Can you give me an example of how this would look like? This is an ongoing series so at the moment my solver can't solve much :D
https://cad.onshape.com/help/Content/constraints.htm
Onshape is free to demo, so give it a whirl?
Basically you write a renderer for some data and have a constraint solver (just backprop I think for g9) to solve for the best data that will render something that fits the user input.