Blender Git Loki

Fix T69911: Adaptive subdivision offscreen dicing does not work correctly if the camera is shifted

Code was assuming frustrum planes are symmetrical which is not the case
for shifting. This lead to a shrinking region if shift was negative (and
a growing region if shift was positive)

So instead of only keeping track of plane on one side (and mirroring
over in code) get the actual planes after shifting and use these
instead.

This code corrects this for ortho and perspective cameras, it does not
touch panoramic cameras.

Reviewed By: brecht

Maniphest Tasks: T69911

Differential Revision: https://developer.blender.org/D9342