[OpenSCAD] Visually and by inspecting code: surface looks perfect - But: "Object may not be a valid 2-manifold and may need repair"
ed.nisley at pobox.com
Mon May 18 16:30:52 EDT 2015
On 05/18/2015 02:51 PM, kaefert at gmail.com wrote:
> something wrong in my code
It's not exactly *wrong*, but the order in which you specify the points
of a polygon / polyhedron determine which way the surface normals point:
"When looking at the face from the outside inwards, the points must be
clockwise. You can rearrange the order of the points or the order they
are referenced in each tuple. [...] Note that if your polygons are not
all oriented the same way OpenSCAD will either print an error or crash
Given the way that you're generating the points, at least some of the
polyhedrons may be wound backwards.
The reason this doesn't show up in thrown-together mode may be due to
the way the polyhedrons combine: everything looks fine from the outside,
but some inside (invisible) faces wind backwards. Perhaps assembling one
polyhedron at a time will be productive.
Using Meshlab (or something similar) to check your work may also help
pin this down.
It's a nice-looking prop, though!
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