Preface Welcome to the World of 3D
From ShadeCamp
If you just started working in the 3DCG (3 Dimensional Computer Graphics) field, as a professional 3d artist or hobbyist, you might be surprised at all the new terms and technical explanations there are. If you have studied basic design, drawing or painting, you probably already experienced a world of descriptions just to talk about art in a 2D space. 3DCG uses all of those terms - and more! Let’s learn the 3DCG terms necessary for learning Shade, and then continue with the basic concepts of 3DCG.
Contents |
What is 3D?
Since you are reading this manual, you've guessed that Shade is 3DCG software, used to create three dimensional computer graphics. However, what Shade finally creates will be images, or animated movies. These are two dimensional images, or animations of two dimensional images. Where does the “three dimensional” aspect come in? And how is it three dimensional? What is the difference between 2DCG and 3DCG software? We will answer these questions by following the work flow of 3DCG software.
And what is work flow? Work flow are the linked steps to achieve any purpose, often using multiple tools and even multiple participants.
With 3DCG software, you begin by entering data for one or more three dimensional solid objects. This work is called modeling. Modeling has to be performed by the user. If you create more complex solid shapes, the modeling operation also becomes more complex and takes more time.
Once you finish modeling, you can create the final two dimensional image (or animation) that is calculated based on the three dimensional data. This computational work is called rendering. In this case, all you have to do is make the desired settings for the rendering, and then tell the computer to proceed. Rendering is performed by the software and the computer. You don’t have to do anything while the rendering is calculated. You can watch the process or take a coffee break.
3DCG software does not draw or process two dimensional images directly. Though the final images you create are two dimensional, the process the 3DCG software goes through is not the same as that for 2DCG software. The 3D aspect of 3DCG software comes from the creation of three dimensional data, making calculations based on that data, and processing a final two dimensional image. 3DCG software thinks out all the calculations for you.
There is a final step which may or may not be necessary, called post processing. This is when you treat your 3DCG images like any other photograph or image and modify it with an image editor.
Elements of 3DCG
First, the solid shape data. Without solid shape data, you would merely get an image of empty space, if you render it. You have to create solid shape data by modeling. Almost all modeling is done by dragging out lines, though some software can automatically generate common shapes like spheres, disks and other geometry forms.
Second, add textures for your solid shapes. Even if a modeled shape is very elaborate, it still needs to be given the proper colors. For example, without color, you could not tell the difference between a white flag, a Japanese flag, and a US flag. Also, you could not differentiate a round watermelon from a basketball if they had no colors or patterns. This explains why it is important to set the proper colors and patterns for your solid shapes. In Shade, these are called Surfaces. Any shapes you don’t specify Surfaces for are rendered as white by Shade.
Third, lay out your composition. Composing your scene is almost exactly like you would if you were taking a photograph, with the exception that you have god-like control over the world you are photographing. In 3DCG, you even have one or more cameras - still cameras and video cameras. In Shade, the position that equates to the camera position is called the “Eye Point.” The position the camera faces, that is, the position right at the center of the perspective view, is called the “Target Point.” Moreover, you can control such values as the lens “zoom” factor or camera “tilt.” The difference between 3DCG cameras and real world cameras is that 3DCG cameras have no sizes, that is, they have no physical limits. You can put an Eye Point in any location because it doesn't take up any real space at all.
Fourth, set up your lighting. These are settings for lights and light sources. In the real world, you can see nothing in the dark. Similarly, if you don’t specify a light source when you render, nothing will be drawn. Shade uses one white “distant light” by default. Other light sources you can use are “point lights,” “spotlights,” “linear lights” and “area lights.” Light sources, like cameras, have no physical limits in the 3DCG world. Light is emitted from a spot where nothing actually exists. Light bounces off of reflective surfaces and passes through translucent surfaces, creating fantastic variations of secondary light in a scene and adding depth and warm to objects.
Fifth, add settings for animation if you are making an animated movie. This is significant only when creating 3DCG animations. Generally, in 3DCG, an animation is created by changing the above four elements over time. In Shade, animation settings for individual shapes are sometimes called “Motion settings.”
The Merits of 3D
Images in 3DCG are indirectly created from solid shape data. Unlike with 2DCG software, you cannot make drawings directly. Modifying an image created with 3DCG software using 2DCG software is called post processing. Chances are, if you use a digital camera, you already do retouching of your photographs on your computer - post processing is the professional term for retouching. You may think creating images in 3DCG is more complicated than 2DCG, and this is true. When can we use 3DCG to get a final and complete image, to great effect? In other words, what are the merits of 3DCG?
3DCG combines the five elements mentioned above. These elements can be changed or modified independently. For example, such operations as changing the colors and patterns of shapes, changing compositions, and changing lighting, are relatively easy. You can modify the result by simply rendering it again with different settings. Though rendering takes a certain amount of time, all you have to do is to push the rendering button. If you want to change the composition of an image drawn using 2DCG software or taken with a digital camera, you have to draw it again from scratch. Retaking a digital photo and getting similar results as your first image can be extremely difficult. With 3DCG, you create the world first, then take a picture.
To achieve the desired result, you render over and over again, and gradually approach the completed image -- that’s the style of production in 3DCG. And you can still go back and tweak it with post processing anyway.
Photo Realism
One of the aims of 3DCG is realism. You may have become interested in using 3DCG when you saw a very realistic 3DCG image or movie. You can draw realistic images using 2DCG programs, but it requires a lot of skill. Does this mean that 3DCG is easy? The answer is no. 3DCG also requires some skill to create realistic images.
As hinted at previously, production process in 3DCG is actually similar to that of photography. When taking a photo, you first prepare the subject, light it, arrange the composition, and release the shutter. In 3DCG, you first prepare the solid shape data, light it, arrange its composition, and render. To make further photos, you reorient the subject and arrange its layout, adjust lighting, change its composition, and release the shutter again.
This is the same production style as in 3DCG. The biggest difference between photography and 3DCG is that the producer (that’s you!) can easily control every element. To shoot an impressive photograph, the photographer has to consider many elements, such as the composition, lighting, shutter timing, and subject. No matter how well he or she does, a photograph will still be created. But will it be a beautiful work of art? It is the same in 3DCG. The producer can freely control all the elements, but the truth of the matter is that the producer must correctly control all the elements together.
Technique and Originality
In the field of computer graphics, the computer is just a tool, and it is still the user who supplies the creativity. 3DCG offers you unprecedented control in five main areas: modeling, textures, camera control, lighting, and animation. Your skills in manipulating these must come together to produce a finished work. Each of these five areas has numerous elements allowing for a wide range of expression. You can learn the basic techniques from manuals, books, magazines, and the Internet. While it is true that techniques are important, more important is what you will express, and how you will express it, using those techniques. A strong desire to create a beautiful 3DCG work can be the greatest motivation to improve your 3DCG skills. Your 3DCG work is a compilation of all of your skill and talent. Learn the techniques and refine your talent and you will no doubt successfully achieve wonderful 3DCG creations. |
