value set in Rendering options will be used.
Light Information
Allows you to display and modify the Light information specific to CALLISTO.
Basic Information
Intensity / Visible
Used to specify the intensity of a light source. For Distant lights, Point lights, Spotlights, and Area lights, the intensity value is tied to the setting in the Distant Light window or the Light dialog in Shade.
The intensity of a spherical light / Geometry light is equal to the Intensity in the Shade Light dialog, and the intensity of sky light is equal to that of Distant light.
Visible
Used to determine whether a light source is displayed or not. This parameter is the same as Visible for a Shade Area light.
Cutoff Intensity
By avoiding calculations for dark areas in the rendered image, you can reduce the rendering time.
The Cutoff intensity setting consists of two parameters (OUT and IN) and the Auto checkbox.
When the Auto checkbox is turned on, the Cutoff intensity specified in the Rendering options of the CALLISTO Information window is applied. If Auto is also checked in the Rendering options, the value in the Ray tracing quality of the Shade Rendering options is automatically used.
When a light intensity is smaller than the value specified in OUT, the intensity calculation is discontinued. If the intensity is larger than the OUT value and smaller than the IN value, it will be linearly attenuated to zero at the OUT position. OUT should be equal to or smaller than IN.
Although the effective setting ranges from 0 to 1 for both OUT and IN, the recommended value generally ranges from 0.006 to 0.1.
Since the Distant light and sky light are not attenuated, a Cutoff intensity cannot be specified for them. It is also disabled for Photon mapping.
Cutoff Distance
As with Cutoff intensity, this parameter optimizes the calculation of a light, but unlike the Cutoff intensity, the cutoff is specified as a distance from the light source, not an intensity.
The Cutoff distance setting consists of two parameters (OUT and IN) and the Auto checkbox.
When the Auto checkbox is turned on, the Cutoff intensity specified in the Rendering options of the CALLISTO Information window is applied. If Auto is also checked in the Rendering options, the calculation distance cutoff is not carried out.
No light calculation is performed for the area where the distance from the light exceeds OUT. When the distance specified in OUT is longer than the distance specified in IN, the intensity will be linearly attenuated to zero between the IN and OUT positions. OUT should be equal to or larger than IN.
When you render the interior of a building or the like, set the room size to OUT for the light source, for a drastic reduction in rendering time.
Since the Distant light and sky light have no position, a Cutoff distance cannot be specified. It is also disabled for Photon mapping.
Photon Mapping
Used to specify the Photon mapping attributes of light and the type of sky light.
Use Photon Map
This checkbox determines whether photons are radiated from the selected light or not.
For sky lights, Spherical lights, and Geometry lights, this checkbox is always turned on.
Since Photon mapping does not support Linear attenuation, an alert box appears saying “Photon Mapping does not support Linear attenuation. Change it to Quadratic attenuation?”, when you check Use photon map for a Point light or Spotlight for which Linear attenuation is specified.
Number of Photons
Used to specify the number of photons radiated from the selected light. By increasing the number of photons, you can calculate more accurate brightness, but the calculation time is also increased.
When rendering, the number of photons specified in this parameter are multiplied by Number of photon multiplier of the Rendering options in the CALLISTO Information window. Using this value, the brightness in the scene is calculated.
Normally, there is no need to set this parameter for each light source. However, the time required for rendering can be optimized by changing the Number of photons.
Use Illuminances for Direct Light
When rendering using Photon mapping, you can specify whether illuminance is used or not for the brightness calculation of direct light. With this checkbox off, the brightness is calculated for the surface of an object in the same manner as Ray Tracing or Distribution Ray Tracing, like Shade Photon mapping.
Use illuminances for direct light checkbox is ON
Use illuminances for direct light checkbox is OFF The direct light from the spotlight is calculated with a normal Ray Trace, while only the indirect light is calculated with the photon map stored in the illuminance.
Number of Samples
Used to specify the number of samples (number of rays in Distribution Ray Tracing) when performing the brightness calculation for an Area light or sky light without using Photon mapping.
By increasing the number of samples, the light can be accurately calculated and the granularity will be decreased, while the calculating time gets longer.
Area light and Number of samples
sky light and Number of samples
Sky Light Types
CALLISTO supports four types of sky lights.
You can use multiple sky lights simultaneously.
Color
Uses the base color for the brightness of the sky.
Example of a Color-type sky light
This light is radiated from the sky light with the same brightness, until reaching the area around the horizon line.
Overcast
Simulates an overcast sky.
For the brightness in the directly-above direction of the skylight, the color specified in the Base color of the CALLISTO SkyLight object is used.
By using the standard functions of CIE (International Commission on Illumination), the brightness of the sky light is calculated for each position.
Example of an Overcast-type sky light
This light is naturally attenuated from the zenith, producing a strong spatial effect.
Clear
Simulates a clear sky.
For the brightness in the directly-above direction of the skylight, the color specified in the Base color of the CALLISTO SkyLight object is used.
The direction of a line segment coming from the center of a disk in the Figure window is the direction of the sun, and the direction can be modified using Rotate in the Shade move tool.
When the Clear-type sky light is selected, a line segment indicating the direction of the sun is displayed, coming out from the center of the CALLISTO SkyLight object.
Since no direct light from the sun is calculated, you have to use this light together with a Distant light.
Rendered result, after aligning the directions of the CALLISTO SkyLight object and the Distant light.
The upper-left image was calculated with only the Clear Skylight.
Environment
Image-based mapping is used.
The image used with Environment mapping in the Surface window is used to control brightness for a CALLISTO SkyLight object. Using a Panoramic picture, you can achieve a highly realistic sky light.
Example of an Environment-type sky light
The bottom figure shows the Panorama image used for the Environment map.
Illuminance Information
The Illuminance object is used to save the result of the Photon mapping calculation.
With this Illuminance information, you can specify parameters, such as sampling precision for photons or filter size, that determine the precision of rendering.
To make an Illuminance information setting, select one of the illuminance objects (named “Global:” and “Caustic:” upon creation of the Illuminance part) contained in the CALLISTO Illuminance part and open Illuminance information using the Shape button in the CALLISTO Information window.
Applicable Scope of Illuminance
The illuminance effective for a Distant light is the illuminance that exists in the immediate child hierarchy of the root part.
In the case of any other light, the illuminance which is the immediate child of the part including the light is enabled. If such illuminance does not exist, an illuminance as an immediate child of the parent part is enabled (which is found first when you are tracing the parent part). If multiple illuminances are located in a single part, the first one is used.
Adjust Range
Clicking Adjust range allows you to set the illuminance range to the next larger size, so that it accommodates all objects in the scene.
Filter Type
This specifies the type of filter used for collecting photons stored in an illuminance when rendering.
In the Filter type pull-down menu, choose from the four types: cone, gauss, cos, and cylinder.
Cone Filter
This is a High-speed filter that collects the most photons.
When plenty of photons are stored in an illuminance, this type can be used in most cases.
Rendered with the cone filter
Left: Filter size is the same as Sample width
Right: Filter size is four times larger than Sample width
The caustics effect is blurred, as compared with the gauss or cos filter.
Gauss Filter
This filter can produce a high-contrast, smooth result and is used for final rendering with Photon mapping. It takes longer to calculate than cone.
Rendered with the gauss filter
Left: Filter size is the same as Sample width
Right: Filter size is four times larger than Sample width
The finished image has higher contrast than with cone.
