RE: drawing 3D lines and OpenGL viewer

From: Fine, Valeri <fine_at_bnl.gov>
Date: Tue, 6 Feb 2007 15:56:32 -0500


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 Tue Feb 06 2007 - 21:57:26 CET

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