Welded Mesh changed Behaviour with Materials



When welding a mesh I often get a gradient in the material which I do not know how to undo. It has a negative impact on rendering as it creates an unwanted shade. Please have a look at the printscreen below and file attached. Do you know how to solve this issue?
Many thanks

temp.3dm (180.1 KB)

(Pascal Golay) #2

Hi Arthur - that is expected with a welded mesh, depending on the angle. If you want to keep the ‘steps’ in shading you cannot weld to an angle that is great enough to weld across the steps. Why are you welding these at all? Unweld at 0 degrees to restore the steps in shading…

Welding removes the coincident vertices from the adjacent faces - so there is only one vertex and the vertex normal, which is what you see on shading, is averaged from the surrounding faces - thus the faces lose their identity, so to speak, at welded vertices.



Hi Pascal - Thank you so much, it solved the issue. I usually weld at 180 to make sure mesh has no naked edges for fabrication (in this case unfolding with freeform origami). Is that a bad strategy?

(Pascal Golay) #4

Hi Arthur - welding will not remove naked edges, at least I cannot think of how that would be… Post an example if you have one. Welding combines already ‘joined’ vertices, it does not move them closer together .