Check surface objects visibility based on terrain tiles sectors intersection instead of frustum culling

[ComBatVision]

Each image layer and surface shape or image calculates its own bounding box, access elevation model and makes frustum intersection instead of just checking if it intersect current terrain in 2d, which already intersected frustum in this frame during tessellation.

Surface objects cannot be outside terrain, so it will be good to find approach how to effectively check terrain sectors intersection instead of frustum culling.

Be aware, that intersection with whole terrain sector union is bad approach as it will render a lot of tiles to the left and right side from camera because terrain sector union width will be based on the most distant terrain tile sectors width.