[chimera-dev] Chimera binary code issue

[Tom Goddard]

Hi Jupiter,

   Chimera tries to use modern OpenGL features: shaders, vertex buffers, 
instancing, ....  It disables some of those features known to be buggy 
in mesa.  If you start chimera --debug-opengl you can disable more 
OpenGL features with a start-up dialog.

   You said in your first email that Chimera ran with "very poor 
performance when using mesa".  It would be helpful to give an explicit 
example (e.g. opening PDB yyyy the model rotates at about z frames per 
second).

   Does your X11 VNC render OpenGL using the client graphics driver?  It 
might just send the OpenGL to the client (ie. displaying) system in 
which case performance would depend on the graphics driver of that 
system.  Performance can be dismal in such a situation because OpenGL 
queries have to make a roundtrip across the network connection.

   Would you play a modern 3d video game on a virtual box over a VNC 
connection?  No.  And you're setting up an equally poor way of using 
Chimera, which depends on high performance 3d graphics.  The thing to do 
is advise your students and researchers to run this software on their 
machine.  If they are going to use it for more than a total of 1 hour in 
their lifetime, they would be better off.

     Tom

> Hi Tom,
>
> Thanks for your response.
>
> We are working for university research to provide OpenGL environment
> for students and researchers, the performance is not critical as long
> as the application can run relatively well. We have many other 3D
> applications which are all running fine with mesa xlib driver except
> Chimera which is the only application we have trouble with the mesa
> xlib driver.
>
> I know it is not Chimera problem, but we will appreciate any tips and
> advice to help us running Chimera on mesa xlib driver.
>
> Is there any OpenGL requirement for Chimera running on mesa, such as
> buffer size, depth buffer size...?
>
> Thank you.
>
> Kind regards.
>
> Jupiter
>
> On 3/9/13, Tom Goddard <goddard at sonic.net> wrote:
>> Hi Jupiter,
>>
>>    Chimera is linked against the OpenGL library on your system.  Whether that
>> uses Mesa or an Nvidia or ATI driver is up to your system -- it will not
>> help to recompile Chimera.  The only thing that could help is installing a
>> different system OpenGL driver.
>>
>>    You are trying to make your life difficult running Chimera on a virtual
>> machine and remote display with an X11 VNC client. Your problem is entirely
>> a computer configuration issue, nothing in Chimera can fix it.  You'd save
>> yourself a lot of frustration by running Chimera on an OS with a native
>> OpenGL driver.
>>
>> 	Tom
>>
>>
>> On Mar 8, 2013, at 1:12 AM, jupiter  wrote:
>>
>>> Hi,
>>>
>>> I have been reading Chimera document on Chimera web site and I am
>>> understanding that Chimera is better to run with hardware accelerator,
>>> but we don't have GPUs in our virtual machines, we have to use mesa
>>> and we are using xlib-glx driver for remote VNC connection.
>>>
>>> One major issue I am currently investigating is that the binary
>>> Chimera code can perform 3D rotation in mesa DRI driver, but very poor
>>> performance when using mesa xlib-glx driver on CentOS 6. Please
>>> correct me my following assumptions and options to rectify the
>>> problem:
>>>
>>> (1) Binary code could be hard linked with mesa DRI driver, the
>>> solution is to remove the hard link, or replace some libraries.
>>>
>>> (2) Chimera may not be able to run on mesa xlib-glx driver at all, no
>>> possible workarounds, no solution.
>>>
>>> (3) Chimera can be used with xlib-glx driver if we can build Chimera
>>> source code with mesa xlib-glx driver.
>>>
>>> I understand you don't encourage people to build Chimera from source
>>> code, nor do I wish. But if that is the only choice which can fix the
>>> problem, would you please point me instructions and procedures how to
>>> build the source code on Linux? I've looked at README.bootstrap from
>>> svn source code, but
>>>
>>> Thank you.
>>>
>>> Kind regards.
>>>
>>> Jupiter
>>> _______________________________________________
>>> Chimera-dev mailing list
>>> Chimera-dev at cgl.ucsf.edu
>>> http://www.rbvi.ucsf.edu/mailman/listinfo/chimera-dev
>>>
>>