I'm unsure if this is the right place to ask this; I wonder if you could point me to the relevant person(s) about a possible bug in the Wikimedia model viewer. I'd posted the following on the Computing help-desk but didn't get any replies:
I created a few STL files below and found that artifacts appear in the Wikimedia viewer and occasionally the thumbnail. I've checked that the direction of facet vertices is anticlockwise, the normals are sensible and polygons are not duplicated. It seems to happen more where the polyhedron is thin. All these polyhedra render correctly on http://viewstl.com . Would anyone know how to fix these artifacts?
<gallery widths="200" heights="150">