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Re: [Visualpython-users] From newbie: major performance woes
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From: Bruce S. <Bru...@nc...> - 2007-11-08 03:46:26
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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 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! 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 Jiang Qian wrote: > On Wed, Nov 07, 2007 at 10:11:32AM -0500, Bruce Sherwood wrote: >> The beta version is called the beta version because there are problems >> with it, and it's helpful to have your report of what doesn't work; >> there have been almost no reports from Linux users. I normally work on >> Windows but have tested the Linux beta version against a variety of >> applications. I had concluded that the beta version mostly works okay on >> Linux, while there are serious bugs on Windows. You're reporting that it >> isn't okay even on Linux, which I was not aware of. > In addition to the testing I reported to be not working properly, the > stonehenge example crash the beta immediately after launch. And hanoi.py > shows a lot of artefacts and becomes slow and pretty much unusable. >> My own testing was done on a more recent version of Ubuntu, though that >> seems an unlikely issue, and your hardware is certainly adequate >> (presumably your 1.86MHz processor is a typo; it must be 1.86GHz). > Yes of course that's a typo. Now one worry about my ancient ubuntu is > that my libboost version is still 1.31. Would that be a problem? >> Because I'm trying to get into working on the problems with the beta >> version myself, it could be helpful if you would send me an example of a >> program where interactivity is compromised, to add to my suite of test >> programs. > Please find in this URL a program of visualizing 9288 spheres in a 27 > unit cell random non-overlapping distributions. Colors marks the grain > boundaries. It the stable version, I can rotate the pack at will, zoom > in, etc. This is so even when I improve the sphere rendering smoothness > by decreasing the two if(size <0.02) if(size<=0.125)... lines to 0.004 > and 0.125 respectively. The stock stable 3.2.9 presumably would be even > faster. > > However, in the beta version, I cannot rotate the pack at will, > interactivity becomes inadequate. >> There isn't a simple patch to make the production version have >> transparency. There was a major change in the fundamental architecture >> of Visual to make transparency a possibility. >> >> As stated in the description of the points object, these are circles or >> squares, not spheres, of particular use in plotting graphs. They may or >> may not be of any use to you. I would think that they're a lot faster >> than spheres. > Too bad. >> The late Arthur Siegel did experiment a bit with specifying the level of >> detail for the rendering of spheres. There is an undocumented attribute >> of the "display" object: >> >> scene.lod = -3 # range is -6 (low level of detail) to 0 (high) >> sphere() >> >> I don't like having negative values for "level of display" (lod), so >> think of this as very experimental, but it will let you try some things. >> Alternatively, since you evidently have a lot of experience, you could >> make changes of your own to the internal workings of Visual to >> experiment with the issues. Thanks much for your report. > Unfortunately I really kind of need to actually use visual to help me > intuitively grasp some problems in my research, so I can't afford to > play it too much. So I decided to forgo transparency for now and revert > back to the stable version. Thanks for the help, though. > Jiang >> Bruce Sherwood >> >> Jiang Qian wrote: >>> Hi: >>> Sorry about the confusing subject line of my last email. I did >>> manage to compile the beta, I just have major performance problem. >>> I took a look at the code of sphere.cpp, and notice there's >>> discussion about levels of details. I wonder, however, are all that >>> exposed to the user? Is there anyway I can reduce the level of details >> >from my script? Or if that's not possible, is it possible to in fact >>> change the code manually and recompile? >>> Another issue that may or may not have anything to do with my >>> performance woes. There are several demos in the example directory does >>> not run properly in my installation. Drape shows only a rod. Double >>> pendulum is way slower than in 3.4, Hanoi shows artifacts whenever I >>> move a ring. I'm beginning to think there might be something wrong with >>> my beta installation. How can I check? >>> Thanks in advance for your help. >>> Jiang >>> >>> On