[Chimera-users] Flickering graphics

[Thomas Goddard]

Hi Murali,

  What kind of flickering do you see when moving maps in Chimera?
Does the surface appear shattered?  One nvidia graphics driver bug
I have seen causes the surface to appear broken into many triangles
instead of smooth while it is moved.  Or is it tearing that you see?
That is when the top half of the screen momentarily shows one position
for the map but the bottom shows a different one.  That happens because
you are moving the model and the redraw is not synchronized to the
vertical refresh of the display.  That is a graphics driver setting
problem.  Or does flicker mean it appears like every other frame is
black?

  Every possibility I can think of points to a graphics driver problem,
not a Chimera problem.  You can check on Linux what graphics driver you
are using with the glxinfo command:

	% glxinfo
	...
	OpenGL vendor string: NVIDIA Corporation
	OpenGL renderer string: Quadro4 500 GoGL/AGP/SSE2
	OpenGL version string: 1.5.2 NVIDIA 66.29
	...

The OpenGL renderer and version lines tell you the driver.  If it says
"Mesa" this means you have no driver installed and it is using software
rendering (no hardware acceleration).  Usually a new Linux system does
not have a graphics driver installed by default so you have to get the
driver from the NVidia web site.

	http://www.nvidia.com/content/drivers/drivers.asp

The latest Nvidia GeForce driver version is 9746.  The first step to
try to fix your problem is update to the newest driver.

	Tom

> Date: Fri, 22 Dec 2006 09:42:43 -0600
> From: "Murali Ayaluru" <mayaluru at gmail.com>
> To: goddard at cgl.ucsf.edu
> Subject: flickerings in model
> 
> Hi,
> 
> Greetings!
> 
> I am using Chimera (chimera-1.2304-linux.exe) in Linux (FC-6) environment.
> Basically I use this
> for visualizing the structures generated from EM. While moving the model
> (either vertical or horizontal) and also while rendering the volumes, I saw
> lot of flickering in the model.  Is there some parameter  I have to change
> to fix this problem?  The graphic card we use is nVidia GeForce 7300 LE. I
> don't have much experience in linux OS.  Any suggestions to fix the problem
> will be highly appreciated.
> 
> Thanks and have a nice day.
> 
> Regards,
> Murali