Clouds have distinctive shape, that is due to the fractal nature of cloud. Fractals are geometrical entities that have no intrinsic length scale. They are self-similar, that is they repeat themselves at any scale you pick. I am going to use the fractal tool in Houdini for the creation of volumetric cloud and terrain.
Technical Aspect:
1.The first technical challenge is to change a uniform volume into a cloud which has a density drop down from center to the edge. To solve this problem, I mapped a 2D image which is red in the middle and gradually change to black radically.
2.Make cloud look
Cloud has distinctive shape which is actually fractal. But at first I want to try other method rather than fractal to mimic cloud. I used turbulent noise to change volume density field. The following picture is network graph:
The following is the test sample that I got from the method I mentioned above:
Aesthetic Aspect:
The following is a playblast from a flying over camera angle. I didn't render them out because it kinda of too time consuming:
