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Re: [Pyode-user] Pyode binary distribution
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From: <al...@ci...> - 2010-03-28 17:32:41
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Hello, It's not enough to add geoms = []. Every time you create a new geom, you do: geoms.append(geom) In my Python 2.5, the ragdoll from your original code was falling through the floor. I guess the difference was in older versions of PyODE: they might not call dGeomDestroy() in the geom destructor, or the body object might have had some references to the geoms. Alex > Thanks Alex. > > Yes the code you have sent is working fine. For some strange reason, when I > added geoms = [] on my original program, ragdoll continued falling. I will > check what is going on. And of course my question would be, why and how was > it working in Python2.5? What is the difference? > > Yes, the ragdoll is from monsterden.net. I think the original one is from > Cornel.edu, bu tI can not remember the exact link now, and I am not sure if > it is the same guy. Well, it is upto you to add it in the examples. It is an > interesting one, and a bit more advanced than falling boxes. > > Kadir > > 2010/3/28 <al...@ci...> > >> Hello, >> >> I found the problem, see the attached file. >> >> Somewhere in the code, there is a line: >> >> # create a list to store any ODE bodies which are not part of the ragdoll >> (this >> >> # is needed to avoid Python garbage collecting these bodies) >> >> bodies = [] >> >> >> A similar code snippet is needed for geoms, too. That's why I added the >> following: >> geoms = [] >> >> >> And after creating every geom, I have added it to that list. That solved >> the >> problem. >> >> "bodies" and "geoms" are not used anywhere in the code. They just say to >> Python's garbage collector: I'm using these objects, do not delete them. >> >> When there are no more references to a body or a geom, PyODE removes those >> objects >> from ODE simulation automatically. That happened into your code: bodies >> were still >> present in simulation (that's why the doll was falling), but all the geoms >> (floors and capsules) were deleted. >> >> Is the ragdoll example the one from >> http://monsterden.net/software/ragdoll-pyode-tutorial ? >> I think it would be nice to include it in the PyODE examples folder. >> >> Alex >> >> > Hello Alex, >> > >> > Thanks for your note and recommendations. I have answed them one by one, >> > next to your questions: >> > >> > Kadir >> > >> > 2010/3/27 <al...@ci...> >> > >> >> Hello, >> >> >> >> First thing you should check: >> >> Do the examples from C:\Python26\pyode-examples run correctly? >> >> >> >> >>> Tutorial 1 runs OK, with the same numerical output >> >>>> Tutorial 2 runs OK with same double pendulum swinging >> >>>> Tutorial 3 runs with the same problem I had with new installation of >> > PyODE. Boxes falling down, penetrating the floor (plane). >> > >> > >> >> tutorial3.py has an example with a GeomPlane some falling boxes and >> >> spheres. >> >> Does it run correctly? >> >> >> > >> >>>> Tutorial 3 runs with the same problem I had with new installation of >> > PyODE. Boxes falling down, penetrating the floor (plane). >> > >> > >> >> I have just tested it with a fresh install of Python 2.6, PyOpenGL 3.0.1 >> >> and >> >> PyODE-snapshot-2010-03-22.win32-py2.6.exe. >> >> It worked from the first try. >> >> >> >> Which version of ODE do you use on Python 2.5? It seems that different >> ODE >> >> versions behave slightly differently >> >> with the same scene description. >> >> >> >> >>>> I believe PyODE 1.2.0, which was installed using >> > PyODE-1.2.0.win32-py2.5.exe. >> > >> > >> >> Do you use PyODE directly from your program or do you have some higher >> >> level >> >> library, like cgkit? >> >> In the second case, please check that it uses the same stepping method >> >> (step or >> >> quickStep) in both Py25 and 26. >> >> >> >> >>>> I use it directly. I use Vpython for visualisation. >> > >> > >> >> Can you send me a small test program, with the floor and one body, which >> >> works >> >> in Py25 and not in 26? >> >> >> > >> >>>>> I am attaching one famous RagDoll I have been using with PyODE. It is >> > supposed to fall and lie down on the floor. >> > Although I know nothing about robotics, I am trying to get this RagDoll >> up >> > and walking. >> > >> > I have visited your robot site. I have downloaded the windows version of >> > your robot and ran it on my laptop. I liked it very much. I tried to >> > implement a similar kinematic robot arm earlier, I had some coordination >> > problems, then I was planning to migrate it to ODE as a dynamic arm. I >> use >> > VPython for visualization, not OpenGL since VPython is very easy to use. >> > >> >> >> >> I am also using PyODE in a simulation which involves bodies sitting, and >> >> sometimes falling, on the ground. >> >> When