1rtcIntersect1(3)         Embree Ray Tracing Kernels 3         rtcIntersect1(3)
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3
4
5   NAME
6              rtcIntersect1 - finds the closest hit for a single ray
7
8   SYNOPSIS
9              #include <embree3/rtcore.h>
10
11              void rtcIntersect1(
12                RTCScene scene,
13                struct RTCIntersectContext* context,
14                struct RTCRayHit* rayhit
15              );
16
17   DESCRIPTION
18       The  rtcIntersect1  function finds the closest hit of a single ray with
19       the scene (scene argument).  The  provided  ray/hit  structure  (rayhit
20       argument) contains the ray to intersect and some hit output fields that
21       are filled when a hit is found.
22
23       The user has to initialize the ray origin (org ray member), ray  direc‐
24       tion  (dir  ray member), ray segment (tnear, tfar ray members), and set
25       the ray flags to 0 (flags ray member).  If the  scene  contains  motion
26       blur  geometries,  also the ray time (time ray member) must be initial‐
27       ized to a value in the range [0, 1].  If ray masks are enabled at  com‐
28       pile  time, the ray mask (mask ray member) must be initialized as well.
29       The ray segment has to be in the range [0, ∞], thus ranges  that  start
30       behind  the ray origin are not valid, but ranges can reach to infinity.
31       See Section [RTCRay] for the ray layout description.
32
33       The instance ID (instID hit member) and geometry ID (geomID hit member)
34       of the hit data must be initialized to RTC_INVALID_GEOMETRY_ID (-1).
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36       Further,  an  intersection  context  for the ray query function must be
37       created and initialized (see rtcInitIntersectContext).
38
39       When no intersection is found, the ray/hit data is not  updated.   When
40       an  intersection  is  found,  the hit distance is written into the tfar
41       member of the ray and all hit data is set, such as unnormalized  geome‐
42       try normal in object space (Ng hit member), local hit coordinates (u, v
43       hit member), instance ID (instID hit member), geometry ID  (geomID  hit
44       member),  and  primitive  ID (primID hit member).  See Section [RTCHit]
45       for the hit layout description.
46
47       If the instance ID was set (thus it is not equal to  RTC_INVALID_GEOME‐
48       TRY_ID),  the  instance  ID  corresponds  to the geometry ID of the hit
49       instance of the top-level scene, the geometry ID corresponds to the hit
50       geometry  inside  the  hit instanced scene, and the primitive ID corre‐
51       sponds to the n-th primitive of that geometry.
52
53       If  the  instance  ID  was  not  set  (thus  it  is  still   equal   to
54       RTC_INVALID_GEOMETRY_ID), the geometry ID corresponds to the hit geome‐
55       try inside the scene, and the primitive  ID  corresponds  to  the  n-th
56       primitive of that geometry.
57
58       The  implementation  makes no guarantees that primitives whose hit dis‐
59       tance is exactly at (or very close to) tnear or tfar are hit or missed.
60       If  you  want  to  exclude  intersections at tnear just pass a slightly
61       enlarged tnear, and if you want to include intersections at tfar pass a
62       slightly enlarged tfar.
63
64       The ray/hit structure must be aligned to 16 bytes.
65
66   EXIT STATUS
67       For  performance  reasons  this  function does not do any error checks,
68       thus will not set any error flags on failure.
69
70   SEE ALSO
71       [rtcOccluded1], [RTCRayHit], [RTCRay], [RTCHit]
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75                                                              rtcIntersect1(3)