Wed, Nov 07, 2007 at 01:35:57AM -0500, Jiang Qian wrote: >>>> Hi all: >>>> I'm new to this list. I installed the stable visual-3.2.9 and it >>>> worked great. But I really would like to to get the transparency to >>>> work. So I installed visual 4.beta16. I jumped through all sorts of >>>> hoops, and finally got it to work. The transparency works quite well. >>>> But I have serious performance issue. >>>> I mainly use visual to visualize packed spheres, and small >>>> particles inside the spaces between them. In visual 3.2.9, a system with >>>> a few hundred spheres packed inside a cube works very smoothly: I can >>>> rotate, zoom at will with middle and right button. By combining the two, >>>> I can essentially "walk" into the sphere packs.(The spheres rendered are >>>> not perfectly smooth, but I manually changed some lines in the source >>>> code to make the smoothness ok). It all works fine, the only thing I >>>> miss is transparency. >>>> However, in visual 4.beta16, using identical code(with *no* >>>> transparency yet), I get a spectacularly smooth and well lit spheres, >>>> but the tradeoff seem to be heavy performance penalty: I can barely zoom >>>> and move, the rotation is slow. Interactive zooming and rotation is the >>>> key reason why I use visual: otherwise I can just render things in >>>> povray. Needless to say, I would like to find a way to trade away some >>>> of the more spectacular visual effects to have better interactive >>>> performance. >>>> I tried to look through the documentation of beta, but there >>>> aren't too much info about performance tuning. The only thing I found is >>>> to set shininess to 0, which helps marginally at best. >>>> What other tricks can I use to improve interactive performance? >>>> For example, can I tune the smoothness of the spheres? Sometimes my cpu >>>> usage is not even fully 100%, but dragging, rotating and zooming the >>>> image is still very slow. >>>> It'll really be a shame if I have to revert to the old version >>>> due to performance issue. There must be a way to balance performance >>>> and effects. >>>> In a related issue. I also need to render particles between the >>>> spheres in the pack. In the old version, I basically render them as >>>> smaller spheres. But in the new version, there's a mention of point >>>> objects, which seems to be just for that purpose. However, there's not >>>> too much documentation of the point objects. How do I use them? Do they >>>> offer a lighter overhead than the render spheres? Can I give them >>>> colors? >>>> On the final note, a word about my system: I have a thinkpad >>>> T43, with Pentium M Dothan 1.86MHz, 1GB PC2-4200 memory, ATI X300 mobile >>>> discrete graphics(M22) with 64MB of VRAM, and 60GB 7200rpm disk. It's >>>> not a powerful machine by today's standard, but it runs the old version >>>> of visual just fine. Also, runs other 3D accelerated openGL programs >>>> like googleearth and stellarium just fine(glxgears score, which I know >>>> is not a benchmark, is around 1750 FPS). >>>> The software environment is an outdated ubuntu(5.04), with >>>> custom compiled 2.6.18 kernel, gcc version 3.3.5, python 2.4, fglrx >>>> proprietary driver 8.42.3(latest). Numpy 1.0.3, the latest gtkglxtmm I >>>> compiled and installed from source. If you want to know more, let me >>>> know what more relevant info I can give. >>>> If there's a simple patch for the stable version 3.2.9 that >>>> enables transparency, I'll be very happy to use that, too. Because >>>> really the stable version satisfies all my need except for >>>> transparencies. >>>> Thank you all for any hint/help you can give. >>>> Jiang >>>> >>>> ------------------------------------------------------------------------- >>>> This SF.net email is sponsored by: Splunk Inc. >>>> Still grepping through log files to find problems? Stop. >>>> Now Search log events and configuration files using AJAX and a browser. >>>> Download your FREE copy of Splunk now >> http://get.splunk.com/ >>>> _______________________________________________ >>>> Visualpython-users mailing list >>>> Vis...@li... >>>> https://lists.sourceforge.net/lists/listinfo/visualpython-users >>> ------------------------------------------------------------------------- >>> This SF.net email is sponsored by: Splunk Inc. >>> Still grepping through log files to find problems? Stop. >>> Now Search log events and configuration files using AJAX and a browser. >>> Download your FREE copy of Splunk now >> http://get.splunk.com/ >>> _______________________________________________ >>> Visualpython-users mailing list >>> Vis...@li... >>> https://lists.sourceforge.net/lists/listinfo/visualpython-users |
