x coordinate in noise space
y coordinate in noise space
z coordinate in noise space
power-of-two tiling period along x (0 = no wrapping)
power-of-two tiling period along y (0 = no wrapping)
power-of-two tiling period along z (0 = no wrapping)
noise value, roughly in [-1, 1]
Samples 3D classic Perlin gradient noise (stb_perlin port).