Function renderPixel

tutorials/interpolation/interpolation_device.cpp:352–406

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 */
  rtcIntersect1(data.scene,RTCRayHit_(ray));
  RayStats_addRay(stats);

  /* shade pixels */
  Vec3fa color = Vec3fa(0.0f);
  if (ray.geomID != RTC_INVALID_GEOMETRY_ID)
  {
    /* interpolate diffuse color */
    Vec3fa diffuse = Vec3fa(1.0f,0.0f,0.0f);
    if (ray.geomID > 0)
    {
      auto geomID = ray.geomID; {
        rtcInterpolate0(rtcGetGeometry(data.scene,geomID),ray.primID,ray.u,ray.v,RTC_BUFFER_TYPE_VERTEX_ATTRIBUTE,0,&diffuse.x,3);
      }
      //return diffuse;
      diffuse = 0.5f*diffuse;
    }

    /* calculate smooth shading normal */
    Vec3fa Ng = ray.Ng;
    /*if (ray.geomID == 2 || ray.geomID == 3) {
      Vec3fa dPdu,dPdv;
      auto geomID = ray.geomID; {
        rtcInterpolate1(rtcGetGeometry(data.scene,geomID),ray.primID,ray.u,ray.v,RTC_BUFFER_TYPE_VERTEX,0,nullptr,&dPdu.x,&dPdv.x,3);
      }
      //return dPdu;
      Ng = cross(dPdu,dPdv);
    }*/
    Ng = normalize(Ng);
    color = color + diffuse*0.5f;
    Vec3fa lightDir = normalize(Vec3fa(-1,-1,-1));

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

    /* trace shadow ray */
    rtcOccluded1(data.scene,RTCRay_(shadow));
    RayStats_addShadowRay(stats);

    /* add light contribution */
    if (shadow.tfar >= 0.0f) {
      Vec3fa r = normalize(reflect(ray.dir,Ng));
      float s = pow(clamp(dot(r,lightDir),0.0f,1.0f),10.0f);
      float d = clamp(-dot(lightDir,Ng),0.0f,1.0f);
      color = color + diffuse*d + 0.5f*Vec3fa(s);
    }
  }
  return color;
}

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