Cos Filter
This filter also produces a high-contrast, smooth result and can be used for final rendering with Photon mapping. It works a little faster than gauss.
Rendered with the cos filter
Left: Filter size is the same as Sample width
Right: Filter size is four times larger than Sample width
This is almost the same as gauss, though it has slightly lower contrast and works faster.
Cylinder Filter
This filter takes the least time to collect photons. Since its quality is not suitable for a finished work, use it for checking or testing your work.
Rendered with the cylinder filter
Left: Filter size is the same as Sample width
Right: Filter size is four times larger than Sample width
The left figure was rendered fairly quickly. This is best suited for checking the state of photon mapping.
Filter Size
When rendering with photons stored in an illuminance, you can specify the range over which the individual photons will affect the brightness calculation for a surface.
When you set the illuminance Filter size to a value larger than the Sample width, the haze becomes unnoticeable but the details of the lighting effect using Photon mapping are also lost.
When Filter size is increased, the calculation time will increase because the area used for searching for photons is expanded.
When the Relative checkbox is on, the Filter size value is relative to the illuminance range.
Sample Width
Sample width is a parameter corresponding to the resolution of the photon map. With this parameter you specify the width between sample points for the photon map. When a smaller value is set, the precision of the Photon mapping calculation will increase, and the calculation time and memory consumption will also increase.
When the Relative checkbox is on, the illuminance sample width is relative to the Illuminance filter size.
Note: Changing the Sample width value requires recalculation of the photon map.
Note: When the Relative checkbox is on, note that the Sample width value will change as the Filter size changes.
Distant Light
By choosing Distant light in the CALLISTO Information window, you can specify CALLISTO light information for a Distant light.
Distant Light Index
The number of the light selected in the Distant light window is displayed.
Create Custom Attribute / Delete Custom Attribute
The Distant light parameters can be enabled by embedding the custom information with the Create custom attribute button. When the information is no longer required, click the Delete custom attribute button.
Intensity
Used to specify the intensity of the light source. This parameter is tied to the value in the Shade Distant light window.
Using Photon Mapping
This parameter operates similarly to Use photon map in the Light information.
Refer to the Light information description.
Since Distant light is a light source that does not attenuate, no alert appears when switching on Use photon map.
Number of Photons
This parameter operates similarly to Number of photons in the Light information. Refer to the Light information description.
Since Distant light radiates over a wider area, it requires more photons than other light sources when no illuminance object is used.
Use Illuminances for Direct Light
This parameter operates similarly to Use illuminances for direct light. Refer to the Light information description.
Number of Samples
This parameter operates similarly to Number of samples. Refer to the Light information description.
Since the quality of shadow softness for a Distant light is relatively high, there is no need to set a value as high as for an Area light or sky light.
Rendering Options
Now we will explain the rendering settings that are specific to CALLISTO. The CALLISTO renderer has a variety of functions including sophisticated anti-aliasing for professional use, settings used to optimize rendering time, and the simulation of global illumination using Photon mapping. The settings under Rendering options tab of the CALLISTO Information window will be referred to as the CALLISTO Rendering Option .
There are many rendering settings, but not all of them need be used.
Basic Information
Adaptive Surface Tessellation
When you turn on the Adaptive surface tessellation checkbox, curved surfaces and revolved objects are subdivided into micro polygons for rendering.
By turning off this checkbox, the rendering is performed after they are subdivided into polygons, just as with the Shade standard renderers, and the Surface subdivision specified in the Shade Rendering options dialog is enabled.
Adaptive surface tessellation not applied
Surface subdivision in the Shade Rendering options dialog: Regular
Adaptive surface tessellation applied
Max Tessellation Level
Tile Division
Tile division consists of the number of horizontal tiles, number of vertical tiles, and the Auto checkbox. When Auto is selected, the number of tiles is automatically specified according to the number of threads.
Use this parameter to perform multi-threaded rendering efficiently when objects are placed disproportionately in a scene as viewed from the camera.
Auto checkbox: Off
Number of horizontal tiles: 6
Number of vertical tiles: 1
Color Tiles Before Rendering
When performing multi-threaded rendering, each tile is covered with a color that varies with the thread, immediately before rendering the tiles.
Step
When specifying Step, you can perform Step rendering, while the size of the rendered image specified in Shade remains the same. The left value is for the horizontal step rate and the right value is for the vertical step rate.
With this value set to 2, CALLISTO renders a half-size image. When the value gets larger, the image will be coarser but the rendering can be finished at high speed.
Example of rendered image with a Step of 10x10
Clamp Color
This parameter limits each RGB channel value to 0 to 1.0 for a rendered image. With this parameter, you can restrain a phenomenon where the ultra highlight area (extremely bright area or white, missing area of reflected image) spreads when the value of Filter size in the Anti-aliasing setting is large.
Shade can save the region above 1.0, which are used by the Correction window or Effector plug-ins. When Clamp color is checked, the settings of the Correction window and the effect of some Effector plug-ins become incorrect.
Original image
Clamp color: OFF / Correction
Clamp color: ON / Correction
Highlight areas disappear and turn gray.
Walkthrough
With the Walkthrough checkbox on, when creating an animation, the scene data is sent to the CALLISTO renderer for the first frame, and only the camera information is sent to it for the following frames.
The CALLISTO renderer converts Shade objects into a form specific to CALLISTO and sends it to the CALLISTO renderer to be rendered. When Walkthrough is not checked, the Shade objects have to be converted for all frames, which wastes time. By turning on this checkbox, you can reduce the time required for converting the objects.
When you create an animation where only the camera moves, it is recommended that the Walkthrough checkbox be turned on.
This checkbox does not affect the rendering of still images.
Background Alpha =0
With this checkbox on, when the background is set to be displayed and rendered, the alpha value of the background area will be zero. With this checkbox off, the value will be 1.
Max Reflection Level
With Max reflection level, you can specify the ray cast level for reflections, independent of that for refraction.
For the areas beyond the cast level, surface attributes calculated with any parameter other than reflection are rendered.
Note that the Ray cast level in the Shade Rendering options dialog is used as the upper limit.
Max reflection level: 2,
(Default value) Rendering time: 27 seconds
Max reflection level: 5, Rendering time: 33 seconds
Max Refraction Level
With Max refraction level, you can specify the ray cast level for refraction, independent of that for reflection.
Note that the Ray cast level in the Shade Rendering options dialog is used as the upper limit.
CALLISTO renders the scene to the penetralia even if multiple objects with transparency applied are piled up. The refracted image drawn for surfaces with refraction applied is traced only for the number of times set for the ray cast level for refraction.
Max refraction level: 0, Rendering time: 29 seconds
Max refraction level: 8, Rendering time: 66 seconds
Distributed Ray Tracing
With the Distributed ray tracing checkbox off, Distribution Ray Tracing will not be carried out even if a light source with Shadow Softness set, or a material with the Roughness surface attribute applied, exists in the scene.
In the default state, this checkbox is turned off.
Area light, Spherical light, Geometry light, and sky light are calculated in a manner similar to Distribution Ray Tracing, regardless of this checkbox.
Number of Rays
Used to specify the number of rays when Distribution Ray Tracing is used. In CALLISTO, Distribution Ray Tracing is carried out for the necessary areas to which Area light, Shadow softness, and Roughness in the Surface window is applied.
