simple 2d clouds

I have to create simple 2d clouds textures i开发者_StackOverflown java so that they can be used in kml files and visualized in Google Earth. The thing is that I have some real data that depict cloud fraction over my country - points of latidude and longitude and value related to each point that describes the level of cloudiness from 0 (no clouds) to 100. So I cannot just randomly render some clouds but the visualization must reflect the real measurements. What is the best way to do that? I used VTK for weather visualization but I don't know how to create clouds using this library and my data.

You could use Perlin Noise style clouds, but weight the lowest frequency noise in the algorithm with the "cloudiness" factor.

I.e. if you used 3D Perlin Noise, you'd probably want to have some cutoff value to determine whether it is a cloud or empty air (P(x, y, z) > a). Then if you weighted the lowest frequency noise for both position in space and for the cloudiness, in effect you're raising or lowering the probability for clouds to exist at that point while still allowing for some degree of randomness.