GPU Pro 7

102 II Lighting

Figure 4.8. A slice of the low-frequency noise’s RGBA channels. The first slice is Perin-

Worley noise. The last three are Worley noises at increasing frequencies. (Resolution:

128

3

.)

Figure 4.9. From left to right, a slice of the high-frequency noise’s RGB channels and

Worley noise at increasing frequencies. (Resolution: 32

3

.)

We refer to this as our low frequency Perlin-Worley noise and it is the basis for

our modeling approach. (See Figure 4.7, right.)

Instead of building the FBM using one texture read per octave, we precompile

the FBM so we only have to read two textures. Figure 4.8 shows our first 3D

texture, which is made of the P ...