GPU Pro 5

4. Hi-Z Screen-Space Cone-Traced Reflections 179

Figure 4.23. Cone-tracing algorithm capable of producing glossy reflections in screen

space. Notice how the algorithm ensures that the further the reflection is from caster,

the more spread it becomes like in the real world.

There is a conflict between the Hi-Z tracer and the cone tracer. Hi-Z tries to

find a perfect specular as fast as possible while the cone tracer needs to take linear

steps to integrate the total visibility in front-to-back order for correct occlusion.

This is not shown in this chapter because of complexity but the Hi-Z buffer

is actually used together with the cone angle to find an ear