Function renderPixel

tutorials/instanced_geometry/instanced_geometry_device.cpp:169–220

task that renders a single screen tile */

/* task that renders a single screen tile */
Vec3fa renderPixel(const TutorialData& data, float x, float y, const ISPCCamera& camera, RayStats& stats)
{
  /* initialize ray */
  Ray ray(Vec3fa(camera.xfm.p), Vec3fa(normalize(x*camera.xfm.l.vx + y*camera.xfm.l.vy + camera.xfm.l.vz)), 0.0f, inf);

  /* intersect ray with scene */
  RTCIntersectArguments iargs;
  rtcInitIntersectArguments(&iargs);
  iargs.feature_mask = (RTCFeatureFlags) (FEATURE_MASK);
  
  rtcTraversableIntersect1(data.g_traversable,RTCRayHit_(ray),&iargs);
  RayStats_addRay(stats);

  /* shade pixels */
  Vec3fa color = Vec3fa(0.0f);
  if (ray.geomID != RTC_INVALID_GEOMETRY_ID)
  {
    /* calculate shading normal in world space */
    Vec3fa Ns = ray.Ng;
    if (ray.instID[0] != RTC_INVALID_GEOMETRY_ID)
    {
      AffineSpace3fa xfm;
      rtcGetGeometryTransformFromTraversable(data.g_traversable,ray.instID[0],0.0f,RTC_FORMAT_FLOAT4X4_COLUMN_MAJOR,&xfm);
      Ns = xfmNormal(xfm,Ns);
      //Ns = xfmVector(data.normal_xfm[ray.instID[0]],Ns);
    }
    Ns = normalize(Ns);

    /* calculate diffuse color of geometries */
    Vec3fa diffuse = Vec3fa(1,1,1);
    if (ray.instID[0] != RTC_INVALID_GEOMETRY_ID)
      diffuse = data.colors[4*ray.instID[0]+ray.geomID];
    color = color + diffuse*0.5;

    /* initialize shadow ray */
    Vec3fa lightDir = normalize(Vec3fa(-1,-1,-1));
    Ray shadow(ray.org + ray.tfar*ray.dir, neg(lightDir), 0.001f, inf);

    /* trace shadow ray */
    RTCOccludedArguments sargs;
    rtcInitOccludedArguments(&sargs);
    sargs.feature_mask = (RTCFeatureFlags) (FEATURE_MASK);
    
    rtcTraversableOccluded1(data.g_traversable,RTCRay_(shadow),&sargs);
    RayStats_addShadowRay(stats);

    /* add light contribution */
    if (shadow.tfar >= 0.0f)
      color = color + diffuse*clamp(-dot(lightDir,Ns),0.0f,1.0f);
  }
  return color;
}

void renderPixelStandard(const TutorialData& data,
                         int x, int y,