Chapter 9 Other Object Types

From ShadeCamp

A MetaMesh is a kind of polygon mesh automatically generated by synthesizing Meta-elements. There are four different types of Meta-elements: the spherical MetaBall, cubic MetaCube, cylindrical MetaCylinder, and MetaPolygons converted from any polygon mesh. You can combine Meta-elements, and Meta-elements inside the same part, and they will fuse together smoothly. You can edit or move a created Meta-element or change its parameters to change the shape of the MetaMesh. MetaMeshes can be rendered normally; however, if you use the Native Meta Renderer which performs a fusion calculation for Meta-elements during the Ray Tracing calculation process, higher-quality rendering can be obtained. You can also merge surface attributes that are specified for a Meta-element when you use the Native Meta Renderer. Animations can be created by applying movements to joints of a Meta-element. Shade 9 can display generated MetaMesh shapes in real-time according to the result of edited Meta-elements in Modify mode, to improve ease-of-use.

Types of Meta-Elements

There are four different types of Meta-elements as described earlier. The type of Meta-element can be seen from the name displayed in the Browser window.

There are four types: spherical MetaBalls, cubic MetaCubes, cylindrical MetaCylinders, each created using the Create tool in the Toolbox; and MetaPolygons created by transforming Polygon Meshes using the Modify tool. These can be mixed. The shape of a Metaelement can be identified from the name displayed in the Browser window: MetaBall is “Ball”, MetaCube is “Cube”, MetaCylinder is “Cylinder”, and MetaPolygon is “Polyhedron”.

Now, let’s create Meta-elements and check the differences and names in the Browser window.

MetaBall Elements

MetaBall elements are created just like a sphere. Choose MetaBall from the Create tool, and drag the mouse cursor from the center of the Meta-element to a point on the circumference. The point where the mouse button is released is entered as the radius, and a MetaBall element is created. When a MetaBall element is created, a MetaMesh is also created at the same time. A sphere showing the fusion area of the MetaBall element is displayed outside of the MetaBall element on the Figure window.

The Browser window will show the MetaBall element as “MetaBall :+BlobBall”, “MetaBall :-BlobBall”, “MetaBall :+MetaBall”, or “MetaBall :-MetaBall”. A MetaMesh is displayed as “MetaMesh : MetaMesh” or “MetaMesh :Native-Meta”.

When there are other Meta-elements, they are merged into a MetaMesh.

MetaBall elements are created just like a sphere. The MetaBall element can be

d or rotated by dragging the four corner points and moved by dragging the center point.

While editing by dragging the points in the Modify mode, the change in the edited MetaMesh shape is displayed in real-time. When there are Meta-elements within the fusion area, the result of a merged MetaMesh is also displayed in real-time, to allow you to see what is going on as you work.

This enables you to easily edit a MetaMesh. Of course, other types of Meta-elements can also be observed during editing.

MetaCube Elements

Choose MetaCube from the Create tool in the Toolbox, then drag the mouse cursor in the Figure window, just as in entering the distance of the vertex of a surface of the MetaCube element. Dragging the mouse cursor while pressing the 4 restricts the direction of the 3D cursor just as in creating a rectangle, thereby facilitating the creation of a cube. The position where you released the mouse button is entered as the other end of the vertex, and a MetaCube element is created. The height of the MetaCube element is equivalent to the length of the longer side of the surface that you have just created. When a MetaCube element is created, a MetaMesh is also created. A cube showing the fusion area of the MetaCube element is displayed outside of the MetaCube element in the Figure window.

The Browser window will show the MetaCube element as “MetaCube :+BlobCube”, “MetaBall :- BlobCube”, “MetaCube :+MetaCube”, or “MetaCube :-MetaCube”. MetaMesh is displayed as “MetaMesh : MetaMesh” or “MetaMesh :Native-Meta”.

When there are other Meta-elements, they are merged into a MetaMesh.

A MetaCube element consists of eight points. You can scale the element by dragging four corner points. Editing the MetaCube element along the X axis scales it proportionally in the Y- and Z-axis directions, editing it along the Y axis does the same in the X- and Z-axis directions, and editing it along the Z axis does the same in the X- and Y-axis directions.

MetaCylinder Elements

Choose MetaCylinder from the Create tool, and drag the mouse cursor from one end of the MetaCylinder element to the other, just as when entering a length.

Dragging the mouse cursor while pressing the Shift restricts the direction of the 3D cursor just as in creating a rectangle, thereby facilitating the entering of horizontal and vertical lengths.

The position where you released the mouse button is entered as the other end of the straight line, and a MetaCylinder element is created. The diameter of a MetaCylinder element is automatically adjusted in accordance with the entered length. When a MetaCylinder element is created, a MetaMesh is also created. A cylinder showing the fusion area of the MetaCylinder element is displayed outside of the MetaCylinder element in the Figure window.

