[vtkusers] Need for spherical to cartesian nonlinear transformation.

[Roland Schwarz]

I am about to write a spherical to cartesian transformation class.

Before I start work I'd like to ask if anyone already has done this?
In this case I kindly would ask if he/she would share the code?

BTW.: I am considering to directly derive from vtkAbstractTransform. There
is another class called vtkWarpTransform. Is this a better candidate for my
task? As far as I can see the difference is that the latter can do inverse
by newtons method, which I do not consider meaningful in my case since my
transform as well as its inverse are defined analytically.

Thank you,
Roland