GPU Pro 6

56 I Geometry Manipulation

Figure 4.3. A collection of explosions rendered using different primitive types.

The color of the explosion at each step is calculated by performing a lookup

into a gradient texture using the

displacementOut parameter (from Listing 4.1) as

a texture coordinate. This color is then blended with the other samples gathered

from previous steps before the next step of the ray.

This process is repeated either until we hit the exit point of our ray or, as

a further optimization, until the output color has reached full opacity and no

further steps would contribute to the final color of the pixel. (It is important to

note that this optimization ...