You would probably find "A Unified Differentiable Boolean Operator with Fuzzy Logic" interesting! https://arxiv.org/abs/2407.10954 https://arxiv.org/abs/2407.1

You would probably find "A Unified Differentiable Boolean Operator with Fuzzy Logic" interesting! https://arxiv.org/abs/2407.10954 https://arxiv.org/abs/2407.10954 They build up CSG trees with differentiable leafs (quadrics) combined with differentiable boolean-ish operations, so you can hill-climb over the entire shape.