[Physik Engine] Status

[Setsuka]

So what about the physics

During the last few weeks I was busy with another project:
"solving the block stacking problem with an evolutionary algorithm".
I was responsible for holding the presentation about the paper on the conference EA-2007 in Tours. we achieved to get the award for ' the best students paper'. YAY!

Now that is finished and I can finally take care of my beloved physics.

For now we will take ODE as engine. If somebody has something more suitable, tell me...
On wikipedia it is written that it was used for S.T.A.L.K.E.R, which would mean that it is pretty powerful.

The only tutorial I found until now was broken.

The most important function for you at this stage might be the collision detection, so if an 'intelligent' interface is provided, the engine can be still replaced later.

So long Setsuka

[beni]

Heard from other students and PH. D. students who read your paper. They were quite amazed by your work and in my opinion one of the really cool solutions is the Tetris thing you made to ensure that no blocks overlap when you change their x-position.

Anyways, I've only heard good things about ODE and old Orxonox also came close to an ODE implementation. For Ogre there is a wrapper. Check out this page in the Ogre wiki for a starting point.
The wrapper is in the Ogre repository and can be downloaded via CVS.
I don't think we can provide an intelligent interface, but I don't think you should think about changing the engine in the future. Although it would be cool to make it really modular. But let's forget this for the moment.

[x3n]

Hi mathias,

Congratulations on your success with the project paper
I hope you can start soon with the physics support now. I think ODE suits our needs very well.
You shouldnt think about an 'intelligent' interface, as that's too much. Just try to fit ODE into Ogre and Orxonox. The ODE wrapper linked by beni, should be a good start.

[Setsuka]

I'm still fighting with some stupid basics ...

The code version I have atm seems to be outdated. After running the shellscript configure stops with error Ogre 1.2.x not found, something like that which would be an old version

In the forum the link "the latest SDK": "newest version HERE" is sending you to the seemingly outdated version.
They are discussing there that the SDK version is way too old and people should use the CVS version (what is that and where can I get it)

One guy posted a pre-compiled version of ODE and OgreODE, but I didn't try it yet. Thats my next try.

PS: For those who are interested in getting an idea what can be done
here's a demo (18MB)

[beni]

Ogre has a CVS repository like we have a SVN repository. You can find it on http://ogre.cvs.sourceforge.net/ogre/ there in ogreaddons you have all the plugins and stuff. One is ogreode where there is everything you need I guess.

Like I said CVS is very similar to SVN, it's something like an earlier version. In this paper you find everything you need to checkout code from a CVS repository.

Hope I was able to help.

[Setsuka]

Thx for the information.
Yeah, now that you told me it reminds me of the fact, that I once read about that cvs thing ^^

PS : I was far away to be at the end of my nerves

[Setsuka]

Ok, now im really at the end of my nerves...

- Generating the make file is not working, because ogre is not where odeogre is looking for it (yes we tried for 4h relinking and so on ... no success). Maybe isg can solve the problem ...
checking it out on nico's laptop generating make file is working ...

- But then compiling gives errors, at least something

Seems as if after the forum it is quite a patchwork ...

So now I'm frustrated and angry ... now I have to play some shooter ...

[patrick]

Setsuka: the ISG prooved to be very helpful in all our installation/makefile problems. I'm sure they will be able to help you.

Good luck!

[Setsuka]

After that 'GAU' yesterday I also looked for more information and alternatives.

- OgreODE is was last maintained on the 12th of january but not further developed. That explains why the last existing release was based on ogre 1.2.x Dagon and not on 1.4.x Eihort.
Interesting that compiling on nico's laptop it spat out some typecast errors, which would mean me having to debug something I didn't write myself ...

- another choice could be newton game dynamics. Seems like there exists some kind of wrapper.

Side mark: When I checked http://gpwiki.org/ for engines, there is an OGE, open game engine, with pretty similar specs as what we use Ogre , ODE , OAL etc. for, so our choices may not be that bad and I'm really curious about the result.

[Setsuka]

Because on tardis systems it is quite pain in the ass to get something to work (request to ISG, try, doesn't work, run to ISG, still not working...), I now installed linux on my laptop.

Minor achivements
- ode compiles and installs (but in /usr/local/include , /usr/local/lib).
- Created soft links in /usr/include , /usr/lib.
- Adding in orxonoxx.cc #include <ode/ode> seems also to work.

Upcoming
- nico is now trying to add a 'search' for ode so that linking shouldn't be needed.
- Testing accessibility of ode
- Trying to add OgreOde

[Setsuka]

Good morning everybody

Was working again to try make ogre ode working.

Two new disadvantages appeared besides the support:
- There exist no real tutorials:

Tutorial never been done, just planned.

- There exists no documentation:

First of all, ODE's API is way far from being complete or up-to-date.
Secondly, if it makes you embarassed, why don't you do something for the scene? Both OgreOde and Ode have been left non maintained for some time. As for ODE, then things have changed recently, new version was realeased, but there is still no proper docs or anything. OgreOde is doing kinda well too, but any update/doc/general help is welcome. Unhappy with docs? Use Bullet or Newton or something!

few doc is the biggest chink of OGREODE, though it is a good engine and easy to use, expect that a complete API doc or detailed remark of code will be made for our OGREODE fans, we have been used to OGREODE, why do we change?

Exactly, there's no need to. But perhaps, if you are experienced already, you can contribute more towards, say wiki? It is an open thing, so anyone is welcome to join!

Now there are 3 options :
- Try to make ogre ode work and find a way to find out what it can do and write our own wiki
- Use pure ode
- Get other engine

Besides: Until now I don't even know if I can make ogre ode work.

[beni]

Well, I don't know if we can decide for you in this case.

Fact is, that neither ODE nor OgreODE are documented well. I know what a pain it is to read through undocumented code, but in the end it's up to you.
A cool wrapper is a nice thing, but not necessary. If you want to change to another engine do it, but be aware, that it's already end of November.

[Setsuka]

I know that time is ticking...
It would be better to have something well working and also documented
than just something that compiles but nobody knows how to use it...

It's no use to rush something now and in the end somebody has to fix it.

PS : And you know ... if I didn't do enough to get the points .. :p

[Setsuka]

PS About what you mentioned about the dev version:
I installed dev version... I don't find the so called ExampleApplications.

[beni]

I guess the dev only installs you the .h files you need. The ExampleApplication.h file will most certainly only be in the package when you download the SDK or the source.
Those .h files aren't used in the current Orxonox, but you'll need them for most samples.
I'll look what's the content of the package and report back. You may want to search for Ogre.h and such and then copy the example .h files into this directory. You'll get them with downloading the source.