3D cartesian to polar conversion in jitter

Dear all. I want to perform cartesian -> polar coordinate conversion in 3D (XYZ -> AED) using jitter but can't find an obvious way to do this. Does anyone have experience of doing this please?

Failing that someone may be able to correct my method of achieving something; I want to create a 3D grid that I can shrink and expand to go from a single start point to surrounding an object. The way I tried was to plot a vector from the start point to the final resting position and scale this vector in order to control the growth of the grid. However, what this is doing is controlling the volume of the dome, and not causing it to expand along a spherical surface (almost like dragging the grid out along an arc-shaped virtual curtain rail). My solution was to work in AED differences and scale those instead but I'm sure there will be a more mathematically efficient way of doing it...

Any help is much appreciated. C