Graphics Reference
In-Depth Information
Chapter 3
Creating Textures
With a model created, you are ready to make those polygons look like something in the real world. When
light hits a surface, many things can happen. The light can reflect back, pass through, be absorbed into the
surface, or even scattered. The result of this interaction between light and surface defines color, reflectivity,
transparency, and other surface attributes. This chapter serves as an introduction to re-creating those effects
on a 3D model.
This chapter covers the following:
• Understanding surface attributes of real-world objects
• Creating textures in 3D
• Using texture layers
• Using UV mapping
• Creating image-based textures
• Understanding texture channels
Understanding Textures in the Real World
When you look at an object in the real world, what you see is the result of light particles leaving a light source
and bouncing around on everything that they contact. Opaque materials either absorb light or bounce light
back at the viewer. Different materials absorb different wavelengths of light, and the wavelengths that are
bounced back define the color of the surface. If everything is reflected, we see white; if everything is ab-
sorbed, we see black. A similar thing happens with transparent materials. However, much of the light passes
through the surface instead of being absorbed or reflected. Mirrorlike reflection is associated more with the
roughness of a surface. Surfaces that are smooth (on a microscopic level) will result in a visible reflection,
while a rough surface will just show color.
Figure 3-1
shows examples of opaque, transparent, and reflective
(mirror) surfaces.
Figure 3-1:
Photographic examples of opaque (left), transparent (middle), and reflective (right) surfaces
