Esempio n. 1
0
size_t generateVPLs(const Scene *scene, Random *random,
		size_t offset, size_t count, int maxDepth, bool prune, std::deque<VPL> &vpls) {
	if (maxDepth <= 1)
		return 0;

	static Sampler *sampler = NULL;
	if (!sampler) {
		Properties props("halton");
		props.setInteger("scramble", 0);
		sampler = static_cast<Sampler *> (PluginManager::getInstance()->
			createObject(MTS_CLASS(Sampler), props));
		sampler->configure();
	}

	const Sensor *sensor = scene->getSensor();
	Float time = sensor->getShutterOpen()
		+ 0.5f * sensor->getShutterOpenTime();

	const Frame stdFrame(Vector(1,0,0), Vector(0,1,0), Vector(0,0,1));

	while (vpls.size() < count) {
		sampler->setSampleIndex(++offset);

		PositionSamplingRecord pRec(time);
		DirectionSamplingRecord dRec;
		Spectrum weight = scene->sampleEmitterPosition(pRec,
			sampler->next2D());

		size_t start = vpls.size();

		/* Sample an emitted particle */
		const Emitter *emitter = static_cast<const Emitter *>(pRec.object);

		if (!emitter->isEnvironmentEmitter() && emitter->needsDirectionSample()) {
			VPL lumVPL(EPointEmitterVPL, weight);
			lumVPL.its.p = pRec.p;
			lumVPL.its.shFrame = pRec.n.isZero() ? stdFrame : Frame(pRec.n);
			lumVPL.emitter = emitter;
			appendVPL(scene, random, lumVPL, prune, vpls);

			weight *= emitter->sampleDirection(dRec, pRec, sampler->next2D());
		} else {
			/* Hack to get the proper information for directional VPLs */
			DirectSamplingRecord diRec(
				scene->getKDTree()->getAABB().getCenter(), pRec.time);

			Spectrum weight2 = emitter->sampleDirect(diRec, sampler->next2D())
				/ scene->pdfEmitterDiscrete(emitter);

			if (weight2.isZero())
				continue;

			VPL lumVPL(EDirectionalEmitterVPL, weight2);
			lumVPL.its.p = Point(0.0);
			lumVPL.its.shFrame = Frame(-diRec.d);
			lumVPL.emitter = emitter;
			appendVPL(scene, random, lumVPL, false, vpls);
			dRec.d = -diRec.d;

			Point2 offset = Warp::squareToUniformDiskConcentric(sampler->next2D());
			Vector perpOffset = Frame(diRec.d).toWorld(Vector(offset.x, offset.y, 0));
			BSphere geoBSphere = scene->getKDTree()->getAABB().getBSphere();
			pRec.p = geoBSphere.center + (perpOffset - dRec.d) * geoBSphere.radius;
			weight = weight2 * M_PI * geoBSphere.radius * geoBSphere.radius;
		}

		int depth = 2;
		Ray ray(pRec.p, dRec.d, time);
		Intersection its;

		while (!weight.isZero() && (depth < maxDepth || maxDepth == -1)) {
			if (!scene->rayIntersect(ray, its))
				break;

			const BSDF *bsdf = its.getBSDF();
			BSDFSamplingRecord bRec(its, sampler, EImportance);
			Spectrum bsdfVal = bsdf->sample(bRec, sampler->next2D());
			if (bsdfVal.isZero())
				break;

			/* Assuming that BSDF importance sampling is perfect,
				the following should equal the maximum albedo
				over all spectral samples */
			Float approxAlbedo = std::min((Float) 0.95f, bsdfVal.max());
			if (sampler->next1D() > approxAlbedo)
				break;
			else
				weight /= approxAlbedo;

			VPL vpl(ESurfaceVPL, weight);
			vpl.its = its;

			if (BSDF::getMeasure(bRec.sampledType) == ESolidAngle)
				appendVPL(scene, random, vpl, prune, vpls);

			weight *= bsdfVal;

			Vector wi = -ray.d, wo = its.toWorld(bRec.wo);
			ray = Ray(its.p, wo, 0.0f);

			/* Prevent light leaks due to the use of shading normals -- [Veach, p. 158] */
			Float wiDotGeoN = dot(its.geoFrame.n, wi),
				woDotGeoN = dot(its.geoFrame.n, wo);
			if (wiDotGeoN * Frame::cosTheta(bRec.wi) <= 0 ||
				woDotGeoN * Frame::cosTheta(bRec.wo) <= 0)
				break;

			/* Disabled for now -- this increases VPL weights
			   and accuracy is not really a big requirement */
			#if 0
				/* Adjoint BSDF for shading normals -- [Veach, p. 155] */
				weight *= std::abs(
					(Frame::cosTheta(bRec.wi) * woDotGeoN)/
					(Frame::cosTheta(bRec.wo) * wiDotGeoN));
			#endif

			++depth;
		}

		size_t end = vpls.size();
		for (size_t i=start; i<end; ++i)
			vpls[i].emitterScale = 1.0f / (end - start);
	}

	return offset;
}
Esempio n. 2
0
void MUONTriggerEfficiency(const char* filenameSim="galice_sim.root", 
                           const char* filenameRec="galice.root",  
                           Bool_t readFromRP = 0)
{
  
