1. Visualization of the ROOT 3D class objects with Open Inventor-like viewers V. Fine (BNL) A. Kulikov (JINR Dubna) M. Panebrattsev (Dubna University) A. Kulikova (MEPHI Moscow)

2. Dec 3, 2003ACAT032 preface This work was done by a group of summer students from Moscow Engineering and Physics Institute (MEPHI), University of Dubna of STAR Group at JINR. This group is involved in data analysis of STAR experiment at BNL. The experiment deals with a huge amount of data. It requires a new approaches to be introduced.

3. Dec 3, 2003ACAT033 Why do we need it. There is a strong need to introduce new ideas and methods to debug the simulation and track reconstruction software within STAR framework. The good portion of computational force (and price) of the modern computer, first of all so-called Desktop PC, belongs its sophisticated video card with advanced 3D accelerators. So far this vast power did not play any major role in the High Energy Physics research due lack of the software that can be feed by the HEP data. That can be done by developing the class library to allow using the commercial quality 3D viewers like "Open Inventor" both stand-alone as well as a built-in ROOT 3D viewer to make the cutting / highlighting / selecting pieces of the detectors and events fruitful and ease. It makes possible to see the inner parts of the detector, which usually covered by outer parts. That would create the impressive pictures of events and the detail views of the detectors facilitating the design, simulation and data analysis and representation the huge amount the information flooding the moder n HEP experiments

4. Dec 3, 2003ACAT034 From AGE Geometry Specification to Open Inventor format (IV) Originally the detector geometry is defined by the special language called AGE (Geometry Specification Langugae). We solve the problem of the C++ object visualisation by converting it to the.iv format. So You can easily view and manipulate the detector geometry. AGE (geometry specification language) Macro preprocessor Fortran GEANT3 compile GEANT3 Zebra structure C++ object TVolumeView.fz files Converter to iv format.root files Iv files See next slide

5. Dec 3, 2003ACAT035 Convertion of zebra banks to ROOT C++ objects ftp://root.cern.ch/root2k/pavelR2000.ppt

6. Dec 3, 2003ACAT036 ROOT Class library for converting TVolumeView objects to the.iv format. We developed ROOT class library which converts the ROOT TVolumeView object to the.iv file. So it is possible to use the standard 3dViewer to see the detector geometry. The TVolumeView object is a tree of rudimentary shapes described by TBRIK, TTUBE, etc. classes. So our library mainly consists of the special convertor classes for each of this shape (TIVBrik, TIVTube, etc.). For the round objects (TTube, TCone, etc.) it is possible to set the “CutNumber” which represents what part of these objects you want to see. Usually it is not necessary to see all parts of the detector, so you can define the depths of the objects in a tree which you want to see.

7. Dec 3, 2003ACAT037 ROOT TShape classes TBRIK TPARA TGTRA TTRAP TTRD1 TTRD2 TTUBE TCONE TTUBS TCONS TPCON TPGON

8. Dec 3, 2003ACAT038 Convertor Class Library TIVFile TIVBrik TIVPConTIVShape TIVTube TIVCone TIVTubs TIVCTub TIVTrd1 TR2iv

9. Dec 3, 2003ACAT039 TVolumeView into.iv format conversion example. { TR2iv riv(ATLS, 3, 4); // ATLS – Pointer to the TVolumeView object // 3 and 4 is the depth interval in which shapes will be converted TIVShape::SetCut(1) // Sets the CutNumber for the round objects (1 – whole object, 2- half object) riv.Draw(“ATLAS.iv"); // Writes TVolumeView *ATLS into the ATLAS.iv file. }

10. Dec 3, 2003ACAT0310 Examples … TR2iv riv(ATLS, 3, 4); TIVShape::SetCut(1); … TR2iv riv(ATLS, 3, 4); TIVShape::SetCut(2) … In this two pictures you can see how the outer cylinder was cut.

11. Dec 3, 2003ACAT0311 Detail view of inner part of ATLAS

12. Dec 3, 2003ACAT0312 Examples … TR2iv riv(ATLS, 4, 4); TIVShape::SetCut(2); … In this case several detector parts were removed manually in the 3d Viewer Here we set the bigger depth level so the outer cylinders disappeared. Than the unnecessary parts was removed using the viewer features.

13. Dec 3, 2003ACAT0313 Events It is also possible to include tracks to the detector geometry. STAR Detector with real tracks

14. Dec 3, 2003ACAT0314 Results Several convertor classes were created. It is possible to download the class library and example root file containing ATLAS geometrythe class libraryexample root file containing ATLAS geometry In our future plan is to create whole set of convertor classes and some additional features which can help to get a better image of the detector. For example two plane cut of the detector. All the suggestions and questions you can send to the mpanebr@sunhe.jinr.ru mpanebr@sunhe.jinr.ru

15. Dec 3, 2003ACAT0315 STAR Simulation (ppt) (html): Pavel Nevski (ftp://root.cern.ch/root2k/pavelR2000.ppt)ftp://root.cern.ch/root2k/pavelR2000.ppt STAR Framework and Visualisation (ppt) (html): Valery Fine ftp://root.cern.ch/root2k/StarFrameWorkAb d3D.pptftp://root.cern.ch/root2k/StarFrameWorkAb d3D.ppt