iClu = iClu%1000; //GetHMPIDcluIdx -> 1e+6*ch + 1e+3*clusize + cluIdx;
point.SetVolumeID(AliGeomManager::LayerToVolUID(AliGeomManager::kHMPID,iCham));//layer and chamber number
TClonesArray *pArr=(TClonesArray*)(*fClu)[iCham];
+ if(!pArr) return kFALSE;
AliHMPIDCluster *pClu=(AliHMPIDCluster*)pArr->UncheckedAt(iClu);//get pointer to cluster
+ if(!pClu) return kFALSE;
Float_t xyz[3];
pClu->GetGlobalXYZ(xyz);
Float_t cov[6];