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BrunoLevy / geogram

a programming library with geometric algorithms
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Question about Co3Ne and mesh repair #53

Closed starseeker closed 1 year ago

starseeker commented 1 year ago

I doubt that this is an issue - more of a question/confirmation request about what the expected capabilities and limitations are of the geogram algorithms.

One of our CAD system's fallback facetization routines for implicit boolean geometry is to shoot rays, generate a point cloud, and then do surface reconstruction. Usually we use PoissonRecon, but that fails fairly miserably for super thin, large surface area solids. I tried such an example with geogram's Co3Ne and got very interesting results (see images below). However, the mesh doesn't appear to be (quite) fully manifold and surface repair seems to be unable to completely resolve the issues. Is this normal/expected for this type of input data set?

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BrunoLevy commented 1 year ago

Difficult for me to see, is it a surface, or is it a very thin volume with a closed boundary ? If it is a very thin volume with a closed boundary, for Poisson reconstruction, make sure you generate normals with the points. Make sure also that you use a sufficiently large depth to capture the thickness of the surface.

starseeker commented 1 year ago

The original source of the point cloud is two very thin volumes with closed boundary defined by implicit primitive booleans. I need to dig more deeply into the algorithms to ask more intelligent questions, so I'll go ahead and close this out - thanks!