1rtcSetGeometryOccludedFuncEtmiborne(e3)Ray Tracing KerrtnceSlestG3eometryOccludedFunction(3)
2
3
4
5   NAME
6              rtcSetGeometryOccludedFunction - sets the callback function to
7                test a user geometry for occlusion
8
9   SYNOPSIS
10              #include <embree3/rtcore.h>
11
12              struct RTCOccludedFunctionNArguments
13              {
14                int* valid;
15                void* geometryUserPtr;
16                unsigned int primID;
17                struct RTCIntersectContext* context;
18                struct RTCRayN* ray;
19                unsigned int N;
20                unsigned int geomID;
21              };
22
23              typedef void (*RTCOccludedFunctionN)(
24                const struct RTCOccludedFunctionNArguments* args
25              );
26
27              void rtcSetGeometryOccludedFunction(
28                RTCGeometry geometry,
29                RTCOccludedFunctionN filter
30              );
31
32   DESCRIPTION
33       The  rtcSetGeometryOccludedFunction  function registers a ray/primitive
34       occlusion callback function (filter argument) for  the  specified  user
35       geometry (geometry argument).
36
37       Only  a  single  callback  function can be registered per geometry, and
38       further invocations overwrite the  previously  set  callback  function.
39       Passing NULL as function pointer disables the registered callback func‐
40       tion.
41
42       The registered callback function is  invoked  by  rtcOccluded-type  ray
43       queries  to  test whether the rays of a packet of variable size are oc‐
44       cluded by a user-defined primitive.  The callback function of type  RT‐
45       COccludedFunctionN gets passed a number of arguments through the RTCOc‐
46       cludedFunctionNArguments structure.  The  value  N  specifies  the  ray
47       packet size, valid points to an array of integers which specify whether
48       the corresponding ray is valid (-1) or invalid (0), the geometryUserPtr
49       member  points to the geometry user data previously set through rtcSet‐
50       GeometryUserData, the context member points to the intersection context
51       passed to the ray query, the ray member points to a ray packet of vari‐
52       able size N, and the geomID and primID member identifies  the  geometry
53       ID and primitive ID of the primitive to intersect.
54
55       The  task of the callback function is to intersect each active ray from
56       the ray packet with the specified user primitive.  If the  user-defined
57       primitive is missed by a ray of the ray packet, the function should re‐
58       turn without modifying the ray.  If an intersection of the user-defined
59       primitive  with  the  ray  was  found in the valid range (from tnear to
60       tfar), it should set the tfar member of the ray to -inf.
61
62       As a primitive might have multiple intersections with a ray, the occlu‐
63       sion filter function needs to be invoked by the user geometry occlusion
64       callback for each encountered intersection, if filtering  of  intersec‐
65       tions  is desired.  This can be achieved through the rtcFilterOcclusion
66       call.
67
68       Within the user geometry occlusion function, it is safe  to  trace  new
69       rays and create new scenes and geometries.
70
71   EXIT STATUS
72       On  failure  an  error  code is set that can be queried using rtcGetDe‐
73       viceError.
74
75   SEE ALSO
76       [rtcSetGeometryIntersectFunction], [rtcSetGeometryUserData], [rtcFilte‐
77       rOcclusion]
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79
80
81                                             rtcSetGeometryOccludedFunction(3)