Shade 9 Chapter 1 An Introduction to 3D Computer Graphics

Although your computer monitor may be a flat two-dimensional surface, objects can be represented in three dimensions using several techniques. Computer software that uses this technology is called 3D computer graphics software. Shade is one of those “3D CG” software applications.

What are 3D Computer Graphics?

What’s the difference between 2D (two dimensional) and 3D (three dimensional) graphics? 2D graphics are flat images such as a painting on a canvas or a piece of paper. 3D graphics have a width, height and depth (along the X, Y and Z axes) and can be moved, rotated and manipulated in three dimensional space like real objects can be manipulated in real life. 2D software also differs from 3D software.

Let’s take a look at an image created in 2D and one created in 3D:

2D image

3D image

The below image looks like it has real depth, an effect made possible through the use of 3D computer software.

General Workflow in 3D Computer Software

Let’s take a look at the general steps usually followed when creating a scene using 3D computer software such as Shade:

1. Modeling (Building Objects)

The first step in creating a scene is to design and build the objects (such as people, animals, buildings, trees and almost anything else) you want to have in the scene. The concept is the same as building plastic models. You start by building smaller pieces, and eventually assemble the finished model by putting all the individual parts together.

2. Texturing

Once your models are built, the next step is to apply the appropriate colors, textures, patterns and transparency to each object.

3. Lighting

Not only are studio lighting effects possible in 3D computer graphics, but natural lighting from the sun or sky can be simulated as well. You can set up one or multiple light sources, adjust the luminosity of each light, change the amount of ambient light in the scene and much more.

4. Camera Positioning

Choosing the camera angle is important in communicating the feeling and impression you wish to express to your audience.

5. Rendering

Rendering is the process of transforming the work you did in all the steps up to this point into a picture, either an image to check the results of your work in progress or the final image that you will publish to print or the Web.

In Shade, objects can also be animated. If you wish to create an animation you’ll need to setup joints along which the objects can move and then edit the animation along a timeline. The final step will still be rendering, but the result will be a movie instead of a still image.

Characteristics of Shade

The Structure of Curved Surfaces

Shade makes strong use of Bezier curves for modeling objects. These “curved surfaces” are formed of one or more sectional lines running in the horizontal and vertical directions. By editing the shape of these lines, either individually or in groups, we can create the shape of a complex, yet smooth, surface.

The above object is composed of a series of elliptical lines running longitudinally from the fish’s head to its tail, and a series of laterial lines running along its sides, dorsal and ventral surfaces. Surfaces are drawn across the points where the lateral and longitudinal lines intersect. Imagine an umbrella or paper lantern. The flexible material is stretched over the underlying skeleton to form a shape in a similar way that curved surfaces in Shade work. |