I am trying to only change the near clipping plane of a given perspective projection matrix for OpenGL. My problem is, that the near clipping plane is way too close, and the far clipping plane is very far away. That causes depth buffer precision problems, which are visible (see image)
Visualization of the artefacts
The wrong parts are marked with red circles.
I would like to solve this issue by only changing the near clipping plane. Is there a fast and easy way to keep all parameter the same except the near clipping plane? I don't have any of the parameters. The only input I have is the ProjectionMatrix which should be changed