GPU Pro 5

92 II Lighting and Shading

Figure 1.24. Pre-integrated integral of environmental cube-map.

All lights use the same diffuse integral approximation reasoning shown in

Section 1.3.3. Every light, depending on the light shape function, implements

equation (1.16) or equation (1.24) in the case of a textured light source, to ap-

proximate the diffuse integral. That includes sunlight, omnidirectional lights, and

spot lights with sphere, disk, or rectangular light shapes.

Standard analytical dynamic lights, depending on the light shape function,

implement equation (1.20) to approximate the specular integral. In the case of

textured area lights, we support only ...