Another benefit of unwrapping your mesh is render baking. Render baking is the process of creating a flat texture for your mesh that's based on what your mesh looks like when you render it. What good is that? Well, render baking is really useful to people who want to create models for use in video games. Because everything in a game has to run in real time, models can't usually have a lot of complicated lighting or highly detailed meshes with millions of vertices. To get around this limitation, you can fake some of these effects by using a texture. And rather than paint on shadows and detail by hand, you can let the computer do the work and use a high-resolution render instead.
Although this technique is used a lot in video games, render baking is also helpful when creating animated models for film or television. If you can create a model that looks really detailed but still has a relatively low vertex count, your rendering and animating process goes faster.
Another use of render baking is for texture painters. Sometimes it's helpful to have an ambient occlusion or shadow texture as a frame of reference to start painting a more detailed texture. A technique that I like to use is to first rough in colors with vertex painting (see Chapter 7). Then you can bake out those vertex colors to a texture, which can serve as a great starting point for a hand-painted texture.
So how do you create these baked textures? Well, the magic all happens in the Bake ...