Function addInstances

tutorials/multi_instanced_geometry/scene.cpp:140–167

* Add instances to a scene. * This function also writes normal transforms to the given map. */

 * This function also writes normal transforms to the given map.
 */
void addInstances(RTCDevice device,  
                  RTCScene scene,
                  RTCScene exemplar,
                  const Instances& instances,
                  LinearSpace3fa* normalTransforms)
{
  for (unsigned int i = 0; i < instances.numInstances; ++i)
  {
    const unsigned int idx = 3*i;
    auto M = buildMatrix(instances.localX + idx, 
                         instances.localY + idx,
                         instances.localZ + idx,
                         instances.position + idx);

    RTCGeometry geom = rtcNewGeometry(device, RTC_GEOMETRY_TYPE_INSTANCE);
    rtcSetGeometryInstancedScene(geom, exemplar);
    rtcSetGeometryTimeStepCount(geom, 1);
    rtcSetGeometryTransform(geom,
                            0,
                            RTC_FORMAT_FLOAT4X4_COLUMN_MAJOR,
                            reinterpret_cast<float*>(&M));
    rtcCommitGeometry(geom);

    rtcAttachGeometryByID(scene, geom, i);
    rtcReleaseGeometry(geom);
    normalTransforms[i] = transposed(rcp(M.l));
  }
}

/*
 * Initialize the main scene. Note that we store complex geometry in