Conditioned out a few instructions (possibly) in the zin == 0 section of the PerspectiveRenderingMode == 1 clause.
Conditioned out a few instructions (possibly) in the zin == 0 section
of the PerspectiveRenderingMode == 1 clause.

zhangfangyan/devide.vtkdevide,zhangfangyan/devide.vtkdevide,zhangfangyan/devide.vtkdevide