Specifies the order for positions or front facing triangles. Winding order is important for triangulation and backface culling.

Member	Value	Description
eStkGraphicsWindingOrderCounterClockwise	0	Positions or triangles are defined in counter-clockwise order.
eStkGraphicsWindingOrderClockwise	1	Positions or triangles are defined in clockwise order.
eStkGraphicsWindingOrderCompute	2	The winding order is unknown and should be computed. For best performance, only use this value if you do not know the actual winding order.

Triangle Mesh Overview - Triangulators  | Backface Culling Performance Overview