rtcGetGeometryOppositeHalfEdge - returns the opposite half edge
#include <embree3/rtcore.h> unsigned int rtcGetGeometryOppositeHalfEdge( RTCGeometry geometry, unsigned int topologyID, unsigned int edgeID );
The rtcGetGeometryOppositeHalfEdge function returns the ID of the opposite half edge of the specified half edge (edgeID argument) in the specified topology (topologyID argument). For instance in the following example the opposite half edge of e6 is e16.
An opposite half edge does not exist if the specified half edge has either no neighboring face, or more than 2 neighboring faces. In these cases the function just returns the same edge edgeID again.
This function can only be used for subdivision geometries. The function depends on the topology as the topologies of a subdivision geometry have different index buffers assigned.
On failure an error code is set that can be queried using rtcGetDeviceError.
[rtcGetGeometryFirstHalfEdge], [rtcGetGeometryFace], [rtcGetGeometryOppositeHalfEdge], [rtcGetGeometryNextHalfEdge], [rtcGetGeometryPreviousHalfEdge]