Re: [simspark-devel] ODEImps Plugin

[Joschka B. <jos...@am...>]

Hey Hedayat,

On Feb 22, 2010, at 4:39 PM, Hedayat Vatankhah wrote:

> Hi Andreas!
> 
> On ۱۰/۰۲/۲۲  10:49, ah...@un... wrote:
>> Hi,
>> 
>> 
>> I am now one step closer to having the ODE classes as a plugin. I use the
>> PhysicsServer for testing for now, because this is a class that is
>> actually used, as opposed to the AngularMotor, and thus obviously more
>> suited for testing. PhysicsServerImp now shows up in the scenegraph; the
>> key was to build odeimps not as a library, but as a module (which is the
>> desired method anyway, as building it as a library was merely a
>> workaround).
>> 
>> I changed spark.rb a bit so that it imports the odeimps bundle at the very
>> beginning. The relevant part now looks like this:
>> 
>> ----- begin excerpt from spark.rb -----
>> #
>> # setup spark
>> #
>> 
>> print "(spark.rb) setup\n"
>> 
>> #import the implementations of the desired physics engine
>> #currently supported: odeimps (uses Open Dynamics Engine)
>> importBundle "odeimps"
>> print "(spark.rb) using ODE, to change the physics engine go to line 559
>> in spark.rb\n"
>> 
>> #
>> # set up logging
>> logServer = get($serverPath+'log')
>> 
>> if (logServer != nil)
>>   logServer.addStream(':cerr', 'eError')
>> end
>> 
>> 
>> #
>> # setup the PhysicsServer
>> sparkGetPhysicsServer()
>> ----- end excerpt from spark.rb -----
>> 
>> Here's a screenshot of rsgedit which proves that the odeimps bundle gets
>> imported correctly, and also showcases that the PhysicsServerImp shows up
>> at "/classes/PhysicsServerImp":
>> 
>> http://www.uni-koblenz.de/~aheld/rsgeditscreen.png
>> 
>> Since I can now be 100% sure that PhysicsServerImp is now registered at
>> /classes/PhysicsServerImp _before_ the PhysicsServer is set up [as
>> importbundle"odeimps" is called prior to sparkGetPhysicsServer()], I can
>> now instanciate mPhysicsServerImp in the PhysicsServer's OnLink method
>> like this:
>> 
>> void PhysicsServer::OnLink(){
>>     mPhysicsServerImp = shared_dynamic_cast<PhysicsServerInt>
>>         (GetCore()->New("/classes/PhysicsServerImp"));
>> }
>> 
>> This leads to the following console output:
>> 
>> ----- begin inexplicable console output ----
>> (ScriptServer) Script ended OK /home/andreas/.simspark/kerosin.rb
>> (ScriptServer) Running /usr/local/share/simspark//spark.rb...
>> (spark.rb) setup
>> (spark.rb) using ODE, to change the physics engine go to line 558 in spark.rb
>> (Core::New) unkown class '/classes/PhysicsServerImp'
>> (GeometryServer) MeshImporter 'oxygen/StdMeshImporter' registered
>> ----- end inexplicable console output -----
>> 
>> As even a trained monkey could see, the odeimps bundle is imported, and
>> thus PhysicsServerImp registered at /classes/PhysicsServerImp immediately
>> before Zeitgeist complains that PhysicsServerImp is not registered at
>> /classes/PhysicsServerImp. The RSGEdit screenshot proves that
>> PhysicsServerImp is registered at /classes/PhysicsServerImp.
>> 
>> Soemhow the PhysicsServer is set up before PhysicsServerImp is registered
>> even though spark.rb registers PhysicsServerImp before the PhysicsServer
>> is set up. This is a time paradoxon. Maybe I'm using a quantum computer
>> without knowing it?
>> 
>> Any ideas would be appreciated.
>> 
> IMHO, you should simply use
> 
> GetCore()->New("PhysicsServerImp")
> 
> Instead of
> 
> GetCore()->New("/classes/PhysicsServerImp")
> 
> And it should work fine!

That's it, thanks a bunch! :-)

Cheers,
Joschka