CHEP-03 UCSD La Jolla124/03/2003 The PERSINT Visualization Program for the ATLAS Experiment D....

24/03/2003CHEP-03 UCSD La Jolla 1

The PERSINT Visualization Program

for the ATLAS Experiment

D. PomarèdeCEA/DSM/DAPNIA/SEDI

CHEP 24/03/2003 2D. Pomarède, CEA/DAPNIA/SEDI

OUTLINE

•INTRODUCTION

•DESIGN

•GENERAL PRESENTATION

•APPLICATIONS

– VISUALIZATION OF GEOMETRY

– EVENT DISPLAY

•PROSPECTS


INTRODUCTION

•PERSINT (PERSpectively INTeracting) is designed for the three-

dimensional representation of objects and for the interfacing to a

variety of applications, in a fully interactive way.

•It has the following features :

– 3D representation of objects in full volumes or wire frames

– Computation of hidden faces

– Spatial navigation with real-time displacements

– Focal length adjustable at will (from isometry to wide-angle)

– Interfaces and access to applications

– Maximum interactivity

– Documentation


INTRODUCTION

•PERSINT was originally developed as a tool for debug-

ging and optimizing the ATLAS Muon pattern recognition

and track reconstruction algorithm (MUONBOX)

•PERSINT is now used routinely for :– Visualization of detector geometries :

• AMDB (ATLAS Muon DB)

• AGDD-XML (ATLAS Generic Detect. Description)

– Event Display (hits & reconstruction objects)

• Complex Monte Carlo Events

• ONLINE EVD in TestBeams

– Other :

• Magnetic field, Level-1 Trigger Logic (Muon), …


DESIGN

•Core in F90

– Usage of Modules, with procedure interfaces

– Polymorphism

– Recursive functions

– Dynamic arrays

– Allocate (local memory management)

– Pointers

– String operations

– Array manipulations

– Free source forms


DESIGN

•GRAPHICS Interface : HIGZ

•In general, use of CERNLIBS

•26000 lines of code

•Part of the Saclay Muon Software suite, and as such

interfaced directly to :

– AMDBSIMREC (geometry database) 13000 lines

– BFIELDDTB (magnetic field database) 3500 lines

– MUONBOX (track reconstruction) 58000 lines


DESIGN

•Highly modular, organized in patches

– e.g. XML section

•Computation of volumes, hidden faces

– based on analytical computation of facets’ edges

– Highlight intersections, detect clashes

– Boolean operations

•Lighting intensity effects on volume facets

•Designed to operate in standalone mode, keeping the

possibility of integration in frameworks


PRESENTATION OF THE PROGRAM

•General layout

•Navigation

•Perspective

•Event Display of complex Monte Carlo events

•Online Event Display

•Interface to AGDD-XML

•Interface to Level-1 Trigger

•Interface to Magnetic Field


GENERAL LAYOUT

COMMAND WINDOW

NAVIGATOR

DISPLAY WINDOW


THE NAVIGATOR

MIDDLE-CLICK : GET ONLINE HELP

LEFT CLICK : DEFINE MOVEMENTS INVOKE INTERFACES TO APPLICATIONS

INVOKE INTERFACES

AMDBAGDD-XMLEVD

DISPLACE VIEWER/VIEWED POINTS

FOCAL LENGTH

PROJECTIVE VIEWS

SWITCH WIRE/FULL VOLUMES


NAVIGATION•Two options :

– use the navigator (step-by-step movements)– real-time continuous displacements

move up

move down

moveright

moveleft

movein

moveout

Drag cursor :

Left button pressed downfor rotation

Middle buttonpressed down for forward/backwarddisplacements


FOCAL LENGTH

•Normal view : 35 mm


FOCAL LENGTH

•Infinite F.L. (isometric view)


FOCAL LENGTH

•Wide angle (few mm F.L.)


FOCAL LENGTH

•Projections

X-view Z-view

Also available : -view, Y-view, real-time lateral displacements


EVENT DISPLAY OF MONTE CARLO DATA•Example of event from ATLAS Data Challenge 1, single-muon with high lumi pile-

up, safety factor 5 on cavern component. Interactive track reconstruction (MUONBOX).


EVENT DISPLAY OF MONTE CARLO DATA


EVENT DISPLAY OF MONTE CARLO DATA•Example of event from ATLAS Data Challenge 1, single-muon with high lumi pile-up,

safety factor 5 on cavern component. Interactive track reconstruction (MUONBOX).


EVENT DISPLAY OF MONTE CARLO DATA


ONLINE EVENT DISPLAY

•H8-2002 Muon Testbeam : 6 Barrel chambers + 5 Endcap chambers

•Implementation in the online software using the Monitoring Factory

•Proved useful in commissioning of detectors and understanding of events

GEthFEth

PC ROS 1

GEthFEthPCROS 2

GEth

FEth

GEth SFI SFO

PC

Switch

PERSINT reads the Event at the SFI level…

…and displays it


INTERFACE TO AGDD-XML•Example : description of dead matter (used by MUONBOX for M.S.,…)•Display of event hits : generic usage (Inner Trackers, Calorimeters, …)•Supports all Boolean operations


BOOLEAN VOLUME OPERATIONS

•PERSINT supports

boolean volume ope-

rations

•Three basic

operations:

– Addition

– Subtraction

– Intersection

•This allows the

creation of very complex

3D objects from simple

ones


INTERFACE TO LEVEL-1 TRIGGER

•Visualization of L1 Trigger objects : RoI, PAD Logic, Coinci-dence Windows, supervision of Coincidence Matrices, …

•Example : Higgs to four muons event


INTERFACE TO MAGNETIC FIELD

Dedicated Interface for :

•Visualization of the magnetic field map

•2D or 3D lattice•Visualization of

magnet elements


PERFORMANCES

•Navigation with full volumes– On a 2.8 GHz Pentium 4

– 0.65 sec to compute and display 2300 volumes / 15000 facets of the Muon precision chambers system

– Real-time displacements are fluid (> 10 views per second) for a number of volumes < 400

•Event Scan on Testbeam Data– Display events in loop with 6 MDT chambers and ~ 20 hits

– 0.02 sec/event for bare event display

– 0.20 sec/event with track reconstruction


AVAILABILITY OF THE CODE

•PERSINT Web Page

– http://cern.ch/Atlas/GROUPS/MUON/persint.html

•AFS Location

– /afs/cern.ch/atlas/offline/external/Persint

•Documentation updated with every release


PROSPECTS

•DISCUSSION ON THE DESIGN

– ADVANTAGES :

• User can download a single executable binary; no dll, no

fancy APIs to install;

• Efficient even if operated remotely (e.g on remote clusters

from a X-terminal)

– DISADVANTAGES :

• Limited graphics interface (256 colors, …)

• Does not profit from high performance capabilities of

graphics cards when operated locally on PCs (Z-buffer).


PROSPECTS

•Planned developments :

– Integration in the ATHENA reco/analysis framework

=> useful to debug events

– Possibility to launch EVD from the ASK Interactive

toolkit

– Migration to OpenGL ?

– Integrate some parts in ROOT (calculus of hidden

faces, intersecting volumes, …) ?


PROSPECTS

•Planned utilization :

– Online EVD in the H8-2003 Muon Testbeam

– Online EVD in the H8-2004 Combined Testbeam

– Commissioning of ATLAS : participation in the

debug of the detector (cosmics runs, calibration

runs, …)

– ATLAS Online EVD for monitoring of data-taking

CHEP-03 UCSD La Jolla124/03/2003 The PERSINT Visualization Program for the ATLAS Experiment D....

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