Potential values give a different shape to the 3D image than distance estimates. I really need to add continuous potential values as an option. Then I could probably recreate the look of this cover image much more accurately.

However, the data structures start to get quite large. I already offer distance estimates and fractional iteration values for every pixel. Both are arrays of floats, at 32 bits/pixel. Adding continuous potential would increase my memory use by another 32 bits/pixel. (16 bits/pixel for iteration value, 32 bits for DE values, 32 bits for fractional iteration value, plus 32 bits/pixel for potential value, not to mention display color values, 3D vertex and normal data, etc, etc.

I might fudge my fractional iteration values to be only the fractional part, since I store the integer iteration value separately. I could probably get away with a single byte, since fractional iteration values are really only used for smooth color transitions. I suspect 256 shades of color between iteration values would be plenty for smooth shading.


Duncan C