HTML and CSS Reference
In-Depth Information
Chapter 17
Backface Culling and 3D Lighting
What we'll cover in this chapter:
Backface culling
Enhanced depth sorting
3D lighting
In the previous chapter, we looked at the basics of modeling 3D solids: how to create the points, lines, and
polygons that make up a form, and how to give each polygon a color. But if you recall, that color was left at
50% transparency, so you could see right through it. Although we created some complex 3D shapes, the
models still lack a lot in terms of realism.
In this chapter, we fix that by learning about backface culling (not drawing the polygons facing away from
you), enhanced depth sorting (we covered this a bit in Chapter 15, but we take a new look at it in terms of
polygons), and 3D lighting.
You should be amazed at the results on your 3D models once these three techniques are applied. After
the first two, you will be able to create 3D solids that look solid. And with 3D lighting, they really come
alive.
In the examples presented here, we build on the rotating, extruded, 3D letter A that was created in the
previous chapter. This serves as a sufficiently complex model that makes it obvious if you do something
wrong, and looks pretty good when you do everything right! The foundation of this chapter was provided by
the techniques described by Todd Yard in Chapter 10 of
Macromedia Flash MX Studio
(friends of ED,
2002).
