I hope this is the good place to post such a question; if not, sorry about that.
Here it is: L2AV and L2AV.003 are the two sides of a boat’s bridge girder. As far as I can see, they are correctly oriented : L2AV’s face normals point out of the geometry, L2AV.003’s point inside. None of the two meshes is flagged as “Double Sided”.
Yet when they are rendered, hideous artefacts appear.
Thanks for your help,
Test.zip (78.9 KB)