Reverse-z depth buffer
After multiple discussions a conclusion was that a proper solution for depth precision issues in OpenMW is to setup a reverse-z float depth buffer (with framebuffer, which also can be used for post-processing).
As a temporary workaround we increased a near clip value to mitigate z-fighting, we will need to set it again to 1 once this feature will be implemented.
Edited by Andrei Kortunov