rtcGetGeometryPreviousHalfEdge - returns the previous half edge
#include <embree3/rtcore.h> unsigned int rtcGetGeometryPreviousHalfEdge( RTCGeometry geometry, unsigned int edgeID );
The rtcGetGeometryPreviousHalfEdge function returns the ID of the previous half edge of the specified half edge (edgeID argument). For instance in the following example the previous half edge of e6 is e5.
This function can only be used for subdivision geometries. As all topologies of a subdivision geometry share the same face buffer the function does not depend on the topology ID.
On failure an error code is set that can be queried using rtcGetDeviceError.
[rtcGetGeometryFirstHalfEdge], [rtcGetGeometryFace], [rtcGetGeometryOppositeHalfEdge], [rtcGetGeometryNextHalfEdge], [rtcGetGeometryPreviousHalfEdge]