RE: drawing 3D lines and OpenGL viewer

Hello John,

I have run your example and found no performance issue yet.

You can easily check the rate of your local video hardware by browsing the 3D scene generated by very your macro

http://root.bnl.gov/QtRoot/TileGeom.html

You will need to install the VRML Browser plug-in as described on that page to be able to render the *your* picture (and the other pictures too).

Best Regards

                         Valeri Fine

Brookhaven National Laboratory

Upton, NY 11973, USA

Phone: +1 631 344 7806

Fax: +1 631 344 4206

E-mail: fine_at_bnl.gov

-----Original Message-----
From: John Zoidberg [mailto:zohn.joidberg_at_gmail.com] Sent: Wednesday, February 07, 2007 8:22 AM To: Fine, Valeri
Cc: roottalk_at_root.cern.ch
Subject: Re: [ROOT] drawing 3D lines and OpenGL viewer  

Here's the program as it is now.
Some comments inside the program are unfortunately in french.

The goal is to visualize the solid angle of a cylinder seen from a gaussian source.

The program for displaying is display_3D.C. In fact, the title of my first mail is misleading because I also wanted to talk about a problem I had with openGL, but didn't talk about it in the end.

When I run display_3D under windows, I can use the GLviewer but not the X3D viewer.
Under Linux Ubuntu v6.10 (edgy eft), it's the opposite: I can run X3D, but not GLviewer.

Here are my system specs:

-video card: ATI Radeon IGP 345M with 64 MB memory
-448 RAM (=512-64)
-Pentium 4 with 2.4 GHz

Software:
-Under Linux Ubuntu: ROOT v5.09/01
-Under Windows: I don't know exactly right now, but probably ROOT v5.14/00 since I downloaded the latest from the root page not so long ago.

John

On 2/6/07, Fine, Valeri <fine_at_bnl.gov> wrote:

Hello John

> I am trying to draw lines in a 3D display.
> Currently, I am using a TPolyMarker3D object and the setpoint
function.
> The problem is that once I draw about 600000 or more points (3000
lines > ith 200 points), the display becomes very slow.

You numbers does not look horrible.
They are about two times as less as the average STAR Au-Au events. http://www.star.bnl.gov/STAR/comp/vis/OnLineEventDisplay.html http://www.star.bnl.gov/STAR/comp/vis/OnLineEventDisplay/AuAu200Animated

Small.gif

those we have no problem to visualize with STAR Event Displays, both "Online" and "Offline". Online means one has to update the screen in real time follow the data taking rate.

> I wanted to know if there already exists some function
> drawing 3D lines > which is better optimized.
> Because as I understand it, if the 3D viewer considers every point as
a 3D > object, he will calculate the rotation for every
> point instead of simply > rotating the "line".

What is your video hardware and entire hardware environment? I am wondering if the slowdown you observed is not OpenGL hardware fault. The problem is elsewhere.

Can you send (upload) me your data file and ROOT macro to play with.

Thank you

Mike   Received on Thu Feb 08 2007 - 00:39:19 CET