Recently I had to cut one object into two, and I did it like this - I've selected mesh that I wanted to separate in Edit Mode, duplicated the object in Object Mode, then deleted my selection in Edit Mode in one object, and inversion of it in second object.
And because of this I am facing an issue right now, that you can see in screens below. Basically shading of some flat surfaces is wierd, depending on camera position in scene.
What doen't fix the issue (I tried)
- Regenerating UVs (every projection)
- Recalculating normals
- Not using normalmap or changing any material setting (it just made it less visible)
- Sun rotation or strength
- Rotation or position of object itself
- HDRi scene background
- Shade flat/smooth