The Browser window will show the MetaCylinder element as “MetaCylinder :+BlobCylinder”, “MetaCylinder :-BlobCylinder”, “MetaCylinder :+MetaCylinder”, or “MetaCylinder :- MetaCylinder”. The MetaMesh is displayed as “MetaMesh : MetaMesh” or “MetaMesh :Native-Meta”.

For MetaCylinder elements, the sectional surface disk of a MetaCylinder can be edited. Just like an ordinary disk, the MetaCylinder element can be scaled or rotated by dragging the four corner points and moved by dragging the center point.

MetaPolygon Elements

MetaPolygon elements are generated by transforming Polygon Meshes into Meta-elements.

When you select a Polygon Mesh and choose Convert to MetaPolygon from the Modify tool, the Convert to MetaPolygon dialog box appears. After setting the MetaMesh type, Meta volume, and Size of (Blob/Meta) Polygon, and pressing OK, a MetaPolygon element is created.

For details on the Convert to MetaPolygon dialog box, refer to the Shade Reference.

At the same time the MetaPolygon element is created, a MetaMesh is created outside the selected MetaPolygon element, with the thickness set in the Size of (Blob/Meta) Polygon item. A shape showing the fusion area of the MetaPolygon element is displayed outside of the MetaPolygon element in the Figure window. If the original Polygon Mesh is open like a plate, then the MetaMesh is generated toward the direction of the normal line.

The Browser window will show the MetaPolygon element as “PolygonMesh :+BlobPolyhedron”, “PolygonMesh :-BlobPolyhedron”, “PolygonMesh :+MetaPolyhedron”, or “PolygonMesh :-MetaPolyhedron”. The MetaMesh is displayed as “MetaMesh :MetaMesh” or “MetaMesh : Native-Meta”.

For a MetaPolygon element, the vertex of the transformed PolygonMesh is displayed as a point. The MetaPolygon element can be edited by dragging this point, just as for a PolygonMesh.

Merging Meta-Elements

Meta-elements will merge when they are brought close together. When they are moved apart, they will separate.

Fusion Area of Meta-Elements

The Fusion area of Meta-elements, that is, the distance at which fusion with other Meta-elements starts to take place, is displayed outside the Meta-element as a wireframe. When objects inside Meta-elements intersect within the respective fusion area, each Meta-element merges with the other Meta-elements within its own fusion area. The fusion area can be set in the Properties (Meta-element Settings) dialog box displayed by selecting Set MetaMesh Attributes in the custom tool with the Meta-element selected.

Top: Fusionable scale is set to 2.0, the default value.

Bottom: Fusionable scale is set to 1.2.

Subject of Meta-Element Fusion

Meta-elements fuse with other Meta-elements located in the part where the first Meta-element was created, or with other Meta-elements located in a joint included in the part where the first Meta-element was created. A Meta-element included in a part included in the part where the first Meta-element was created will be ignored. Refer to the “Hierarchical structure of a meta group” for more details.

Recalculation of Meta-Element Fusion

When a certain operation has been performed on a Meta-element in the Figure window, the recalculation of fusion is executed automatically. Using the Browser window, keyboard, or any dialog box to perform certain actions related to Meta-elements or fusion of Meta-elements will not perform the recalculation automatically. In this case, select a Meta-element and click the Figure window while holding down the Shift + X keys (Win) / Shift + Command keys (Mac) to recalculate fusion. Some of the most frequently used operations for each case are described below:

Operations which require no recalculation:

-Creating, moving, copying, or deleting Meta-elements in the Figure window.

-Operations which require recalculation:

- Changing parameters in the Sphere dialog box, Polygon Mesh dialog box, or Extruded Disk dialog box.

- Canceling deletion of a Meta-element.

In order to carry out recalculation, a Meta-element, an object, or a part located in the previous or next hierarchy of a Meta-element must be selected directly.

Meta-Element Fusion Calculation

There are two techniques for the fusion calculation: Meta type and Blob type. The former method realizes smoother fusion than the latter, but requires more time for calculation. You can set the type of calculation to be used when creating a MetaMesh, and also change the Meta-element type after a Meta-element is created. The calculation method can be identified by the name displayed in the Browser window: Meta is indicated as “Meta”, whereas the Blob type is indicated as “Blob”. The fusion calculation technique can be set in the Properties (Meta-element Settings) dialog box displayed by selecting Set MetaMesh Attribute from the custom tool with the Meta-element selected.

Meta-Element Fusion

There are two methods used for this calculation: fusion and reverse-fusion. The latter method fuses by trimming other Meta-elements. The fusion calculation method can be identified from the name displayed in the Browser window: fusion has the character “+”, whereas reverse-fusion has the character “-“ attached. The fusion calculation can be set in the Properties (Meta-element Settings) dialog box displayed by selecting Set MetaMesh Attribute from the custom tool with the Meta-element selected.