In the Distribution Ray Tracing of Shade’s standard renderers, the rays are automatically increased until the quality set in Ray tracing quality of the Shade Rendering options dialog is achieved, while CALLISTO Distribution Ray Tracing uses the predetermined number of rays.
Intensity Scale
Rendering is performed after the intensity of every light source is multiplied by the Intensity scale value. Use this parameter when you want to adjust the lighting for the entire scene.
In Shade, the intensity of light sources is not affected when the entire scene is zoomed in or out, while with this option the balance of the light intensity can be adjusted.
Unlike the color correction in the Correction window, this parameter has no effect on the Glow surface attribute or the background.
Z Range
The Z range is defined by the minimum and maximum values of the distance from the camera. Objects outside this range are not rendered.
Z range consists of two parameters (minimum and maximum) and the Auto checkbox.
With Auto on, the Z range is calculated automatically so that the whole scene is included.
By turning off the Auto checkbox, you can specify the minimum and maximum values of the Z range individually.
Auto Checkbox: OFF
Minimum value: 4190 (Distance between the camera and the center of the object)
The area before the minimum value is not rendered.
Cutoff Intensity
Used to specify the Cutoff intensity of light. Though the value specified in the Rendering options is applied to all light sources (except Distant lights), the setting of the lights for which the Cutoff is individually set is not inherited.
Ref: For details on Cutoff intensity, refer to the Cutoff intensity in the Light information of the Shape information.
Anti-aliasing
Filter Type
This parameter allows you to select the method used to average the sampling points in the anti-aliasing process. Select box, gauss, or cos in the Filter type pull-down menu.
The box filter works fast, but the anti-aliasing precision is low and some effects such as reduction of moiré patterns cannot be expected.
The gauss filter has a high anti-aliasing precision and greatly reduces moiré patterns. Compared with the cos filter, the result tends to be flat.
The cos filter has a high anti-aliasing precision and reduces moiré greatly. Compared with the gauss filter, the result tends to be high-contrast.
RGBA Threshold
The CALLISTO anti-aliasing process will be performed when there is a certain difference in color between adjacent pixels in the rendered image or between sampling points in anti-aliasing.
With this parameter, you can directly specify the difference in color that determines whether antialiasing is performed or not.
RGBA Threshold Setting
Generally, there is no need to specify the RGBA threshold. Use this parameter when you want to independently set the lighting calculation quality with Cutoff intensity and the quality of the anti-aliasing process.
Z Threshold
CALLISTO has a function to perform anti-aliasing based on depth.
When Z threshold is set larger than zero (default), the anti-aliasing process is carried out whenever the difference in depth between adjacent pixels in the rendered image or between sampling points is greater than the set value.
The value should be a real number greater than zero, and the units of the Shade Figure window are used. By decreasing the value, the quality of the antialiasing will be improved, while the rendering time gets longer.
If a number of surface attributes such as reflection (to simulate metal plating) are used, the outlines of objects may approximate the background very closely. In this case, using Z threshold allows proper anti-aliasing for such outlined areas. This parameter also works effectively for reflected images or bumpy areas that look like refracted images.
Z threshold: 0 (Default value)
When Z threshold is zero, only the difference in color is considered for the anti-aliasing process. Thus, if there are many similar colors in the image as shown in the above Figure, the anti-aliasing process does not fully work.
Z threshold: 10
When Z threshold is specified, the anti-aliasing process works for areas with a difference in depth, even if the image has similar colors.
When you set Ray tracing quality to a lower value (e.g. 30) or RGBA threshold to a larger value, specify the Z threshold to reduce the rendering time, because then the anti-aliasing is only performed for bumpy areas and outlines that are seen from the camera.
Filter Size
With the Filter size setting, you can independently specify the anti-aliasing range to be processed in the X and Y directions, using the pixel size in the rendered image.
Filter size consists of two parameters: Filter size in the X direction and Filter size in the Y direction. (Note that these are screen coordinates, not the X and Y axes of the 3D modeling space.)
The values must be real numbers from 0 to 3, and the default value is 1. When the default value is set, the anti-aliasing range to be processed will be within 1 screen pixel.
Although the value 1 is good enough for normal cases, you may have to specify 2 or larger to reduce the moiré patterns for a still image printed at high resolution, which may generate one dot using 4 or more adjacent pixels.
In the case of images to be used on the Web, in which the pixels of the rendered image and the pixels of the output image correspond one-to-one, a sharp antialiased image can be obtained by setting the value around 1.0, i.e., from 0.75 to 1.25.
In animation, to reduce flicker in a series of frames, use a larger value like 1.25 to 2 to soften the outlines and patterns of objects.
By specifying different values for the X and Y directions, you can use this anti-aliasing for images to be used with NTSC video, for example, in which the resolution is different in the vertical and horizontal directions.
Filter size in the X direction: 1.5, Filter size in the Y direction: 3
Horizontal stripes are very blurred.
Mapping Filter Size
With the Mapping filter size parameters, you can specify the amount of blurring in image mapping. Mapping filter size consists of two parameters: Filter size in the X direction and Filter size in the Y direction.
By setting this parameter to 1:1 (default value), the result will be almost the same as that of Smooth specified in the Shade Surface window. When zero is set, the filtering is not carried out for the mapping image. Use this parameter to reduce animation flickering or to eliminate moiré patterns when lots of grating-type mapping is used.
Filter size in the X direction: 3.0, Filter size in the Y direction: 3.0
Since flicker will often occur in Walkthrough animation, setting this value to 1.0 or greater can be effective.
Camera Jittering
Using Camera jittering, the sampling points used for antialiasing are randomly positioned to reduce the quantized moiré effect (a periodic pattern occurring when a pattern is repeatedly put into grating data).
Camera jittering consists of two parameters: Jittering size in the X direction and Jittering size in the Y direction.
The values are real numbers ranging from 0 to 1.
Jittering size in the X direction: 0.3, Jittering size in the Y direction: 1
This parameter is effective for moiré-sensitive, highresolution images for printing, although the finished work will have some noise.
Since the sampling points change randomly, is not recommended for animation.
Photon Mapping
Use Photon Map
When the Use photon map checkbox is on, photon mapping is used in rendering.
With the Use photon map checkbox off, photon mapping is disabled even if photon mapping is specified for a Light or an illuminance is created.
Even when the Use photon map checkbox is on, photon mapping is not performed unless a light exists with Use photon map selected in the Light information.
Number of Photon Multiplier
The number of photons obtained by multiplying the number of photons specified for each light source by Number of photon multiplier will be used to calculate the photon map.
The value is a real number, starting from 0, and the default is 1.0. When a larger value is set, the calculation precision is increased, while the time required for calculating the photon map gets longer.
Number of photon multiplier is used to control the quality of rendering with Photon mapping for the whole scene.
The default number of photons is 10,000 for each light. When a single light source is located and Number of photon multiplier is set to 100, 1,000,000 photons are used to perform the calculation for the entire scene. As Number of photon multiplier gets larger, the time requiring for the Photon mapping calculation will increase.
Number of photon multiplier: 1
Time for the Photon mapping calculation: 4 seconds
Total rendering time: 54 seconds
Number of photon multiplier: 10
Time for the Photon mapping calculation: 13 seconds
Total rendering time: 62 seconds
Number of photon multiplier: 100
Time for the Photon mapping calculation: 134 seconds
Total rendering time: 183 seconds
In the following cases, you should increase the Number of photon multiplier:
• When haze patterns occur: One of the reasons the haze occurs when Photon mapping is used is that the Photon mapping calculation is too sparse. To eliminate the haze, you must increase the Number of photon multiplier.
