With the initial rollout of v. 16.2 with compound rotations, I’m starting to work on shading, which should be especially helpful for gradients in extruded shapes.

First, I don’t see a reason why we can’t have a user-definable light source. Sorry, only one, though, at least to start.

There’s a mathematical formula for shading, based on the angle the light hits the surface, that actually pinches the midtones and shadows fairly close together. I think that leaves most surfaces too light, with too little differentiation in value, especially if we want to try to show the original color on one of the axonometric planes. There must be some compromise between clarity and realism. With gradients, especially, it’s probably important to add ambient light reflected back on the back side. I’m hoping, too, to allow a gloss value to put a highlight on the gradient. It would be nice to add a little highlight on all rounded edges, but that’s probably more than this non-3D system is capable of!

With the tools built into the developer libraries, colors can easily be treated as, or converted between RGB, CMYK, HSB, LAB, and grayscale. That should give some good options for shading.

If you have any thoughts on color adjustments in shading, please feel free to share!