The order in which markers in a marker batch are sorted before rendering.

Member	Value	Description
eStkGraphicsMarkerBatchSortOrderBackToFront	0	The markers are sorted in back to front order before rendering. For overlapping translucent markers, this enables correct blending results. This may not perform as well as ByTexture since the CPU has to sort the markers when the camera moves or a marker changes position.
eStkGraphicsMarkerBatchSortOrderFrontToBack	1	The markers are sorted in front to back order before rendering. For overlapping opaque markers, this can enable the GPU to quickly eliminate markers that are hidden behind other markers. In many cases, this may not perform as well as ByTexture since the CPU has to sort the markers when the camera moves or a marker changes position.
eStkGraphicsMarkerBatchSortOrderByTexture	2	The markers are sorted by texture. This minimizes costly texture changes during rendering and does not require resorting when the camera moves or a marker changes position.

Marker Batch Primitive Overview  | IAgStkGraphicsMarkerBatchPrimitive