This function generates a fractal pattern which looks like rust.
The return values run between [-1,1]. In order, the get values
between [0,1], try using modulus, abs, shift or contrast on the output.

This must be a varying point.  The default is the surface point, P.

This must be a float.  The default is 0.8.
This value controls the frequency of the pattern.

This must be a float.  The default is 8.0.
This value controls the amount of turbulence in the pattern.

This function returns a fractal pattern which looks like rust.
The return values run between [-1,1]. In order, the get values
between [0,1], try using modulus, abs, shift or contrast on the output.