• When Illuminance sample width is changed to a smaller value: When you lower the value of Illuminance sample width, the photon map resolution is increased, which requires increasing the Number of photon multiplier to calculate the high-resolution photon maps accurately.
• When rendering an area where light hardly reaches: It is difficult to distribute photons all around the room, particularly for a scene in which the indirect light comes from the sun and shines into an indoor area. To solve this problem, you need to increase the Number of photon multiplier.
Max Diffuse Reflection Level of Photons
With Max diffuse reflection level of photons, you specify the number of times the calculation of indirect light using photons traces diffuse reflections. The value should be an integer from 0 to 128, which is limited by the Ray cast level of the Shade Rendering options.
Indirect light will be calculated when this value is 1 or greater. To distribute the light over a complicated area, specify a larger value. In this case, the time for the Photon mapping calculation will increase.
Max diffuse reflection level of photons: 0 Time for the Photon mapping calculation: 13 seconds No indirect light is rendered at all.
Max diffuse reflection level of photons: 8
Time for the Photon mapping calculation: 12 seconds
Light can reach the complicated area due to the eight-level indirect light.
Max Specular Reflection Level of Photons
With Max specular reflection level of photons, you specify the number of times the calculation of indirect light using photons traces specular reflections.
The value should be an integer from 0 to 128, which is limited by the Ray cast level of the Shade Rendering options.
By specifying 1 or a larger value, you cause the indirect light to be calculated based on the specular value.
Max specular reflection level of photons: 2
In the real world, there is no material that reflects light that is brighter than the light from the light source. However, a surface for which specular is applied can emit light that exceeds the incoming light.
Therefore, if you set a large value for this parameter, the amount of light may be too much for the whole scene.
Photon Map Calculation
In the Photon map calculation pull-down menu, choose from Always, Only First Frame, and Never for the Photon mapping calculation performed before rendering.
Using the Photon Map Calculation Pull-down Menu
When Photon map calculation is set to Always, the previous photon map which was calculated and saved in an illuminance will be deleted.
The Photon mapping calculation often takes a long time. When a photon map with the final, desired quality is calculated, care must be taken with the state of the Photon map calculation pull-down menu.
The following conditions do not allow the photon map to be reused:
• When the whole scene is resized (when the default illuminance is used)
• When the illuminance object is resized
• When the illuminance Sample width is changed
Compression Format
You can select the compression format used to save the photon map file as gzip or None. Saving the photon map requires a huge amount of space. When you use gzip compression, the time required for saving the photon map will be shortened and the size of the photon map data saved on the hard disk is also reduced. Because the gzip compression works quickly, use this setting (default value) unless you have a particular reason not to.
The photon map size is not affected by the number of photons used, but will be larger when you set a smaller value for Sample width of the Illuminance information (or when you increase the resolution of the rendered image).
Illuminance Filter Type
This specifies the filter to use when collecting photons stored in an illuminance when rendering.
Illuminance filter type in the Photon mapping group of the CALLISTO Rendering options will set the default illuminance.
Note: The meaning of this parameter is the same as that of the Illuminance information in the Shape information.
Illuminance Sample Width
Used to specify the width between sample points for the default illuminance that collects photons stored in an illuminance when rendering.
Illuminance sample width in the Photon mapping group of the Rendering options sets the default illuminance.
Note: The meaning of this parameter is the same as that of the Illuminance information on the Shape tab.
Show Calculation Progress
Turning the Show calculation progress checkbox on will display progress bars in the Image window during the Photon mapping calculation.
Each of the multiple progress bars shows the calculation progress for the illuminance object or photon light sources.
If no illuminance is added by the user, the number of progress bars will be the number of light sources in a scene plus 1 (default illuminance).
Save Photons in Custom Attributes
When you turn on the Save photons in custom attributes checkbox, the calculated photon map is saved in an illuminance object or scene attributes. By saving the photon map in the custom attributes, you can reuse the photon map if the Shade scene file is used on another computer.
With this checkbox off, the calculated photon map is saved in a temporary file, which will be deleted when exiting from Shade or closing the file.
Also note that the photon map may be extremely large. The photon map size is not affected by the number of photons, but will be larger when you set a smaller value for Sample width of the Illuminance information (or when you increase the resolution).
The photon map saved in the custom attributes is compatible with both the Mac OS X and Windows versions.
CALLISTO Temporary Files
CALLISTO will create a temporary file on the local disk to store photon maps and so on. The temporary file is created in one of the following locations, according to the numbered priority:
1. Directory set in Environment variable TMP
2. Directory set in Environment variable TEMP
3. /tmp (Mac OSX version)
4. C:/WINDOWS/TEMP (Windows)
A subdirectory named “CALLISTO_shade_xxxxxxxx_ dddd” (where x is a hexadecimal digit and d is a decimal digit) will be created in one of the locations listed above, and a temporary file is created in that subdirectory.
The above directory is normally deleted when you exit from Shade, but in some cases it may remain on the hard disk. You can delete it manually without adversely affecting CALLISTO or Shade.
Clear Photon Map
If the Save photons in custom attributes checkbox is on, clicking this button will delete the photon map saved in the Shade scene file. Use this to reduce the file size.
Path Tracing
CALLISTO also offers Path Tracing. Unlike the Shade Path Tracing renderer, CALLISTO Path Tracing cannot calculate indirect light properly using only Path Tracing. By performing the Path Tracing for a scene where the photon map is calculated, the drawbacks of Photon mapping, such as haze and photon dropout, can be eliminated.
You can also perform Path Tracing individually for an object, using the Path tracing settings of the Shape information in the CALLISTO Information window.
CALLISTO Path Tracing has the following limitations for Global Illumination.
• Caustics are not supported
• Path Tracing is not calculated for specular high lights
Ray Tracing Level
In the Ray tracing level pull-down menu, select the maximum number of ray reflections or refractions.
When 1 is selected, the primary indirect light will be calculated using Path Tracing.
When 0 is selected, Path Tracing is not performed.
Although CALLISTO Path Tracing only calculates the primary indirect light, you can use it with Photon mapping.
When indirect light from any light source has already been calculated using the photon map, Path Tracing will reference the rendered result of the photon map indirect light, which allows you to render intricate indirect lights.
Use photon map: OFF
Path tracing / Ray tracing level: 1
Path Tracing without using Photon mapping calculates the primary indirect light only.
Use photon map: ON
Path tracing / Ray tracing level: 1
Indirect light is rendered smoothly even in the shaded area.
Number of Rays
In the Number of rays pull-down menu, specify the number of rays for Path Tracing.
As the Number of rays is increased, the indirect light is calculated more accurately, but the rendering time is increased.
Path tracing / Number of rays: 2×2 (Default value)
Rendering time: 32 seconds
Path tracing / Number of rays: 8×8
Rendering time: 308 seconds
Shading Rate Diffuse (Pixel)
In the Shading rate diffuse (pixel) pull-down menu, specify the interval of pixels at which the Path tracing calculation is performed. A larger value will make the calculation faster, but the Number of rays must be increased to a certain level to obtain a smoother image.
