3D model or Event display at SWAN

Jupyter Notebooks
1

Dear SWAN experts,

currently, I am trying to use SWAN to prepare a HEP lecture.

I would like to show some 3D detetor models and event display later if possible.
Diogo has pointed me to one Jupiter example: https://nbviewer.jupyter.org/github/dpiparo/swanExamples/blob/master/notebooks/Geometry_Visualisation_cpp/Geometry_Visualisation_cpp.ipynb

However, if I do it in SWAN, the session crashes. The root file is only ~30K.
TGeoManager::Import("/eos/atlas/user/l/lezhang/Teaching/geometryfile/spaceStation.root");
gGeoManager->GetTopVolume()->Draw(“ogl”);

I also tried with other inputs which show the same problem.

At your conveience, can you tell me how to solve this problem?

Thanks a lot!

Cheers,

Lei

2

Hey Lei Zhang @lezhang ,

For issues like crashing kernel it is better to use SNOW (https://cern.service-now.com/service-portal/function.do?name=swan)

Can you try using swan006 with 16GB and try to reproduce the problem? I will also have a look into your logs. Lets follow up in SNOW.

Thanks!

4

Hi Lei,
Your code also crashes on me. Why do you do Draw(“ogl”) instead of just Draw() like in the Gallery example?
Maybe someone from ROOT could help here (@etejedor).
Diogo

5

Hi Piotr and Diogo,

thanks for your help again.

Indeed, if I remove “ogl”, it works! :smile: I copy that line from other script.
So, in this case, it is possible to do event display.

I also have another quesiton about the student account and will create another thread.

Thanks a lot!

Lei

6

Hi all,

sorry for coming back to this thread after so long.
I reallized that the “ogl” option is relevant actually.

In the standalone ROOT, if I use Draw(“ogl”), it will show a widget.
With it, I can do some options which is useful.
But, if I do “ogl” in SWAN, it will crash.

Do you have an idea how to get the widget in SWAN?

Thanks a lot!

Cheers,

Lei

7

P.S. in case needed, here is my code:

std::cout<<" hellow world “<<std::endl;
//TFile *inputfile = TFile::Open(”/eos/atlas/user/l/lezhang/Higgs/mumuH.root");
//TTree inputTree = (TTree)inputfile->Get(“ntEXC2_0001100”);
TGeoManager::Import("/eos/atlas/user/l/lezhang/Teaching/geometryfile/ShortTPC.gdml");
//TGeoManager::Import("/eos/atlas/user/l/lezhang/Teaching/geometryfile/spaceStation.root");
//below will crash
//gGeoManager->GetTopVolume()->Draw(“ogl”);
//below will not crash
gGeoManager->GetTopVolume()->Draw("");

8

Hi Lei,

The classic ROOT graphics are unfortunately not available in the notebook. You have basically two options: