Function initializeScene

tutorials/minimal/minimal_sycl.cpp:127–199

* Create a scene, which is a collection of geometry objects. Scenes are * what the intersect / occluded functions work on. You can think of a * scene as an acceleration structure, e.g. a bounding-volume hierarchy. * * Scenes, like devices, are reference-counted. */

 * Scenes, like devices, are reference-counted.
 */
RTCScene initializeScene(RTCDevice device, const sycl::queue& queue)
{
  RTCScene scene = rtcNewScene(device);

  /* 
   * Create a triangle mesh geometry, and initialize a single triangle.
   * You can look up geometry types in the API documentation to
   * find out which type expects which buffers.
   *
   * We create buffers directly on the device, but you can also use
   * shared buffers. For shared buffers, special care must be taken
   * to ensure proper alignment and padding. This is described in
   * more detail in the API documentation.
   */
  RTCGeometry geom = rtcNewGeometry(device, RTC_GEOMETRY_TYPE_TRIANGLE);
  
  float* vertices = alignedSYCLMallocDeviceReadOnly<float>(queue, 3 * 3, 16);

  rtcSetSharedGeometryBuffer(geom,
                             RTC_BUFFER_TYPE_VERTEX,
                             0,
                             RTC_FORMAT_FLOAT3,
                             vertices,
                             0,
                             3*sizeof(float),
                             3);

  unsigned* indices = alignedSYCLMallocDeviceReadOnly<unsigned>(queue, 3, 16);
  
  rtcSetSharedGeometryBuffer(geom,
                             RTC_BUFFER_TYPE_INDEX,
                             0,
                             RTC_FORMAT_UINT3,
                             indices,
                             0,
                             3*sizeof(unsigned),
                             1);

  if (vertices && indices)
  {
    vertices[0] = 0.f; vertices[1] = 0.f; vertices[2] = 0.f;
    vertices[3] = 1.f; vertices[4] = 0.f; vertices[5] = 0.f;
    vertices[6] = 0.f; vertices[7] = 1.f; vertices[8] = 0.f;

    indices[0] = 0; indices[1] = 1; indices[2] = 2;
  }

  /*
   * You must commit geometry objects when you are done setting them up,
   * or you will not get any intersections.
   */
  rtcCommitGeometry(geom);

  /*
   * In rtcAttachGeometry(...), the scene takes ownership of the geom
   * by increasing its reference count. This means that we don't have
   * to hold on to the geom handle, and may release it. The geom object
   * will be released automatically when the scene is destroyed.