Z depth / 3D space for points on path.
I do medical illustration for suture techniques. I use a path with a stroke to illustrate the suture (like a string), which need to overlap and show depth. I add a drop shadow to the path, but it simply goes around the entirety of the path's stroke shape, and doesn't apply above segments of the path which should appear below the higher sections.
There needs to be a z-axis system where I can assign a z-depth to each point on a path, which allows the drop shadow effect to apply to the same path on depths below it.
Mark Gould commented
It seems that on some level Z depth, or some approximation of it would be involved in more precision for drop shadow, lighting and other effects, perhaps on new features being explored as well. How will 3D objected in a group translate into After Effects, other 3D programs? How can 3D art in Illustrator be preserved as vector, if the user wishes to preserve it?
Radha, perhaps there is a way to achieve this by other means. Can you share a picture or a draft that illustrates the look you are trying to get?