[Paraview] Suggestion for STL import

[Eugene de Villiers]

Hi,

When importing STL format geometry or similar, where connectivity information is not implicit in the data structure, it appears that the connectivity is reconstructed via an  octree search. This is very inefficient when surfaces with large differences in edge length are imported – we have had a recent case where an STL took 45mins to load. If the same input geometry is converted to OBJ format via an external tool, the load time reduces to minutes.

A generally more efficient method is to calculate the distance of each point from a location outside the point cloud bounding box and then to bubble-sort the resulting list. Unless you are dealing with a pathological case your local search neighbourhood of identical distance points will be small and the algorithm very fast. More complex, multi-origin algorithms are also possible to counter pathological instances.

I can provide more details and sample code if you are interested.

Best regards,

Eugene de Villiers
Managing Director
e.devilliers at engys.com<mailto:e.devilliers at engys.com>
Mob: +44 (0) 77 89748490
Tel: +44 (0)20 32393041 (ext. 102)
Fax: +44 (0)20 33573123
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