Top: Regular fusion Bottom: Inverse-fusion

For example, when the type of a Meta-element is a MetaBall element, and if you are using the Blob type fusion calculation technique, then the Metaelement name would be “MetaBall :+BlobBall”, and this name is displayed in the Browser window. The part of the Meta-element name after the colon ( : ) cannot be changed.

Meta-Element Settings

When selecting Set MetaMesh Attribute from the custom tool in the Toolbox with a Meta-element selected, the Meta-element Settings dialog box appears. This dialog box allows you to set the fusion method or fusion area for the Meta-element.

Polarity of Meta-Volume Pull-down Menu

Sets regular fusion or reverse-fusion of Meta-elements. Fusion and reverse-fusion are respectively represented as “+” and “-“.

Meta-Element Type Pull-down Menu

Sets the type: Blob or Meta.

Fusionable Scale Text Box

Enter a scale factor to set the fusion area.

When selecting Set MetaMesh Attribute from the custom tool in the Toolbox with the MetaMesh selected, the MetaMesh Settings dialog box appears.

MetaMeshes

A MetaMesh is automatically created below the parent part closest to the Meta-element when a Meta-element is created. When multiple Metaelements are created, the shape of the MetaMesh is the result of the fusion of those Meta-elements. The shape of a MetaMesh will change when the Meta-elements are moved, or when their parameters are changed. MetaMeshes are treated as Polygon Meshes. When you use the Native Meta Renderer, the status of MetaMeshes in the Figure window can serve as visual aids for the rendering result. A MetaMesh is displayed as “MetaMesh :MetaMesh” in the Browser. The MetaMesh name after the colon ( : ) cannot be changed.

Shapes of MetaMeshes

Shapes of MetaMeshes are determined by the way in which Meta-elements are merged. Every time the way in which the merger of the Meta-elements takes place changes, Meta-elements are recalculated, resulting in the changes in shapes. Recalculation of MetaMeshes might be required in order to confirm the shape of MetaMeshes, when Meta-elements have undergone parameter changes, been copied or deleted, or when the hierarchical structure of the meta groups has changed.

MetaMesh Quality

Other than determining the Meta-element fusion calculation technique, MetaMesh quality can be set using the MetaMesh mesh size. The lower the MetaMesh mesh size, the smoother the fusion, but the longer the time required for calculation. When you are using the Native Meta Renderer, the differences in the Meta-element calculation technique will be reflected, though the MetaMesh mesh size will not be reflected. The MetaMesh mesh size can be set in the MetaMesh Settings dialog box displayed by selecting Set MetaMesh Attribute from the custom tool.

Low mesh size

High mesh size

Editing MetaMeshes

Because MetaMeshes can be treated as Polygon Meshes, they can be separately moved to other parts, or can be edited and transformed just like regular Polygon Meshes, after they have been transformed into Polygon Meshes. Editing a MetaMesh without fixing or transforming it into a Polygon Mesh will result in the recalculation of the MetaMesh, and any previous editing of the MetaMesh will be cancelled.

Note: When editing MetaMeshes using the Skin setting function, include “MetaMesh :MetaMesh” of the Browser in a new part so that the MetaMeshes will not be affected by the Meta-elements.

Evacuating MetaMeshes and Transforming MetaMeshes into Polygon Meshes

In order to edit MetaMeshes, they need to be evacuated as MetaMeshes or transformed into Polygon Meshes. This method is useful to avoid unexpected recalculation of MetaMeshes resulting from moving Meta-elements mistakenly. A MetaMesh can be fixed by moving it into a part other than the part where it was generated. The MetaMesh which has been fixed will not be affected by modifications on Meta-elements. Clicking a MetaMesh while holding down the Shift + X key (Win) / Shift + }{ (Mac) after evacuating the MetaMesh will generate a new MetaMesh in the part where the Meta-elements are located. In order to carry out this operation, a Meta-element, an object, or a part located in the previous or next hierarchy of the Meta-element must be selected directly.

A MetaMesh can be automatically transformed into a Polygon Mesh by duplicating the MetaMesh using the Copy tool or by clicking convert in the Toolbox. Once convert is clicked, the MetaMesh is transformed into a group of closed line objects enclosed in one part. Selecting the part containing a group of the line objects and clicking convert again will transform the MetaMesh into a Polygon Mesh.

Regenerating MetaMeshes

MetaMeshes are regenerated by moving a MetaMesh or a Meta-element to another part and then clicking the Figure window while holding down the Shift + X key (Win) / Shift + }{ (Mac).