Path tracing / Shading rate diffuse (pixel): 0
Rendering time: 394 seconds
Path tracing / Shading rate diffuse (pixel): 2 (Default value)
Rendering time: 88 seconds
Path tracing / Shading rate diffuse: 4
Rendering time: 30 seconds
Filter Diffuse (Pixel)
Filter diffuse (pixel) allows you to specify the filter diffusion when filtering the brightness of the diffusion calculated with Path Tracing on the screen. By increasing the value for this parameter, Path Tracingspecific noise will be reduced. The value ranges from 0 to 20.
When the value of Filter diffuse (pixel) is set to zero (default), it will be twice the value specified in Shading rate diffuse (pixel). With Shading rate diffuse (pixel) set to zero, the Path Trace filter will not be used.
Path tracing / Filter diffuse (pixel): 0 (Default value: 4)
Rendering time: 119 seconds
Path tracing / Filter diffuse (pixel): 16
Rendering time: 125 seconds
CALLISTO Material Window
Select View > CALLISTO Material to display the CALLISTO Material window. This window allows you specify materials specific to CALLISTO, which link with the Shade surface attributes.
Create Surface Attribute / Delete Surface Attribute Buttons
Used to create or delete surface attributes. These work similarly to the Create/Delete buttons in the Surface window.
Create Custom Attribute Button
Adds CALLISTO Material attributes to the selected object or master surface. Unlike the case of the object information, no identifier is added in the Browser. Adding custom attributes does not affect the Shade standard renderers. To delete the custom attributes, click the Delete custom attribute button.
Basic Parameters
In this panel, you can specify the basic surface attributes. The parameters that match the standard Shade surface attributes will be linked to the settings in the Surface window. Here only the the attributes with different names and functions are explained.
Fresnel
At the surfaces of light-transmitting materials such as glass or water, a phenomenon called “Fresnel reflection” occurs frequently.
For example, when you look up from under water, you can see fairly clearly at an angle nearly vertical to the water surface. But when you try to look out horizontal to the surface, the surrounding environment is heavily reflected and you cannot see clearly.
Such a phenomenon, in which the reflection rate or transparency is affected by the angle at which you view the boundary surface of materials, is called the Fresnel effect.
CALLISTO allows you obtain a similar effect by specifying the transparency and reflection rates individually in the Parameter attenuation section. However, using Fresnel, you can easily implement the Fresnel effect because Specular Parameter attenuation, Reflection Parameter attenuation, and Transparency Parameter attenuation are all automatically set.
When Fresnel is set to zero, the Fresnel effect is not calculated. It will be calculated when a value greater than 0 is set, and for a value of 1, the attenuation of Fresnel reflection and transparency that occurs for transparent glass or a water surface will be simulated.
It is recommended that the Fresnel value for transparent materials like glass be set to 0.9 to 1, where the reflection is greatly attenuated.
The value of Fresnel suitable for polished stone, plastic, or resin coating is often within 0.7 to 0.9.
Metallicity
Metallicity is linked with the Metallic parameter in Shade, but simulates a metallic specular surface differently from Shade.
As the Metallicity value becomes larger, the specular color changes from the color of the light source to the color of the material.
Link Attributes with Opacity
In CALLISTO, when rendering surface attributes with transparency, such as glass, any color that exceeds the intensity with which the light source illuminates the object is not rendered. Thus, Diffuse and Emission are automatically attenuated according to the Transparency.
Link attributes with opacity is checked in the initial state. When Fresnel or Transparency Parameter attenuation is used, this parameter works efficiently to increase the Emission or Diffuse level for the low- Transparency area automatically.
When this checkbox is on, the intensity of Diffuse and Emission is automatically specified for Transparency, and the effects specified in Diffuse Parameter attenuation and Emission Parameter attenuation are ignored. To attenuate Diffuse or Emission, you must turn this checkbox off.
Ambient
Used to specify the reflection rate for the Ambient value of the Distant light.
Anisotropic
This panel allows you to specify Anisotropic settings specific to CALLISTO.
The CALLISTO Anisotropic function is also effective for a polygon mesh to which UV Mapping is applied.
Use Shade Parameters
Disable this checkbox to use CALLISTO’s Anisotropic settings.
Synchronize Parameters with Shade
With this checkbox on, the settings of the CALLISTO Material window are synchronized with the Anisotropic Shade surface attribute.
Turning off this checkbox allows you to specify different Anisotropic values for Specular 1 and Specular 2.
Specular 1 U / Specular 2 U
Used to specify the direction of line objects forming a curved surface which is Switched, or the Specular size in the U direction of a polygon mesh to which UV Mapping is applied.
Specular 1 V / Specular 2 V
Used to specify the direction of line objects forming a curved surface which is not Switched, or the Specular size in the V direction of a polygon mesh to which UV Mapping is applied.
Distributed Ray Tracing
The Distributed ray tracing panel allows you to specify the number of rays of Distributed Ray Tracing for each surface attribute.
Distribution
With the material parameter of CALLISTO equivalent to the “Roughness” of a surface quality-of-the-material window, the “roughness” of the surface quality of the material is interlocked with.
Number of Reflection Rays / Number of Refraction Rays
By switching this checkbox on, you can modify the Distributed Ray Tracing quality for each material.
When zero is set, the value specified in the Rendering options in the CALLISTO Information window is used.
Attenuation at Varying Angles
To produce a realistic or fantastic material, CALLISTO allows you to change the degree of application of the surface attributes depending on the angle formed by the sight and normal lines.
The Parameter attenuation parameters, which can be used to specify five surface attribute parameters (Specular / Reflection / Transparency / Diffuse / Emission), consists of the following three parameters for each surface attribute:
0 degrees: Specify the extent to which each surface attribute parameter is attenuated or amplified for the front view of the object, as seen from the camera (point 1 in above figure).
90 degrees: Specify the extent to which each surface attribute parameter is attenuated or amplified for the silhouette edges of the object, as seen from the camera (point 2 in above figure).
exp: Specifies the intensity of change in attenuation rate when it shifts from 0 to 90. When the exp value is increased, a rapid change occurs in the silhouette edges (point 3 in above figure).
The right object has standard surface attributes, while the following values are set for the Diffuse of the left object.
Parameter attenuation, 0: 1.00 (Default value)
Parameter attenuation, 90: 1.50
exp: 1.00 (Default value)
On the spider’s body, the following values are set for the Parameter attenuation of Emission.
Parameter attenuation, 0: 0
Parameter attenuation, 90: 1.00 (Default value)
exp: 1.75
Metallic
The Metallic shader is often used for obtaining a metallic sheen effect, as found on an automobile body.
Note: The Metallic and Translucent shaders cannot be used on spheres. You must first convert the sphere to a curved surface before using these shaders.
Note: Depending on the level of surface detail on the object being rendered with the Metallic shader, the total number of particles may become very large and rendering time may increase considerably. By default the particle size is optimized for an object of approximately 150mm x 150mm. If you are using the Metallic shader on an object larger than this, consider inccreasing the particle size in order to achieve a balance between detail and rendering time.
Diffuse
This value is one component of the diffuse reflection used for Metallic shading. Depending on the angle between the eye vector and the normal of the face, the falloff color may also be visible. If the Diffuse value is set to 0, the diffuse value specified for the Surface Attributes will be used instead of the Callisto Diffuse attribute.
