The cubemap face of Sector.
Bitmask of mesh sector quadrants. Bits 0 to 3 represent the mesh quadrants.
A value of
0xF means that all four mesh sector quadrants shall be rendered (i.e. the entire Sector).
The mesh sector.
By convention, an explicit sector mark (see MeshTree.SectorMark) is put onto a sector when a batch is generated for it.