By moving a MetaMesh to another part, a fusion

calculation for the remaining Meta-element will be executed in the part where that MetaMesh had been located, and a new MetaMesh generated. The first half of the operation is equivalent to evacuating the MetaMesh.

By moving a Meta-element to another part, a fusion

calculation for the Meta-element which has been moved will be executed in that part, and a new MetaMesh generated. A fusion calculation will be executed for the Meta-elements that remain in the former part. In order to carry out the regeneration, a Meta-element, an object, or a part located in the brother hierarchy of thee Meta-element must be selected directly.

Dividing MetaMeshes

MetaMeshes are divided in accordance with the global coordinate system.

MetaMesh Settings

When selecting Set MetaMesh Attribute from the custom tool in the Toolbox with a MetaMesh selected, the MetaMesh Settings dialog box appears. This dialog box allows you to set the size of the MetaMesh. When selecting Set MetaMesh Attribute from the custom tool in the Toolbox with a Meta-element selected, the Meta-element Settings dialog box appears.

Mesh Size Text Box

Sets the mesh size of a MetaMesh.

The lower the number, the more minute the mesh.

The default value is 2.0.

Realtime Mesh Scale Text Box

Represents the scale factor for the original size to easily display a MetaMesh in the Modify mode.

The default value is 2.0.

Display Mode Pull-down Menu

Select a display mode for the MetaMesh from Mesh and Basic Shape.

Display Mode is set to Mesh.

Display Mode is set to Skeleton Solid.

Other Operations on Meta Objects

Hierarchical Structure of a Meta Group

MetaMeshes are created below the parent part where a Meta-element was created. They are fused every time Meta-elements are created in that part, or in joints included in that part. When Meta-elements are changed, the shape of the MetaMesh will also change. The part where the Meta-element is created is called a “meta group.”

If there are Meta-elements in a part included in a meta group, then that part also contains MetaMeshes, or that MetaMesh is regenerated. A part included in a meta group will be the second meta group. It is possible to control the movement of a MetaMesh or another MetaMesh which follows the movement of that MetaMesh.

In the Browser below, MetaMesh A consists of MetaBall 1 and 2 only.

In other words, the range of a Meta group is controlled by the part.

Rendering the Result of Meta-Element Fusion

MetaMeshes resulting from fusing Meta-elements can be rendered by applying surface attribute settings as Polygon Meshes. If you are rendering with the Ray Tracing or Path Tracing method, the fusion of Metaelements will be calculated during the Ray Tracing calculation when using the Native MetaRenderer, and high quality rendering will be possible; it is also possible to fuse surface attributes of Metaelements. Select a MetaMesh and choose Native MetaRenderer Attribute from the custom tool. The Native MetaRenderer dialog box opens. Turn on the Apply Native MetaRenderer checkbox.

When the Native MetaRenderer is applied, the name of the MetaMesh in the Browser window is changed into “MetaMesh :Native-Meta,” thus allowing you to check whether the Native MetaRenderer will be applied. The name for the case where the Native MetaRenderer is not applied is “MetaMesh :MetaMesh.”

Note: When rendering a Polygon Mesh where concave and convex areas are adjoined, the rendered image may appear with the edge part not clear, but as a shadow.

The Native MetaRenderer will be explained in the next section by showing the actual operation.

Boolean Settings

You can use a MetaMesh for Boolean operations. It is possible to use the Native MetaRenderer in Boolean rendering. In Boolean rendering, the MetaMesh is the subject of a Boolean operation, and surface attributes of Meta-elements will be ignored. When executing Boolean modeling, surface subdivision need not be set.

Result of rendering a Boolean operation with the Native MetaRenderer.

Exporting Results of Meta-Element Fusion

A MetaMesh will be exported as a Polygon Mesh. When exporting, surface subdivision need not be set.

Native MetaRenderer

If you set the Native MetaRenderer for any MetaMesh, you can get smoothly rendered images in which the Meta-elements are fused and not affected by the resolution of the MetaMesh. In addition, you can also get rendered images in which the surface attribute settings of each Meta-element are visible.

1. Select each MetaBall and give them different diffuse colors.

2. Select the MetaMesh and choose Set Native MetaRenderer Attribute from custom in the Toolbox. Check the state of the Apply Native MetaRenderer checkbox in the Native MetaRenderer dialog box. If the Apply Native MetaRenderer checkbox is turned off, switch it on.

The Native MetaRenderer is applied to the MetaMesh. This can be confirmed by the object name in the Browser window.

3. After displaying the Image window, open the Rendering Options, choose Ray tracing from the Rendering Method pull-down menu, and render.

The Native MetaRenderer setting is only effective if you use Ray Tracing or Distribution Ray Tracing.

The rendered image

Here we have used MetaBalls, but the same functions will work for MetaMeshes generated from any other Meta-elements. |