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slic3r / Slic3r

Open Source toolpath generator for 3D printers
https://slic3r.org/
GNU Affero General Public License v3.0
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Auto-repair the normals of nested shells #1502

Open alranel opened 11 years ago

alranel commented 11 years ago

When a solid has a cavity, and thus has two nested shells, OpenSCAD exports the inner one with reversed normals. The usual trick is to make a tiny hole connecting the two shells to make a single one.

Ideally, Slic3r should be able to detect this situation and reverse the normals of the inner shell.

This was discussed, with a test model, in #1472

microGen commented 10 years ago

Blender also messes up the normals of internal cavities / nested shells (created by boolean subtractions). Furthermore, the STL export is severely lacking in features, assigning (0, 0, 0) to every normal. Thus, Slic3r cannot handle the blender-exported STL files correctly, even if the STL export was fixed. I have tested and verified this problem with two files which I can provide if needed. I also understand that this is more a problem of the 3D editor software, but an auto-repair function in Slic3r for these issues would be nice.