RTC_GEOMETRY_TYPE_USER - user geometry type
#include <embree3/rtcore.h> RTCGeometry geometry = rtcNewGeometry(device, RTC_GEOMETRY_TYPE_USER);
User-defined geometries contain a number of user-defined primitives, just like triangle meshes contain multiple triangles. The shape of the user-defined primitives is specified through registered callback functions, which enable extending Embree with arbitrary types of primitives.
User-defined geometries are created by passing
RTC_GEOMETRY_TYPE_USER to the
rtcNewGeometry function call. One has to set the number of primitives (see
rtcSetGeometryUserPrimitiveCount), a user data pointer (see
rtcSetGeometryUserData), a bounding function closure (see
rtcSetGeometryBoundsFunction), as well as user-defined intersect (see
rtcSetGeometryIntersectFunction) and occluded (see
rtcSetGeometryOccludedFunction) callback functions. The bounding function is used to query the bounds of all time steps of a user primitive, while the intersect and occluded callback functions are called to intersect the primitive with a ray. The user data pointer is passed to each callback invocation and can be used to point to the application's representation of the user geometry.
The creation of a user geometry typically looks the following:
RTCGeometry geometry = rtcNewGeometry(device, RTC_GEOMETRY_TYPE_USER); rtcSetGeometryUserPrimitiveCount(geometry, numPrimitives); rtcSetGeometryUserData(geometry, userGeometryRepresentation); rtcSetGeometryBoundsFunction(geometry, boundsFunction); rtcSetGeometryIntersectFunction(geometry, intersectFunction); rtcSetGeometryOccludedFunction(geometry, occludedFunction);
Please have a look at the
rtcSetGeometryOccludedFunction functions on the implementation of the callback functions.
Primitives of a user geometry are ignored during rendering when their bounds are empty, thus bounds have lower>upper in at least one dimension.
See tutorial [User Geometry] for an example of how to use the user-defined geometries.
NULL is returned and an error code is set that can be queried using
[rtcNewGeometry], [rtcSetGeometryUserPrimitiveCount], [rtcSetGeometryUserData], [rtcSetGeometryBoundsFunction], [rtcSetGeometryIntersectFunction], [rtcSetGeometryOccludedFunction]