To use a sphere as an example, the contribution ratio decreases and the sphere becomes gradually more transparent moving from a point horizontal to the line of sight to a point at right angles (90 degrees) to the line of sight. The contribution ratio’s rate of change is linear and cannot be modified. If you wish to modify the contribution ratio’s rate of change you must use a composite joint and overlap two metallic materials.
Falloff
Like the Diffuse value, the Falloff value is also a component of the diffuse reflection for Metallic shading. Falloff is different from Diffuse in that the direction of the Falloff contribution ratio’s rate of change is opposite that of Diffuse. For a sphere, the Falloff contribution ratio decreases, the sphere becomes gradually more transparent, and the Diffuse color becomes more visible moving from a point at right angles to the line of sight towards a point horizontal to the line of sight. The contribution ratio’s rate of change is linear and cannot be modified. If you wish to modify the contribution ratio’s rate of change you must use a composite joint and overlap two metallic materials.
Particle
The Particle parameter sets the strength of the Metallic shader for the object as a whole. If this value is set to 0, no Metallic calculations are made. A value of 1 equals 100% strength. Increasing the Particle value beyond 1 results in increasingly brighter images.
From the left, the Particle value is set to 0, 0.25, 0.5, and 1.0
Particle Density
This parameter sets the particle density of the Metallic shading. The particle density is expressed as a number of particles per unit area of the object’s surface. If this value is 0, the Particle Density parameter is calculated from the average particle size using the following formula: Particle Area = 2 x Pi (Average Particle Size) Density = 1 / Particle Area Total Number of Particles = Total Area / Particle Area For a .bmp file, the Particle Density is 1.0 As the value increases the Particle Density increases. However, if the Particle Density is a very large value, such as “10”, the following changes will also occur: areas in which the particles overlap will decrease; areas of the product will become fragmented; and particles smaller than the specified particle size will appear.
From the left, the Particle Density is set to 0, 0.01, 0.05, 0.1, 0.5, and 1.0
Particle Size
Here you can set the maximum and minimum size (radius) of the particles used for Metallic shading. If the maximum Particle Size is larger than the minimum, the actual size of the particle is chosen randomly from within those limits. If the maximum value is not larger than the minimum, the minimum value is used for the Particle Size.
If the Particle Density is set to 0, the number of particles generated increases as the Particle Size gets smaller. Try to avoid generating an unnecessary number of particles, because the rendering pre-processing time and memory load can be considerable.
From the left, the Particle Size is set to 0.15, 0.25, 0.5, and 1.00
Particle Direction
This value indicates the amount by which the Particle Direction is rotated from the object’s normal. This value can be set between 0 and 1. For example, if the value is 0, all the particles will face in the direction of the object’s normals. If the value is set to 0.5, the actual particle directions will be chosen at random between 0 and 45 degrees from the object’s normals. If the value is set to 1, the actual particle directions will be chosen at random between 0 and 90 degrees.
From the left, the Particle Direction is set to 0.0, 0.5, and 1.0
Pigment Specular
Similar to the regular specular value for objects, the Pigment Specular value sets the highlight intensity of the pigments. Increasing this value results ina stronger highlight intensity.
From the left, the Pigment Specular is set to 0.0, 0.05, 0.25, 0.5, 0.75, and 1.0
Pigment Specular Size
This value is similar to the regular specular size value for objects, and represents the size of the pigment specular value.
From the left, the Pigment Specular Size is set to 0.0, 0.05, 0.25, 0.5, 0.75, and 1.0
Pigment Reflection
This parameter sets the strength of the pigment reflection.
From the left, the Pigment Reflection is set to 0.0, 0.5, and 1.0
Translucent
These parameters are used to set the translucency attributes. With the Translucency shader you can express subsurface scattering, the effect of light bouncing inside of a transparent object and exiting through the surface. Subsurface scattering can be used in marbles or other translucent objects. Callisto does subsurface scattering calculations in one of two ways: either as single-scattering or as multi-scattering.
Single-scattering means that the light entering the translucent object scatters only once inside the object, and then exits the object at a different point from which it entered. Multi-scattering means that the light entering the object scatters multiple times before exiting the object.
Single-scattering has strong directivity, and the effect is very sensitive to the relative positions of the object, lights, and the camera. Conversely, multi-scattering has very diffuse lighting effects, since the light that enters the object is reflected many times before leaving the object.
Translucency
You can set the Translucency eitehr as a relative value or as an absolute value. The relative Translucency is a value relative to the longest side of the object’s bounding rectangle (set to 1.0). <leave as is - K to get clarity> Setting a relative Translucency value for objects such as a sphere in which the width and height are equal is not problematic, but sometimes it is easier to use an absolute Translucency value for objects with very different widths and thicknesses. In this case, be sure to set the absolute Translucency to a value that does not exceed the object’s thickness. (The absolute value is measured in world coordinates.) If the object becomes speckled or otherwise looks odd, verify that the absolute Translucency value is less than the object’s thickness.
The Translucency of the object can be set separately for each RGB color by specifying the color in the color box, but the translucency calculation will go faster if each RGB value is the same (i.e., the color is set to white).
Single-Scattering
Here you can set the single-scattering factor.
From the left, the Single-scattering value is set to 1.0, 2.0, 3.0, and 4.0.
Multi-Scattering
Here you can set the multi-scattering factor.
From the left, the Multi-scattering value is set to 2.0, 4.0, 6.0, and 8.0.
Single-scattering Samples
Here you can set the number of samples to be run of the light entering the object from the shading point, for single-scattering calculations. Sampling for multi-scattering is calculated automatically from the Translucency value.
Sample Relaxation
During multi-scattering calculations a number of sample points on the object’s surface are chosen at random. In order to make the spacing between sample points as uniform as possible, the sample points are rearranged a number of times, in accordance with the specified Sample Relaxation value. Increasing this value will result in higher quality surfaces, but will also increase pre-rendering processing time. If the rendered image looks hazy, you may need to increase the Sample Relaxation value.
Aberration
When the Translucency value is greater than zero, you can express a color aberration by modifying the refractive index for each of the RGB colors.
Use Shade Parameters
When this checkbox is on, the Aberration value in the Surface window is used. For more on the Aberration value, see “Aberration Slider and Text Box” in the Shade 8 User Guide, “Chapter 13: Setting Surface Attributes”.
If you uncheck the “Use Shade Parameters” checkbox, you can adjust the color aberration manually by adjusting the R, G and B sliders. The values set here for R, G and B are added to the corresponding refractive index.
The above image was rendered using the following Aberration values:
R: 1.4; G: 1.65; B: 1.9
Mapping
CALLISTO comes with a Displacement Map that is not provided in the Shade standard renderers, and a function to individually specify the filtering of the Image map.
The Mapping panel of the CALLISTO Material window allows you to specify these functions.
Create Custom Attribute / Delete Custom Attribute
When the selected object has surface attributes settings, click the Create custom attribute button with the Texture Layer active. This allows you to specify the CALLISTO Mapping information for the currently selected texture layer. Clicking the Delete custom attribute button will delete the custom attributes. Note that the CALLISTO Mapping information cannot be recovered once it is deleted.
Offset R / G / B
This parameter allows you to specify the amount of Offset for each RGB channel of the selected texture pattern.
The Offset value can be specified for each RGB channel. The actual value can be obtained by adding the Offset value to the pixel value, and multiplying the result by the Mapping value.
This image was rendered by multiplying the gray pattern by the Offsets.
Filter X / Y
You can specify the anti-aliasing Mapping filtering for each texture layer.
