Parallax Occlusion Mapping Materials with Pixel Depth Offset Produce Black Artifacts

POM materials with PDO produce flickering black artifacts. This is more noticeable at certain camera angles. 

1. Open Content Examples project, ParallaxOcclusionMapping level
2. Navigate to PDO example, move camera around meshes 

Result: "PDO ON" Example on the left produces black flickering artifacts. The "PDO OFF" example on the right does not.