Adaptive Subdivision Occlusion Dicing Scale for polygons that are occluded.

Currently there is only "Offscreen Dicing Scale", which adjusts the Dicing Rate if the polygons are outside of the camera frustum. It would be great to have a similar option for polygons that are occluded. For example the back face of a mountain or parts of a landscape behind a large occluder.

This option could be added underneath "Offscreen Scale" and be called "Occlusion Scale"