SSRPass: Correct Reflector depth 2.

[gonnavis]

Turned out that this problem is caused by inconsistent virtualCamera.projectionMatrix and virtualCamera.projectionMatrixInverse.

Because of projectionMatrix is copied from camera, so need use camera's projectionMatrixInverse too. No need worldYBias now.

This also solved slight worldY change problem when rotating, and solved the newly found more severe change problem when pan, all caused by the same reason.

before vs after ( try pan the scene )

[mrdoob]

Sweet!

[mrdoob]

Thanks!