In the Shade Rendering options dialog, when Antialiasing is turned off, these values will be ignored.
Note: Refer to the description of the Filter size parameter in the Rendering options for details on these parameters.
Displacement Mapping
When Bump mapping is specified for the Texture Layer, you can turn the Displacement checkbox on to perform Displacement mapping, which displaces the object surface in the normal direction when rendering with CALLISTO.
Type the amount of displacement directly into the Bump Mapping parameter in the Shade Surface window.
Photon Mapping Overview
Calculating Indirect Light with Photon Mapping
CALLISTO uses Photon mapping when simulating Global Illumination.
To explain the Photon mapping algorithm simply, any part in the scene on which light emitted from a source will impinge (as a result of repeated reflections or refractions, in some cases) is recorded in advance, and the recorded result will be added to the brightness of any visible object when rendering.
Light emitted from a light source is expressed as a group of particles with a certain intensity, called “photons,” which is radiated using calculations including Ray Tracing.
In CALLISTO, the photons are stored in an “illuminance.” The illuminance is of finite size in a scene, and as a parameter, it has an Illuminance sample width that determines the precision of the Photon mapping and an Illuminance filter type and Illuminance filter size that are used to specify the filtering method for rendering.
Note: For details on how to specify these parameters, refer to the description of the Shape > Illuminance information in the CALLISTO Information window.
CALLISTO Renderer Photon Mapping Calculation
To perform the Photon mapping calculation with CALLISTO, some requirements must be met.
First, in the CALLISTO Information window, the Use photon map checkbox of the Rendering options must be turned on.
Next, also in the CALLISTO Information window, when Photon map calculation in the Rendering options is set to always, the Photon mapping calculation is ready to start. If the calculation is not to be performed, the renderer determines whether the existing photon map can be used or not. Naturally, the Photon map must be calculated at least once.
If a photon map exists, the rendering with Photon mapping will start at once.
When calculating the photon map, the program will check for an “illuminance” that stores the calculated photons, and will create a “default illuminance” when no illuminance exists in the scene.
CALLISTO will consume memory when initializing the illuminance. If the range of the illuminance is extremely large for the sample width, or if a large number of objects are located in the scene, a huge amount of memory may be consumed.
Once the illuminance has been initialized, photons are radiated from the light sources.
This is the most time-consuming process in rendering with Photon mapping. This calculation does not increase the memory consumption.
Once photons coming from all light sources that radiate them have been calculated, the photon map is saved. You can choose where to save it by selecting the Save photons in custom attributes checkbox of the Rendering options in the CALLISTO Information window.
When this checkbox is on, the photon map will be saved in the custom information of the Shade file. With the checkbox off, a temporary file is used.
Once the photon map is saved, the rendering starts, and includes the indirect light and caustics that were calculated with Photon mapping.
Blending Surface Attributes Using the Compo Joint
CALLISTO can blend surface attributes using a Compo Joint. The Compo Joint allows you to create an object made of a mixture of totally different materials, or an animation in which the material itself changes, which were quite difficult to achieve in previous versions of Shade.
Creating Compo Joints
A Compo Joint is created by choosing CALLISTO Compo Joint from the Part tool in the Toolbox.
The settings for the Compo Joint are made in Surface composite type and Composite factor attenuation in the Shape information of the CALLISTO Information window.
Every object contained in the Compo Joint must have its own surface attribute settings. The surface attributes of the Compo Joint are a composite made by blending the results of the brightness calculation for each surface attribute using a user-specified method. You can choose from none, under, over, or plus for the Surface composite type in the Shape information of the CALLISTO Information window, to specify the method used to blend the surface attributes using the Compo Joint.
Note: No synthesis is performed. Rendered as usual. Under: Alpha-blend is carried out from the top of the Browser.
Over: Alpha-blend is carried out from the bottom of the Browser. When you set this for the Compo Joint at the top, only the material of the original object is rendered.
Plus: The brightness value multiplied by the composite ratio is simply added. The composite ratio of the surface attributes is specified by the joint value of the Compo Joint.
Compo Joints can be nested: that is, if a child of a Compo Joint is also a Compo Joint, the blended result of the grandchild is used as a surface attribute of the child. If a Compo Joint has a child, the surface attribute set for the parent Compo Joint will be ignored. However, if the first layer of mapping is specified, the Red channel of that mapping is used as a composite ratio instead of the joint value.
When a child of the Compo Joint is a Link, the surface attribute to be used belongs to the original object to be linked.
Blending Materials
Create a sphere and two Compo Joints to make a parent-child relationship as shown below.
Set a surface attribute for the sphere and CALLISTOCompo: B. In this example, red is applied to the sphere and green is applied to CALLISTO-Compo: B.
Even if you are just setting the basic color, click the Create button to create a surface attribute set. The materials cannot be blended with the Compo Joint if no surface attributes are created.
When changing the joint value of the Compo Joint to which the red material is applied, the green and red materials are blended in the rendering.
Joint value: 0.1
Joint value: 0.5
Joint value: 0.9
Using a joint allows you to change the material in an animation.
Nested Compo Joints
When a Compo Joint is located inside another Compo Joint, the parent Compo Joint inherits the result of the synthesis carried out for the child Compo Joint.
The result of the synthesis of Compo A and Compo B becomes the material of the parent Compo Joint, which is blended with the surface attributes of the sphere.
Synthesis Using Mapping
The first layer of the mapping is used as a mask for the synthesis. The second and later layers of mapping or other parameters are ignored. When you use a mapping (except an image used as a composite ratio), set the mapping color to other than black. If the color of the mapping pattern is black, nothing is synthesized. It is recommended that the base color be set to black and the mapping color to white.
The composite of A and B is blended with the material of the sphere, using the marble pattern as a mask.
Composition Using Attenuation with Angle
In the CALLISTO Shape information > Material composite panel, change the Composite factor attenuation so that the degree of synthesis will depend on the angle of view.
If you set Composite factor attenuation 0 to 0.0, the composite ratio of the Compo Joints is decreased at the front of the object (as viewed from the camera).
Sample Objects Using Compo Joints
Several sample objects that use Compo Joints are included the “Documentation - Sample” folder in ShadeExplorer.
CALLISTO_sample1.shd
CALLISTO_sample2.shd
CALLISTO_sample3.shd
Surface Attribute Percentages of Compo Joints
The percent value of surface attributes can be set between 0 and 1 using Compo Joints.
Here we will use “CALLISTO_sample2.shd” sample file to demonstrate this.
1. Open the Motion window by choosing View > Motion, and/or open the Object Info window by choosing View > Object Info.
2. Select the “CALLISTO-Compo: :CALLISTO Shape” part in the Browser.
3. In the Motion window you can adjust the Compo Joint value by moving the vertical slider. In the Object Info window, move the Joint slider. Try rendering with different joint values.
Compo Joint set to 1.0
Compo Joint set to 0.5
Compo Joint set to 0.2
Compo Joint set to 0
If the Compo Joint has mapping applied, be careful not to set the Joint value to 0 or the mapping will appear black.
CALLISTO and Shade Renderer Differences
Surface Attribute Relationships
Bump Mapping for UV Mapping
CALLISTO allows you to render the Bump mapping applied to the UV mapping of a polygon mesh.
Front and Back Sides of Object
In CALLISTO the front and back sides of an object are strictly interpreted, and objects for which Refraction is set will be rendered differently than with the Shade renderers.
