HLSL Development Cookbook

Hemispheric ambient light

Ambient light is the easiest light model to implement and yet it is very important to the overall look of your scene. For the most part, ambient light refers to any light in the scene that cannot be directly tied to a specific light source. This definition is flexible and its implementation will be shown soon.

In the past, a single constant color value was used for every mesh in the scene that provides a very flat result. As programmable shaders became more available, programmers switched from constant color to other solutions that take the mesh normal into account and avoid the flat look. Hemispheric lighting is a very common method to implement ambient lighting that takes normal values into account and does not require ...