Rendering and User Input - Learning Game Physics with Bullet Physics and OpenGL - page 33

the rendering steps through the use of custom scripts called shaders . Shaders can
vary from very simple scripts that render objects with ambient shading, to complex
procedures that render effects such as motion blur, HDR lighting, produce millions
of pixel-sized particles, depth of field, and many more. There are even several lan-
guages that can be used to write shaders (common ones are Cg, GLSL, and HLSL),
and they can be used to produce any graphical effect you want to render (depending
on performance limitations, of course). Entire volumes can, and have been written
on the nuances of writing shaders with all the various languages, algorithms, and
styles of programming they support, making their understanding a highly skilled and
highly valued area of 3D graphics programming.
But, don't feel that you've wasted time learning the fixed-function pipeline, because
the programmable pipeline can be utterly bewildering if you haven't established a
firm grasp of the fundamentals through the fixed-function pipeline first.