Propagated Eve tracks not showing up unless I use the editor

jeremym · September 4, 2020, 11:24pm

I have an odd problem with Eve where tracks I am propagating do not show up unless I use the “Edit Propagator” button in the GUI.

The code where I add the tracks to my scene is in this method:

github.com

JeremyMcCormick/hps-event-display/blob/master/src/EventObjects.cxx#L152


        element->SetElementTitle(Form("Simulated Calorimeter Hit\n"
                "(x, y, z) = (%.3f, %.3f, %.3f)\n"
                "Time = %f, Energy = %E, Contribs = %d",
                x, y, z, hitTime, energy, hit->getNMCContributions()));
        elements->AddElement(element);
    }
    return elements;
}

// REF: Druid src/BuildMCParticles.cc
TEveCompound* EventObjects::createMCParticles(EVENT::LCCollection* coll,
                                              EVENT::LCCollection* simTrackerHits) {

    TEveCompound *mcTracks = new TEveCompound();
    mcTracks->SetMainColor(kRed);
    mcTracks->OpenCompound();

    TEveTrackPropagator* propsetCharged = new TEveTrackPropagator();
    std::cout << "[ EventObjects ] Setting up mag field with bY: " << bY_ << std::endl;
    propsetCharged->SetMagFieldObj(new TEveMagFieldConst(0.0, bY_, 0.0));
    propsetCharged->SetDelta(0.01); // Step size

This uses an experiment specific data binding (LCIO), but I am setting up the tracks in the typical way using the standard classes.

I had thought perhaps the values of Max R and Max Z were the problem, as tracks will not propagate if they are too low. But that doesn’t seem to be it. When I change the slides at all, the tracks immediately show up in the scene, but I cannot get them to render as I switch from event to event, even with hard coded R/Z settings in my code that should be reasonable.

Any idea why this might be the case that they don’t show up by default in a redraw by they get drawn when I use the editor?

The hits and other objects are displaying just fine, and a full redraw does seem to be occurring as I step through events, so basically things are functioning fine except for this.

matevz · September 8, 2020, 6:18pm

Hi,

I think you need to call TEveTrack::MakeTrack() (or TEveTrackList::MakeTracks() if you put the tracks into a list). The propagator knows which tracks it’s supposed to control so this gets called on change of propagator parameters.

Cheers,
Matevz

jeremym · September 9, 2020, 4:41pm

Calling MakeTrack() worked. Thank you!

system · September 23, 2020, 4:51pm

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