While I was developing IITTP (Innovation Inc Thermal Power Power Plant), I found this bug where if I negate an object with another shape with mixed parts, weird flat lines show up in a result.
Even when I redo the union, they still show up. Now my best guess is that Roblox Studio isn’t 3D rendering the union subject correctly, leading to stripped like results.
(Forgive the lighting in the picture, this area isn’t complete yet).
A video can be added if someone wants one 