Function portalExitClipPlane

portalExitClipPlane(
    exitWorld: Matrix4,
    cameraWorld: Matrix4,
    out?: Plane,
    bias?: number,
): Plane
Advanced
Writes the exit surface as a clipping plane in the portal camera's view space

Set the result as the camera's Camera3D#clippingPlane and it keeps only what lies beyond the exit, so the wall the exit sits in, and anything else between the camera and the opening, is left out. The plane sits bias past the surface, so the exit quad itself is cut too rather than flickering across the opening.
Parameters
- exitWorld: Matrix4
  World transform of the exit portal; its +Z side is kept.
- cameraWorld: Matrix4
  World transform of the portal camera, as mirrorCameraThroughPortal wrote it; the camera's view matrix still holds last frame's pose at that point.
- out: Plane = ...
  Plane to write into.
- bias: number = 0.001
  How far past the exit surface to cut, in world units. The default suits a scene authored in metres; scale it with the scene.
Returns Plane
The written plane, in the camera's view space.