I have to join two almost identical meshes together. Both objects are with same size, same scale, same origin, same x,y,z origin coordinates (snapped to grid). Why is it that after joining these two meshes together as one object (ctrl+j) suddenly faces start to flicker - which means there are some imprecision between vertices of 1st and 2nd object, while they are identical and positioned identically.
The only partial cure i have found is select all vertices and snap to grid . Flickering ends but that ruins some sphere parts of my mesh.
It would help if you provided several screenshots of your mesh, what are you doing and what are you trying to achieve.
Generally “flickering” that you see could be caused by z-fighting. This happens when several faces are in the same place and there’s no possibility for program to decide which one should be higher.
It’s not clear why you want to join 2 identical meshes though because this will drastically increasy complexity of the final model.
Face flickers in blender only if vertices are little bit off, like a tiny tiny value. If they are perfectly identical - no flickering in blender viewport happens. Why I need this is another story, and getting into the details will not solve the core problem. So I would pretty much appreciate if we could concentrate on the precision issue here. Thanks
Faces will indeed flicker with a perfect overlap. In my experience, a small offset actually helps to solve the problem.
Looks like it happens more frequently when the verts/faces are joined into a single object. In this example, everything is identical in both groups, except in the lower one they have been joined together to the same object:
Hey there, thank you for your examples. In your Joined object, if you make blue and green squares identical size and overlap them + do snap to grid for vertices - no flickering is being observed.
