Errors in drawing TEvePointSet markers in my event display

[rhowell]

I’ve been working through building my own event display with TEve, following closely the tutorials/eve/alice_vsd.C. I can display my geometry just fine in the 3D window as well as the multiview frames, but I am failing to plot any of my actual events.

My data format is atypical to any tutorial example; I’m essentially reading the x,y,z coordinates of LAr “hits” from std::vectors. I’m using TEvePointSet markers to display this information, but when it comes time to drawing them with

gEve->Redraw3D(kFALSE, kTRUE);

I get this error repeated over and over again, followed by intermittent errors with the TGLCamera

Error in <TGLPlane::Normalise>: trying to normalise plane with zero magnitude normal

Error in <TGLPerspectiveCamera::TGLCamera::FrustumCenter()>: frustum planes invalid

I’ve tried all different variations of gEve->Redraw3D() I can think of in my code, and nothing has worked. I should note when I do this the 3D geometry is not displayed at all either. I’ve pasted the relevant portions of my code below; any help would be greatly appreciated!

   TEveManager::Create();

   TEveGeoShape *gentle_geom = 0;

   auto file = TFile::Open("guitools/simple_geom.root");
   if (!file) return;
   auto gse = (TEveGeoShapeExtract*) file->Get("Gentle");
   gentle_geom = TEveGeoShape::ImportShapeExtract(gse, 0);
   file->Close();

   gEve->AddGlobalElement(gentle_geom);

   gMultiView = new MultiView;
   gMultiView->f3DView->GetGLViewer()->SetStyle(TGLRnrCtx::kOutline);

   gMultiView->SetDepth(-10);
   gMultiView->ImportGeomRPhi(gentle_geom);
   gMultiView->ImportGeomRhoZ(gentle_geom);
   gMultiView->SetDepth(0);

   // Final stuff
   //=============

   gEve->GetViewers()->SwitchColorSet();
   gEve->GetDefaultGLViewer()->SetStyle(TGLRnrCtx::kWireFrame);

   gEve->GetBrowser()->GetTabRight()->SetTab(1);

   MyMainFrame* main = new MyMainFrame(); // takes the place of make_gui(); in the tutorial, it's almost verbatim what exists in that function just with additional buttons/text boxes for my event display GUI.

   gEve->AddEvent(new TEveEventManager("Event", "ICARUS CAF Event"));
   GetSpectrumSelection(); // Fills the hit position vectors for the LAr hits
   gEve->Redraw3D(kTRUE); // Reset camera after the first event has been shown.
   LoadHits();
   gEve->Redraw3D(kFALSE,kFALSE);

void LoadHits()
{
    int c = 0;
    for (int sliceID : uniqueSliceIDs) { // loop through all unique slices in a neutrino spill

      int target = sliceID;
      std::vector<int> indices = findItems(SliceID[spill], target); //finds all the indices in my hits vector for this slice

      char slice[5];
      sprintf(slice,"%d",target);
      auto marker = new TEvePointSet(slice,indices.size()); // create the TEvePointSet object for each slice and reserve the number of points by the number of hits present in the slice
      marker->SetOwnIds(kTRUE);
      marker->SetElementName(slice);
      marker->SetMarkerSize(.5);
      marker->SetMarkerStyle(2);

      for (auto &e: indices) { // loop through all the hits in the slice
        if (SliceID[spill][e] != sliceID) { continue; } // I only want the hits for this slice
          marker->SetPoint(e,X[spill][e],Z[spill][e],Y[spill][e]); // set each point in the TEvePointSet for each hit
          marker->SetPointId(new TNamed(Form("Point %d", e), ""));
      }

      marker->SetMainColor(1+c);
      marker->IncDenyDestroy();
      marker->SetTitle(TString::Format("N=%d", marker->Size()));
      gEve->AddElement(marker);
      c++;
    }
    gEve->Redraw3D(kFALSE,kTRUE); // once all the TEvePointSet objects are filled per neutrino spill, plot them in my TEve
}

ROOT Version: v6_22_08d
Platform: linux-gnu
Compiler: linuxx8664gcc

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[rhowell]

I’ve gotten it working. I changed the instantiation to

 auto marker = new TEvePointSet();

And changed from doing SetPoint(…) to

marker->SetNextPoint(X[spill][e],Z[spill][e],Y[spill][e]);

Finally I moved the Redraw command inside the for loop. Hopefully this helps someone else in the future!