the gravity, body mass or vertical speed were too high, they could >> >> break >> >> the floor and fall down. >> >> So you may start debugging with reducing the gravity value. >> >> >> >> >>> I set g = -0.81, same behaviour, slow-motion. >> > >> > It looks like a collision detection problem but where? Any double >> Precision >> > / SÝngle Precision issue? >> > >> > >> >> However, the simulation runs exactly the same in Py25 and 26, with >> exactly >> >> the >> >> same code. I do not use >> >> PyODE directly, but all the rendering and simulation is done using >> cgkit. >> >> I'm >> >> using boxes and trimeshes, >> >> and sometimes spheres for debugging. >> >> >> >> The program in which I use PyODE is a robot arm simulator, still in >> early >> >> stages >> >> of development, available here: >> >> http://github.com/alexdu/robot-sandbox . For now, it only runs on >> Windows >> >> out of >> >> the box (unzip and run). >> >> >> >> > Hi again, >> >> > >> >> > I have installed Python 2.6.4 and tried to install PyODE on top. I >> have >> >> > downloaded the >> >> > PyODE-snapshot-2010-03-22.win32-py2.6.exe< >> >> >> http://sourceforge.net/projects/pyode/files/pyode/snapshot-2010-03-22/PyODE-snapshot-2010-03-22.win32-py2.6.exe/download >> >> >from >> >> > the sourceforge and somehow got it working :)) >> >> > >> >> > But now funny things are happening. It looks like the GeomPlane is not >> >> > functioning correctly, so that everything falls down forever. My >> "floor" >> >> has >> >> > gone. The same exact code works OK in Python25, in 2.6, the rest seems >> OK >> >> > for the moment (At least gravity is there, joints are working, bodies >> are >> >> > working OK), but the floor is gone!? >> >> > >> >> > Is it a collision detection problem, although for the remaining parts >> it >> >> > seems to work ok. Bodies are mostly CappedCylinders (plus some >> spheres). >> >> > >> >> >>From Idle, I can see ode.GeomPlane is in there, but somehow it is not >> >> > working OK. >> >> > >> >> > I will check with some other programs, or simple geometries. >> >> > >> >> > Thnaks for your work and support. >> >> > >> >> > Kadir >> >> > >> >> > 2010/3/23 Ethan Glasser-Camp <gl...@cs...> >> >> > >> >> >> al...@ci... wrote: >> >> >> > I have tried to create a binary Win32 installer for latest PyODE >> >> >> snapshot. >> >> >> > I am sure Kadir and others will find it useful. >> >> >> >> >> >> This is awesome, thanks! >> >> >> >> >> >> I have uploaded this, as well as tarballs taken from today's git, to >> the >> >> >> files section of the sourceforge project: >> >> >> >> >> >> https://sourceforge.net/projects/pyode/files/ >> >> >> >> >> >> I've elected to use a snapshot-ymd system, since at present the >> project >> >> >> doesn't have "features" that are added in any regular fashion. >> >> >> >> >> >> I also updated the project website with the git URL and links to the >> >> >> most current files. >> >> >> >> >> >> > Since I'm a beginner in creating Python packages, I have two small >> >> >> issues: >> >> >> > >> >> >> > 1. The installer copies "ode.dll" to c:\python25. Is this a >> problem? >> >> >> > I believe it should be copied into "site-packages" instead, but I >> did >> >> not >> >> >> know >> >> >> > how to >> >> >> > specify this in setup.py. >> >> >> >> >> >> No idea here, sorry.. >> >> >> >> >> >> > 2. The examples are copied into c:\python25\pyode-examples. Is >> there a >> >> >> better >> >> >> > choice? >> >> >> >> >> >> I wouldn't include them at all, frankly. >> >> >> >> >> >> > 3. When installing the binary package to a fresh Python directory, >> >> >> tutorials 1 >> >> >> > and 3 >> >> >> > work fine; the others need pygame and maybe cgkit. Is there a way >> to >> >> >> specify >> >> >> > these dependencies in the binary installer? >> >> >> >> >> >> I think it's fine to leave these out -- not all people who use ODE >> are >> >> >> going to want to use it with Pygame. >> >> >> >> >> >> > I have added examples and ode.dll as "data_files" in setup.py. I >> would >> >> >> also like to >> >> >> > see the setup.py which created the releases from >> >> >> pyode.sourceforge.net(1.2.0). >> >> >> >> >> >> I would guess that the setup.py in the source tree is the one they >> used, >> >> >> but I have no idea. >> >> >> >> >> >> Ethan >> >> >> >> >> >> >> >> >> >> >> >> ------------------------------------------------------------------------------ >> >> >> Download Intel® Parallel Studio Eval >> >> >> Try the new software tools for yourself. Speed compiling, find bugs >> >> >> proactively, and fine-tune applications for parallel performance. >> >> >> See why Intel Parallel Studio got high marks during beta. >> >> >> http://p.sf.net/sfu/intel-sw-dev >> >> >> _______________________________________________ >> >> >> Pyode-user mailing list >> >> >> Pyo...@li... >> >> >> https://lists.sourceforge.net/lists/listinfo/pyode-user >> >> >> >> >> > >> >> >> >> >> > >> > |