SurfaceTransparentCompare using bounding box

[ivan.cuevas]

Problem

In our scenes, we use many objects with transparent textures. The problem is Unigine uses the bounding sphere for depth sorting, and when some planes, with different sizes, are placed very close each other (in a symbol composition this is a very common situation) it produces visual artifacts. We tried to avoid this conflict making planes of the same size, but in some cases this doesn't solve the problem and, in some symbol compositions, it's very difficult to put it in practice.

 

Suggestion

In other engines this problem does not exist because they uses the boundingbox for transparent object sorting. I think Unigine can support this functionality easily just modifying the SurfaceTransparentCompare class adding an extra parameter in constructor and implementing functionality (of course :) ):

 

enum { USE_BOUNDSPHERE_MODE, USE_BOUNDBOX_MODE };
SurfaceTransparentCompare(Vector<ObjectSurface*> &surfaces,const vec3 &camera,SortingMode mode=USE_BOUNDSPHERE_MODE)

 

Thanks,

Iván.

[frustum]

Transparent surfaces will be sorted by distance to theirs OBB in next update.

I don't expect great sorting improvement in compare to current implementation.