1RTC_GEOMETRY_TYPE_USER(3)Embree Ray Tracing Kernels 3RTC_GEOMETRY_TYPE_USER(3)
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5   NAME
6              RTC_GEOMETRY_TYPE_USER - user geometry type
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8   SYNOPSIS
9              #include <embree3/rtcore.h>
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11              RTCGeometry geometry =
12                rtcNewGeometry(device, RTC_GEOMETRY_TYPE_USER);
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14   DESCRIPTION
15       User-defined  geometries  contain  a number of user-defined primitives,
16       just like triangle meshes contain multiple triangles.  The shape of the
17       user-defined  primitives is specified through registered callback func‐
18       tions, which enable extending Embree with  arbitrary  types  of  primi‐
19       tives.
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21       User-defined  geometries  are created by passing RTC_GEOMETRY_TYPE_USER
22       to the rtcNewGeometry function call.  One has  to  set  the  number  of
23       primitives  (see rtcSetGeometryUserPrimitiveCount), a user data pointer
24       (see rtcSetGeometryUserData), a bounding function closure (see  rtcSet‐
25       GeometryBoundsFunction), as well as user-defined intersect (see rtcSet‐
26       GeometryIntersectFunction) and  occluded  (see  rtcSetGeometryOccluded‐
27       Function)  callback  functions.  The bounding function is used to query
28       the bounds of all time steps of a user primitive, while  the  intersect
29       and  occluded  callback functions are called to intersect the primitive
30       with a ray.  The user data pointer is passed to each  callback  invoca‐
31       tion  and  can  be used to point to the application's representation of
32       the user geometry.
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34       The creation of a user geometry typically looks the following:
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36              RTCGeometry geometry = rtcNewGeometry(device, RTC_GEOMETRY_TYPE_USER);
37              rtcSetGeometryUserPrimitiveCount(geometry, numPrimitives);
38              rtcSetGeometryUserData(geometry, userGeometryRepresentation);
39              rtcSetGeometryBoundsFunction(geometry, boundsFunction);
40              rtcSetGeometryIntersectFunction(geometry, intersectFunction);
41              rtcSetGeometryOccludedFunction(geometry, occludedFunction);
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43       Please have a look at the rtcSetGeometryBoundsFunction, rtcSetGeometry‐
44       IntersectFunction,  and rtcSetGeometryOccludedFunction functions on the
45       implementation of the callback functions.
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47       Primitives of a user geometry are ignored during rendering  when  their
48       bounds  are  empty, thus bounds have lower>upper in at least one dimen‐
49       sion.
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51       See tutorial [User Geometry] for an example of how to use the  user-de‐
52       fined geometries.
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54   EXIT STATUS
55       On  failure  NULL  is  returned  and  an  error code is set that can be
56       queried using rtcGetDeviceError.
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58   SEE ALSO
59       [rtcNewGeometry],   [rtcSetGeometryUserPrimitiveCount],   [rtcSetGeome‐
60       tryUserData], [rtcSetGeometryBoundsFunction], [rtcSetGeometryIntersect‐
61       Function], [rtcSetGeometryOccludedFunction]
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65                                                     RTC_GEOMETRY_TYPE_USER(3)
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