Mapping by Distance
The Adaptive surface tessellation function does not support mapping by distance. Also, mapping by parameter has a different interpolation and the location to be mapped is not exactly the same as with the Shade renderers. If you want to exactly align the Wrap mapping with a Shade rendered image, turn off the Adaptive surface tessellation checkbox in the Rendering options or in the Shape information.
Mixing of Distance Mapping and Parameter Mapping
When mapping by distance and mapping by parameter are mixed in a single surface attribute, it will not be properly rendered.
Specular Color
Specular 1 and Specular 2 must be the same color. If the value of Specular 1 is larger than zero, the color of Specular 2 is set to the color specified in Specular 1. If the value of Specular 1 is zero, the color of Specular 2 is enabled.
Metallicity
Unlike the Environment mapping in Shade, Metallicity simulates a metallic specular surface. As the Metallicity value becomes larger, the specular color changes from the color of the light source to the color of the material.
Highlight Effect
The Highlight effect is slightly brighter in Shade than in CALLISTO when the same value is specified.
Bump Mapping
The Bump mapping is bumpier in Shade than in CALLISTO when the same value is specified. When Marble, Cloud, Wave, or Ocean is used as a Bump mapping, the bumps are finer in CALLISTO than in Shade.
Solid Texture Plugin
Plugin-specific mappings (Grid, Bump Array, Brick, Blob, Beehive, Sand, Veins, Triangle Check, Gradation, and fBm) are not supported by CALLISTO.
Expressing the Transmitted Image
When Transparency is set to other than zero, the formula to obtain apparent brightness using the original brightness and the brightness of the transmitted object is different between CALLISTO and Shade. For normal settings, the rendered image is brighter in Shade in most cases.
Linking Transparency and Other Parameters
In the default state of CALLISTO, in order to reproduce light energy conservation, Diffuse and Emission will be weakened as Transparency is increased.
In the CALLISTO Material window when the Link attributes with opacity checkbox is turned off, Transparency, Diffuse, and Emission can be set independently, just as with Shade.
No Shading
No Shading (in the More Surface Attributes window from the More button of the Shade Surface window) is not supported.
Black Key Mask and White Key Mask
Black Key Mask and White Key Mask are not supported. By using Compo joints, similar effects can be obtained.
Pseudo Caustics and Aberration
Pseudo Caustics and Aberration are not supported.
Wrap Mapping for Disks
Wrap mapping for Disks is not supported. Wrap mapping will be enabled for a Disk converted to a Curved Surface.
Specular Mapping
CALLISTO does not distinguish between Specular 1 and Specular 2 in Specular mapping.
Definition of Environment Mapping
When both Environment mapping and Reflection are used, the environment and the reflection of an object are blended in Shade, while the reflection of the object is located in front in CALLISTO.
Soft Glow
Soft Glow is not supported. By specifying Emission Parameter attenuation in the CALLISTO Material window, a similar effect can be obtained.
Overlaid Trim Mapping and Displacement Mapping
Multiple Trim mappings or multiple Displacement mappings cannot be overlaid. Only the mapping with the largest Mapping layer number is enabled.
Mat Mapping
Mat mapping is not supported. By using Compo joints, a similar effect can be obtained.
Object Relationships
Holes
Holes are rendered differently with Shade standard renderers, and thus the results are slightly different. If a Hole and the outline intersect, or if Holes intersect with each other, the Holes may be ignored.
Special Boolean Rendering Character “&”
Among the Boolean-related special characters, if multiple characters other than “&” are specified for a single object, the result of the rendering may be different from that of Shade.
Boolean Rendering for Flat Object
Because of differences in the algorithm for Boolean rendering, when a plate without thickness exists on the sight line, it may be rendered differently by Shade and CALLISTO.
On the contrary, with Boolean rendering for thick objects, unlike with the Shade standard renderers, it works completely without being affected by the camera position, which allows you to perform Flythru into a tunnel hollowed out with the “*” character.
Native MetaRenderer
Meta objects cannot be rendered with the Native MetaRenderer.
Sides of Surfaces
Both sides of surfaces are always rendered.
Morph Joints and Curved Surfaces
In Morph joints, the vertices of curved surfaces to which Adaptive surface tessellation is applied will not be interpolated. When you want to interpolate a curved surface object, turn off Adaptive surface tessellation in the Rendering options or in the Shape information.
Morph Joints and Displacement Mapping / Trim Mapping
When you specify Displacement mapping or Trim mapping for objects contained in a Morph joint, the surface attribute will not be interpolated properly.
Links
When an original object to be linked to is not the target to be rendered, the Link is not rendered. The Link will be rendered only when both the Link itself and the original object are rendered.
Light Relationships
Point Lights and Spot Lights
Specular and Diffuse parameters for Point lights / Spotlights are not supported.
Irradiation Angle of Spotlight
The angle of irradiation for Spotlights is limited to within 180 degrees. In Shade, even if the angle is set to 180 degrees or less, the light will spread at an angle exceeding 180 degrees due to the Softness setting. In CALLISTO, the angle will never exceed 180 degrees.
Softness of Spotlights
Softness of Spotlights is supported, but its blurring differs from that of the Shade standard renderers.
Area Lights
Area lights of Closed line objects are supported only for Rectangles. To use a Closed line object other than a Rectangle as an Area light, it must be specified as an object light.
Distant Lights
Specular, Diffuse, Glare, Size, and Skylight specified in the Distant Light window are not supported.
The value of Fog is supported, but its color is not available and stays close to the color of the background at all times.
By using CALLISTO SkyLight, you can make more flexible settings for sky lights than you can in Shade.
For more information, refer to “Light information”, “Setting sky light”, and “sky light types in the CALLISTO Information window section in the CALLISTO Reference.
Photon Mapping and Attenuation of Light Sources
When Photon mapping is applied to Point lights and Spotlights, the attenuation is always Quadratic, regardless of the dialog setting.
Distribution Light Data
Distribution Light data is not supported.
Camera Relationships
Camera Parameters
The following camera parameters are not supported by CALLISTO: Shift, Rise, Film swing, Film tilt, Lens swing, and Lens tilt.
Bank and Correction
When both Bank and Correction are set to other than zero, the rendered image will be distorted.
Fish-eye Distortion
Fish-eye distortion is not supported.
Depth of Field
Camera Depth of field is not supported.
Distortion of Camera Objects
When a Camera object is unevenly scaled up or down, the rendering result may differ greatly.
Other
Background
For the background textures, only Haze is supported when it is set as the first layer.
When the color is different for the upper and lower hemispheres, areas around the horizon line may appear unnatural. In this case, specify the same color for Haze for both hemispheres.
To show a background similar to that of Shade, the Background Helper plug-in contained in CALLISTO must be used. For more information, refer to “Background Helper plug-in” in the Shade Reference.
Sideways
The Sideways checkbox is not supported.
Radiosity
Radiosity is not supported.
Direction of Image
When the Pixel Aspect Ratio is negative, the result will differ from that of Shade.
Premultiplied Alpha
Same as with Misc. / Premultiplied alpha - always on in the Rendering options.
Transparency Affects Alpha
Same as with Misc. / Transparency affects alpha - always on in the Rendering Options.
Render Transparency
The Render Transparency checkbox is not supported.
Compatibility in Rendering
Compatibility in the Rendering Options is not supported. |
