Improvements for Planar reflections.

[anonymous_user_fbe2d247]

@Mariusz.Szaflik

The fix with with adding planar reflection plane as clipping one wont work with 4.20, since in 4.20 there is a check that ViewFrustum.Planes.Num() == 5 in BuildLightViewFrustumConvexHull function - have you by chance managed to modify that function to take into account that Frustum.Planes.Num() == 10 for reflection captures ? (or I must frap my head around that fishy Edges table to fix this) ? (adding those additional clipping planes greatly improves performance, so I do not want to lose this change)

Good catch. You can change the assert to be like this.

check(Frustum.Planes.Num() >= PlaneCount);

But this will not be optimal for planar reflection dynamic shadows. But proper fix to get this optimization for dynamic shadows will be bit more complex and you would need to add more edges to that list. In our project we use static shadows only for planar reflections so I haven’t seen this assert my self.