cloud altitude offset with power fractal

[oysteroid]

I went through the Cloud Function Tutorial by Martin Huisman and have been fiddling with his associated TGD file a bit. When I use a power fractal instead of an image map to displace the landscape and offset the cloud layer, the clouds do have an offset that is similar to the terrain, but not exactly the same. Here it is with an image map:

[attachimg=1]

Here it is with a power fractal instead of an image map:

[attachimg=2]

Everything else is exactly the same.

What's going on here? Am I doing something wrong?

I attached the TGD.

[Matt]

The fractal is 3D, so the Y coordinate is important. When displacing the terrain, the fractal is sampled at the surface of the planet. When rendering the cloud, the fractal is sampled in 3D space for every part of the cloud that's sampled.

Try setting the fractal's noise stretch parameter to (1, 1000000, 1). That stretches the fractal in Y so much that it becomes almost 2D. I think that will probably solve the problem.

Matt

[oysteroid]

Thanks, Matt! That solves the problem.

[bobbystahr]

Awesome, learned something else.....

[Mid-Knight Acchan]

I read "Cloud function tutorial" and read "Cloud Functions Explained.tgd" file in Terragen4.
Then, it did a rendering first.
However, the image which is different from the tutorial was made.
Will something have changed  with 2.2 upgrades?
What value is it  if changing to like an image in the tutorial?

[attachimg=1]