Re: [Visualpython-users] From newbie: major performance woes

[Jiang Q. <jq...@ph...>]

On Wed, Nov 07, 2007 at 10:46:36PM -0500, Bruce Sherwood wrote:
> The URL to the program was omitted from the previous note:
> 
> 	http://physics.harvard.edu/~jqian/vector.py)
> 
> I don't see any of the crashes on Ubuntu that you see. You might try 
> updating your graphics card driver, a frequent source of problems of the 
> kind you describe.
I'm using the latest proprietary graphic driver fglrx. At the end of the 
email the I'll put the output of my glxinfo. As I said, all the crazy 
openGL 3D stuff like stellarium, googleearth and the stable version of 
visual runs just fine. So I'm skeptical that my openGL implementation is 
at fault---so far the beta version of visual is the only openGL 
application that does not work on my rig.
> 
> I do however see the slowness (even with shininess=0 and the 
> experimental scene.lod=-6), and this is one of the issues in the beta 
> version that needs to be addressed. I'm stunned that in the production 
> version of Visual rotation is smooth, as there are more than 9000 spheres!
Well, I'll have to say 9000 spheres are not a good measure for the 
rendering, because after all what we see is a two dimensional projection 
of a 3D pack, and if we view from the outside, we see around 9000^(2/3) 
of about 400 spheres on the surface as the spheres are packed pretty 
tightly and cover each other. But still, it's quite when we see the 
surface.  However, what really helps me is the fact that I'm able to 
zoom into the system and rotate to maneuver and "walk" inside the 
system. When I do that, my system is slower but still usable in the 
production version. So I'm happy about it, no doubt, and it'll really be 
wonderful if I can deliver transparency with an acceptable performance 
cost. 

BTW, is there a way to install both the production and beta version and 
to choose them from runtime? I set the directory of the production 
system to be /usr/local and the beta to be /usr when configuring, but it 
seems that the beta doesn't like the presence of production system and 
crash if I don't remove the /usr/local packages.
Jiang
> 
> I'm particularly grateful to have this example program, because it has 
> uncovered a bizarre bug. I modified all the spheres to have shininess=0, 
> in the hopes that this would improve performance. To my great surprise, 
> the spheres continued to have specular highlights. Then I found that 
> only if I comment out the initial lines that create boxes, the spheres 
> lose their shininess. This is a very strange interaction.
> Bruce Sherwood



glxinfo

direct rendering: Yes
server glx vendor string: SGI
server glx version string: 1.2
server glx extensions:
    GLX_ARB_multisample, GLX_EXT_visual_info, GLX_EXT_visual_rating,
    GLX_EXT_import_context, GLX_OML_swap_method, 
GLX_SGI_make_current_read,
    GLX_SGIS_multisample, GLX_SGIX_fbconfig
client glx vendor string: SGI
client glx version string: 1.4
client glx extensions:
    GLX_ARB_get_proc_address, GLX_ARB_multisample, 
GLX_EXT_import_context,
    GLX_EXT_visual_info, GLX_EXT_visual_rating, 
GLX_MESA_allocate_memory,
    GLX_MESA_copy_sub_buffer, GLX_MESA_swap_control,
    GLX_MESA_swap_frame_usage, GLX_OML_swap_method, 
GLX_OML_sync_control,
    GLX_SGI_make_current_read, GLX_SGI_swap_control, GLX_SGI_video_sync,
    GLX_SGIS_multisample, GLX_SGIX_fbconfig, GLX_SGIX_pbuffer,
    GLX_SGIX_visual_select_group, GLX_EXT_texture_from_pixmap
GLX extensions:
    GLX_ARB_get_proc_address, GLX_ARB_multisample, 
GLX_EXT_import_context,
    GLX_EXT_visual_info, GLX_EXT_visual_rating, GLX_OML_swap_method,
    GLX_SGIS_multisample, GLX_SGIX_fbconfig
OpenGL vendor string: ATI Technologies Inc.
OpenGL renderer string: ATI MOBILITY RADEON X300
OpenGL version string: 2.0.6958 Release