Rectangle has good support for participating in occlusion culling for opaque paints by virtue of its implementation of computeOpaqueRegion. Region has some support for it, but fails for several use cases among which are opaque paints. Circle and Ellipse have no support but would be as cheap to support as Rectangles, so they should support being an occlusion root as well.

NGImageView could also be an occlusion root fairly easily since prism Images can tell us what their pixel format is, making it relatively straightforward to determine cheaply whether the image is an occlusion culling capable dirty root.