CG Basics - An Introduction to Computer Graphics for Artists - page 29

Fig. 2.24 Light is essential to a render. Without light, a shaded render is impossible

2.6 Conclusion

These are the seven concepts covered in this chapter:

• Coordinate systems

• Interface

• Geometry

• Attributes

• Vectors

• Transformation

• Lights

All computer renderings rely upon these elements. The coordinate system establishes
the space your 3D objects will occupy. The interface allows you to interact with that
space by putting things into it and manipulating them. Geometry is the structure of
your scene elements. Attributes attached to geometry tells your CG application
what to do with it. Vectors are used in lighting as an essential part of the rendering
algorithm. By comparing light rays to normals, an equation can determine the effect
of light on a face. Transformations allow you to move, reorient, and scale the elements
of your scene to give it life and action. Lights illuminate the elements of your scene
so that a rendered image may be made. Learn how these things interact and what they
can do, and you will understand how CG applications make sense of your instructions.

2.7 Study Questions

• If you didn't use a Cartesian coordinate system, how would you inform your CG

application where your 3D objects were located in space?

• What is the relationship between distance and orientation?