Clouds: noise translates in x and z

Here we apply the same technique to animating clouds. In this case we use the turbulence texture to phase shift the domain of the flow in y (vertically) rather than radially:

  colorMap(y + F(x,y,z))

If you click below to see the animations, you'll see that the animated clouds (as well as the animated flame you saw before) form a cycle. This was done by replacing the perturbation function F(x,y,z) with:

  F2(x,y,z) = (1-z)*F(x,y,z) + z*F(x,y,z-1)

Notice that F2(x,y,0) = F2(x,y,1). Now we can compute the cloud animation from z=0 to z=1:

  colorMap(y + F2(x,y,z))

Click here for a small (113K) cycling animated gif of roiling clouds. Click here for a large (984K) high quality cycling animated gif of the same.