At the moment you don't. What I'm suggesting is that you could build up a conventional BREP-based datastructure, and than use SDF to "render" it. This gives you

At the moment you don't. What I'm suggesting is that you could build up a conventional BREP-based datastructure, and than use SDF to "render" it. This gives you a very clear separation between your data structure and your meshing algorithm, and as I understand it a big chunk of those "100 man years" would be in dealing with the meshing algorithm and edge cases in it. I suspect that having a generic meshing algorithm that will always mesh your datastructure with no edge cases would significantly reduce the time needed to implement a CAD kernel. You just need an algorithm that can tell you if a given point is inside or outside of your BREP. All you really need for that is a surface that points at a given direction, and the ability to tell whether a point is under the surface or not. Define your surfaces as BREP, render them using SDF, only have to write one meshing algorithm. That being said I disagree with your definition for parametric CAD. Mostly the name, I get that you're talking about BREP based CAD. That is one way to do parametric CAD, but CSG can also work, especially if you can do more advanced operations like a filleted difference or union, or blends between two shapes, or other advanced CSG operations. I don't think that CSG-based CAD is inherently worse as long as you've got the ability to do things like fillet/chamfer CSG operations. You probably don't need to do a fillet along an edge if you can do a fillet where you subtract one object from another, something that SDFs can do easily: https://github.com/fogleman/sdf#smooth_difference https://github.com/fogleman/sdf#smooth_difference