  // Set default CDB storage
  AliCDBManager* man = AliCDBManager::Instance();
  man->SetDefaultStorage("local://$ALICE_ROOT/OCDB");
  man->SetRun(0);
  
  // output file
  
  AliMUONMCDataInterface diSim(filenameSim);
  AliMUONDataInterface diRec(filenameRec);
  
  if (!diSim.IsValid())
  {
    cerr << "Cannot access " << filenameSim << endl;
    return;
  }
  
  if (!diRec.IsValid())
  {
    cerr << "Cannot access " << filenameRec << endl;
    return;
  }
  
  FILE* fdat = fopen("MUONTriggerEfficiency.out","w");          
  if (!fdat)
  {
    cerr << "Cannot create output file" << endl;
    return;
  }
  
  Int_t coincmuon,muonlpt,muonhpt;
  Int_t CoincMuPlus,CoincMuMinus;
  coincmuon=0;
  muonlpt=0;  
  muonhpt=0;
  
  Int_t nevents = diSim.NumberOfEvents();          
  
  for (Int_t ievent=0; ievent<nevents; ++ievent) 
  {   
    CoincMuPlus=0;
    CoincMuMinus=0;
    
    if (ievent%1000==0) printf("\t Event = %d\n",ievent);    
    
    // Hits
    
    Int_t NbHits[2][4];
    for (Int_t j=0; j<2; j++) 
    {
      for (Int_t jj=0; jj<4; jj++) 
      {
        NbHits[j][jj]=0;
      }
    } 
    
    Int_t ntracks = (Int_t) diSim.NumberOfTracks(ievent);
    
    for ( Int_t itrack=0; itrack<ntracks; ++itrack ) 
    {
      AliMUONVHitStore* hitStore = diSim.HitStore(ievent,itrack);      
      AliMUONHit* mHit;
      TIter next(hitStore->CreateIterator());
      
      while ( ( mHit = static_cast<AliMUONHit*>(next()) ) )
      {
        Int_t Nch = mHit->Chamber(); 
        Int_t hittrack = mHit->Track();
        Float_t IdPart = mHit->Particle();
        
        for (Int_t j=0;j<4;j++) 
        {
          Int_t kch=11+j;
          if (hittrack==1 || hittrack==2) 
          {
            if (Nch==kch && IdPart==-13 && NbHits[0][j]==0) NbHits[0][j]++; 
            if (Nch==kch && IdPart==13 && NbHits[1][j]==0) NbHits[1][j]++; 
          }       
        }
      }
    } // end track loop     
    
    // 3/4 coincidence
    Int_t SumNbHits=NbHits[0][0]+NbHits[0][1]+NbHits[0][2]+NbHits[0][3];
    if (SumNbHits==3 || SumNbHits==4) CoincMuPlus=1;
    
    SumNbHits=NbHits[1][0]+NbHits[1][1]+NbHits[1][2]+NbHits[1][3];
    if (SumNbHits==3 || SumNbHits==4) CoincMuMinus=1;
    
    if (CoincMuPlus==1 && CoincMuMinus==1) coincmuon++;         
          
    TString tree("D");
    if ( readFromRP ) tree = "R";
    
    AliMUONVTriggerStore* triggerStore = diRec.TriggerStore(ievent,tree.Data());

    AliMUONGlobalTrigger* gloTrg = triggerStore->Global();
    
    if (gloTrg->PairUnlikeLpt()>=1) muonlpt++;
    if (gloTrg->PairUnlikeHpt()>=1) muonhpt++;

  } // end loop on event  
 
  // calculate efficiency with as a ref. at least 3/4 planes fired
  Float_t efficiencylpt,efficiencyhpt;
  Double_t coincmu,lptmu,hptmu;  
  Float_t error;  
  coincmu=Double_t(coincmuon);
  lptmu=Double_t(muonlpt); 
  hptmu=Double_t(muonhpt); 

  // output
  fprintf(fdat,"\n"); 
  fprintf(fdat," Number of events = %d \n",nevents);  
  fprintf(fdat," Number of events with 3/4 coinc = %d \n",coincmuon);  
  fprintf(fdat," Nomber of dimuons with 3/4 coinc Lpt cut = %d \n",muonlpt);  
  fprintf(fdat," Number of dimuons with 3/4 coinc Hpt cut = %d \n",muonhpt);  
  fprintf(fdat,"\n");
  
  efficiencylpt=lptmu/coincmu;  
  error=efficiencylpt*TMath::Sqrt((lptmu+coincmu)/(lptmu*coincmu));  
  fprintf(fdat," Efficiency Lpt cut = %4.4f +/- %4.4f\n",efficiencylpt,error); 
 
  efficiencyhpt=hptmu/coincmu; 
  error=efficiencyhpt*TMath::Sqrt((hptmu+coincmu)/(hptmu*coincmu));          
  fprintf(fdat," Efficiency Hpt cut = %4.4f +/- %4.4f\n",efficiencyhpt,error);
      

  fclose(fdat);  
}