Graphics Programs Reference
In-Depth Information
Figure 19-1: A
normal mapped
plane
The surface in Figure 19-1 is exactly one polygon (or two tri-
angles). This surface is the most simple square surface you
could render in a real-time renderer. In the real-time render-
ing world, the more polygons on an object, the longer it takes
to render that object. As the polycount rises, the frames per
second, or scene renders per second, drop until you are practi-
cally looking at a slide show. However, by using just a simple
256 x 256 pixel texture we can generate a look that seems
nearly identical to the high-poly, sub-d model and avoid this
low frame rate altogether.
A Brief Overview of Creating Normal Maps
Creating a normal map these days is quite simple. Ever since
Max 7, a feature called Render to Texture has given us the
ability to easily generate these textures. Render to Texture is
an amazingly powerful tool that can be used not only for nor-
mal mapping, but also for creating diffuse and global
illumination maps. This tool renders onto the UV coordinates
the detail that shares the surface, hence its name.
To create a normal mapped model you first create a high-
poly model. In this model you can just go absolutely crazy
with the polycount. The number of polygons is only limited by
the RAM installed on the computer you are using.
