GPU Pro 6

156 II Rendering

Particle generation. The next stage consists of processing valid and visible voxels

of the cloud lattice and generating particles for some of them. To generate the

required number of threads, we again use the simple one-thread compute shader.

The particle generation shader loads the cloud density from the density lattice

and, if it is not zero, it creates a particle. The shader randomly displaces the

particle from the voxel center and adds a random rotation and scale to eliminate

repeating patterns. The shader writes the particle attributes, such as position,

density, and size, into the particle info buffer and adds the particle index ...