Manifoldness repair

[pca006132]

Outline

Repair triangle soup that are not manifold.

Details

Basically, a valid solid mesh should be both manifold and has no self-intersection. However, models from the internet may contain defects. This project is about coming up with an algorithm that converts and repair a triangle soup into a manifold mesh.

This will contain a lot of heuristics, basically what we need is:

• Stitching faces together, and maybe join faces that are close enough.
• Fill holes.
• Duplicate vertices and edges such that the result is a manifold in terms of connectivity.

Expected Outcome

Implementation of said algorithm.

Future Possibilities

Project Properties

Skills

• C++
• Graph data structure.
• Algorithms.

Difficulty

Hard.

Size

Long (350h)

Additional Information

• Potential mentor(s): @elalish @pca006132
• Organization website: https://manifoldcad.org/
• Communication channels: https://github.com/elalish/manifold/discussions

[elalish]

We have a starter algorithm for this: Merge() that only merges nearby edges. It's conservative and gives up if the mesh is not close to manifold to begin with. Still, it's a reasonable place to start.

We do not expect a result free of self-intersections for this project - that's a separate project.

In general, a non-manifold mesh can require a lot of heuristic additional surfaces, so part of this project is artistic in nature: what additions make the most sense and look reasonable?