Fwd: Re: [Gate-users] Remote Visualization Problem
Martin L. Purschke
purschke at bnl.gov
Wed Nov 29 08:01:40 CET 2006
Hi Xiao,
I read this thread relatively late in the game. I think there are some
misconceptions. It is true that if you vnc to a windows machine, or to
your cell phone, or PDA, you actually get a representation of what the
native screen shows. With most Redhat-like Linux installations, this is
not the case. It is set up so that vnc starts a fresh X server that is
subject to all the window manager startup procedures it normally takes.
Since you mention the grey window, I assume you get the vanilla, what is
it, fvwm window manager, or just an xterm. And that vnc-specific X
server is not likely to have all the OpenGL attributes you need.
I run this show by just ssh'ing into the remote fast machine and
ssh-tunnel the display ("x11-forwarding") which is usually enabled by
default. If not, you can force it by adding -X to ssh, e.g.
ssh -X ...
and later put it into the local config file. The server has to support
it, too, check the remote machine's /etc/ssh/sshd_config for the
setting of the X11Forwarding entry.
As long as your local display where you issue the ssh on has all the
proper OpenGL capabilities, it will work. Just as a quick check, if you
just ssh into the remote machine as you describe in your very first
mail, look at the value of the DISPLAY variable which should be
something like localhost:10.0 or so. Then, on that remote shell, issue
glxinfo | grep -i open
Mine says:
> glxinfo | grep -i open
> libGL warning: 3D driver claims to not support visual 0x4b
> OpenGL vendor string: Tungsten Graphics, Inc
> OpenGL renderer string: Mesa DRI Intel(R) 852GM/855GM 20050225 x86/MMX/SSE2
> OpenGL version string: 1.3 Mesa 6.5.1
so you'll know if your display that you use has the required
capabilities. Maybe you can post the responses here.
Hope it helps,
Martin
xiaohan at uchicago.edu wrote:
> Hi Christian,
>
> Thank you so much for your reply. Unfortunately it still
> doesn't work here at all. I have local and remote machines
> installed with Fedora Core 4. vncserver+vncviewer is used.
> None of the three methods, local <-SSH->remote,
> local<-VNC->remote and local<-VNC->local, can start the
> visualization window. I always got the following response:
>
> PreInit> vis/open OGLSX
> /vis/open OGLSX
> 1 OpenGLStoredX scene handlers extanct.
> G4OpenGLViewer::G4OpenGLViewer couldn't open display.
> G4OpenGLStoredX::CreateViewer: error flagged by negative view
> id in G4OpenGLStoredXViewer creation.
> Destroying view and returning null pointer.
> ERROR in G4VisManager::CreateViewer during OpenGLStoredX
> viewer creation.
> No action taken.
>
> *** Break *** segmentation violation
> Generating stack trace...
> Abort (core dumped)
>
> I am not sure why this is so. Especially when I ran VNC on the
> remote machine itself. (BTW, the VNC-ed window is never the
> same as the actual screen that is monitored, but just a plain
> greyish window).
>
> Xiao
>
>
>
> ---- Original message ----
>> Date: Wed, 15 Nov 2006 08:21:03 +0800
>> From: Christian Wietholt <cwietholt at nhri.org.tw>
>> Subject: Fwd: Re: [Gate-users] Remote Visualization Problem
>> To: xiaohan at uchicago.edu
>> Cc: gate-users at lists.healthgrid.org
>>
>>
>> Hello Xiao,
>>
>> I just tried out the visualization via VNC over the network.
> I have on both
>> machines Debian Unstable installed. Both use XOrg 7.1. The
> remote machine has
>> the ATI OpenGL drivers installed, the local machine has the
> XOrg Radeon
>> drivers installed.
>>
>> As a VNC server I start x11vnc v.0.8.2 on the remote machine
> using the
>> following command from the local machine:
>>
>> ssh -L 5901:127.0.0.1:5901 10.71.10.1 'x11vnc -localhost
> -display :0'
>> As a VNC client I start TightVNC viewer v.1.2.9 on the local
> machine using the
>> following command:
>>
>> vncviewer -encodings "copyrect tight zrle hextile"
> 127.0.0.1::5901
>> Remote controlling my GATE simulation machine this way, I can
> get the OpenGL
>> visualization to work just fine. It might be a bit sluggish
> though.
>> I just tried exporting the visualization window onto the
> local desktop with
>> only little success. It managed to completely freeze my Desktop.
>>
>> I hope this will help you to get things to work.
>>
>> Christian
>> ---------- Forwarded Message ----------
>>
>> Subject: Re: [Gate-users] Remote Visualization Problem
>> Date: Wednesday 15 November 2006 00:08
>> From: xiaohan at uchicago.edu
>> To: Christian Wietholt <cwietholt at nhri.org.tw>
>>
>> Hi Christian,
>>
>> That's a good idea! I'm gonna have a try. Please keep me
>> posted about your result, too.
>>
>> Thanks,
>>
>> Xiao
>>
>> ---- Original message ----
>>
>>> Date: Tue, 14 Nov 2006 01:53:57 +0100
>>> From: Christian Wietholt <cwietholt at nhri.org.tw>
>>> Subject: Re: [Gate-users] Remote Visualization Problem
>>> To: xiaohan at uchicago.edu
>>>
>>> I would guess it is a problem with your OpenGL setup. Although,
>>> if you do VNC remote control, images of the remote desktop
>> are just
>>
>>> transfered in jpg. One way to find out is to compare the VNC
>> output
>>
>>> on the remote machine with the VNC output on the local
>> computer. I
>>
>>> believe the output over VNC works for me, but I will have a
>> look as
>>
>>> soon as I get a chance to.
>>>
>>> Christian
>>>
>>>> -----Ursprüngliche Nachricht-----
>>>> Von: xiaohan at uchicago.edu
>>>> Gesendet: 14.11.06 00:54:01
>>>> An: gate-users at lists.healthgrid.org
>>>> Betreff: [Gate-users] Remote Visualization Problem
>>>>
>>>>
>>>>
>>>> Hi Gaters,
>>>>
>>>> I can SSH to log on to, or use VNC to remotely control a PC
>>>> with GATE2.0 and run macro files in GATE to acquire data.
>>>> However, I could never visualize the constructed system from
>>>> an another computer. Is this a problem of GATE or OpenGL? Does
>>>> any one know how to enable visualization remotely?
>>>>
>>>> Thank you,
>>>> Xiao
>>>> _______________________________________________
>>>> Gate-users mailing list
>>>> Gate-users at lists.healthgrid.org
>>>> http://lists.healthgrid.org/mailman/listinfo/gate-users
>> -------------------------------------------------------
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--
Martin L. Purschke ; purschke at bnl.gov
; http://www.phenix.bnl.gov/~purschke
;
Brookhaven National Laboratory ; phone: +1-631-344-5244
Physics Department Bldg 510 C ; fax: +1-631-344-3253
Upton, NY 11973-5000 ;
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