points by tixylix 1 day ago | 0 comments
> the SMLib kernel they are currently porting to Rust from Nvidia is currently about a decade behind OpenCascade, nevermind Parasolid/ACIS as they are still converting all geometry to NURBS instead of preserving analytical geometry , which means that their initial development is easier but it creates a near infinite amount of edge cases once they start going heavy into booleans and fillet/chamfers.
Where are you getting this information from? Booleans and fillets at least use analytic geometry:
Analytic fillets:
https://gitlab-master.nvidia.com/omniverse/solidmodeling/-/b...
Analytic surface intersection (example of sphere/cone) used by booleans:
https://gitlab-master.nvidia.com/omniverse/solidmodeling/-/b...
[–] YuechenLi 1 day ago
Ok, I think I oversimplified it too much previously, the more accurate way to word the difference is that in OCCT/ACIS/Parasolid, NURBS and analytical surfaces are separate entities altogether, whereas SMLib, due to its heritage, uses NURBS as the underlying representation of everything and only use analytical surfaces as shortcuts, and even their analytical surfaces are built on top of NURBS.
Fillets: https://github.com/NVIDIA-Omniverse/usd-brep/blob/main/sourc...
Intersections: https://github.com/NVIDIA-Omniverse/usd-brep/blob/main/sourc...