First steps with OgreODE tutorial problem

Hi to everyone. I am completely new to ogre and i am trying to run the example for OgreODE found here: http://www.ogre3d.org/wiki/index.php/First_steps_with_OgreODE

when it runs, it throws an exception:
OGRE EXCEPTION(2:InvalidParametersException): Object already attached to a sceneNode or a Bone in SceneNode::attachObject at ... (a .cpp file in a directory that doesn' exist in my pc)

i was running the tutorial step by step and the exception occured when i added the line
mNode->attachObject(mBody);
after creating a body for the crate.
Can anybody help?? What is the problem?

I have exactly the same problem with this tutorial. Can someone please tell me what am I doing wrong?

Did you try the simplescenes demo? Does it work? Do you use the sdk or the cvs version? I think the sdk has been updated recently but anyway i recommend the cvs version to be sure.

I have tried simplescenes demo, it compiles without any errors (both CVS and SDK version).

I use only two files for the OgreOde tutorial:

The .cpp one is


#include "exampleapplication.h"

class TutorialApplication : public ExampleApplication
{
protected:
public:
TutorialApplication()
{
}

~TutorialApplication()
{
}
protected:
virtual void createCamera(void)
{

// create the camera
mCamera = mSceneMgr->createCamera("PlayerCam");

// set its position, direction
mCamera->setPosition(Vector3(0,10,500));
mCamera->lookAt(Vector3(0,0,0));

mCamera->setNearClipDistance(5);
}

virtual void createViewports(void)
{
// Create one viewport, entire window
Viewport* vp = mWindow->addViewport(mCamera);

vp->setBackgroundColour(ColourValue(1,0,0));

// Alter the camera aspect ratio to match the viewport
mCamera->setAspectRatio(Real(vp->getActualWidth()) / Real(vp->getActualHeight()));
}
void createScene(void)
{
mWorld = new OgreOde::World(mSceneMgr);
mWorld->setGravity(Ogre::Vector3(0,-9.80665,0));
mWorld->setCFM(10e-5);
mWorld->setERP(0.8);
mWorld->setAutoSleep(true);
mWorld->setAutoSleepAverageSamplesCount(10);
mWorld->setContactCorrectionVelocity(1.0);
mSpace = mWorld->getDefaultSpace();

const Ogre::Real _time_step = 0.5;
const Ogre::Real time_scale = Ogre::Real(1.7);
const Ogre::Real max_frame_time = Ogre::Real(1.0 / 4);
mStepper = new OgreOde::StepHandler(mWorld, OgreOde::StepHandler::QuickStep,_time_step, max_frame_time,time_scale);

mGround = new OgreOde::InfinitePlaneGeometry(Plane(Ogre::Vector3(0,1,0),0), mWorld, mWorld->getDefaultSpace());
// Use a load of meshes to represent the floor
int i = 0;
StaticGeometry* s;
s = mSceneMgr->createStaticGeometry("StaticFloor");
s->setRegionDimensions(Ogre::Vector3(160.0, 100.0, 160.0));
// Set the region origin so the center is at 0 world
s->setOrigin(Ogre::Vector3::ZERO);
for (Real z = -80.0;z <= 80.0;z += 20.0)
{
for (Real x = -80.0;x <= 80.0;x += 20.0)
{
String name = String("Ground") + StringConverter::toString(i++);
Entity* entity = mSceneMgr->createEntity(name, "WoodPallet.mesh");
entity->setQueryFlags (1<<4);
entity->setUserObject(mGround);
entity->setCastShadows(false);
s->addEntity(entity, Ogre::Vector3(x,0,z));
}
}
s->build();

mEntity = mSceneMgr->createEntity("crate","cube.mesh");
mEntity->setQueryFlags (1<<2);
mNode = mSceneMgr->getRootSceneNode()->createChildSceneNode("crate");
mNode->attachObject(mEntity);
mEntity->setNormaliseNormals(true);
mEntity->setCastShadows(true);

mBody = new OgreOde::Body(mWorld);
mNode->attachObject(mBody);
Vector3 size(10.0,10.0,10.0);
OgreOde::BoxMass mMass(0.5,size);
mMass.setDensity(5.0,size);
mGeom = (OgreOde::Geometry*)new OgreOde::BoxGeometry(size, mWorld, mSpace);
mNode->setScale(size.x * 0.1,size.y * 0.1,size.z * 0.1);
mBody->setMass(mMass);
mGeom->setBody(mBody);
mEntity->setUserObject(mGeom);
mBody->setOrientation(Quaternion(Radian(5.0),Ogre::Vector3(0,0,0)));
mBody->setPosition(Vector3(0,120,-20));

Entity *ent;
Light *light;

mSceneMgr->setAmbientLight(ColourValue(0, 0, 1));
mSceneMgr->setShadowTechnique(SHADOWTYPE_STENCIL_ADDITIVE);

Plane plane(Vector3::UNIT_Y, 0);
MeshManager::getSingleton().createPlane("ground",ResourceGroupManager::DEFAULT_RESOURCE_GROUP_NAME, plane,1500,1500,20,20,true,1,5,5,Vector3::UNIT_Z);

ent = mSceneMgr->createEntity("GroundEntity", "ground");
mSceneMgr->getRootSceneNode()->createChildSceneNode()->attachObject(ent);
ent->setMaterialName("Examples/Rockwall");
ent->setCastShadows(true);

light = mSceneMgr->createLight("Light1");
light->setType(Light::LT_POINT);
light->setPosition(Vector3(0, 150, 250));
light->setDiffuseColour(1.0, 0.0, 0.0);
light->setSpecularColour(1.0, 0.0, 0.0);

light = mSceneMgr->createLight("Light3");
light->setType(Light::LT_DIRECTIONAL);
light->setDiffuseColour(ColourValue(.25, .25, 0));
light->setSpecularColour(ColourValue(.25, .25, 0));
light->setDirection(Vector3( 0, -1, 1 ));

light = mSceneMgr->createLight("Light2");
light->setType(Light::LT_SPOTLIGHT);
light->setDiffuseColour(0, 0, 1.0);
light->setSpecularColour(0, 0, 1.0);


}
};

#if OGRE_PLATFORM == OGRE_PLATFORM_WIN32
#define WIN32_LEAN_AND_MEAN
#include "windows.h"

INT WINAPI WinMain( HINSTANCE hInst, HINSTANCE, LPSTR strCmdLine, INT )
#else
int main(int argc, char **argv)
#endif
{
// Create application object
TutorialApplication app;

try {
app.go();
} catch( Exception& e ) {
#if OGRE_PLATFORM == OGRE_PLATFORM_WIN32
MessageBoxA( NULL, e.getFullDescription().c_str(), "An exception has occurred!", MB_OK | MB_ICONERROR | MB_TASKMODAL);
#else
fprintf(stderr, "An exception has occurred: %s\n",
e.getFullDescription().c_str());
#endif
}

return 0;
}


And the exampleapplication.h is the following:


/*
-----------------------------------------------------------------------------
This source file is part of OGRE
(Object-oriented Graphics Rendering Engine)
For the latest info, see http://www.ogre3d.org/

Copyright (c) 2000-2006 Torus Knot Software Ltd
Also see acknowledgements in Readme.html

You may use this sample code for anything you like, it is not covered by the
LGPL like the rest of the engine.
-----------------------------------------------------------------------------
*/
/*
-----------------------------------------------------------------------------
Filename: ExampleApplication.h
Description: Base class for all the OGRE examples
-----------------------------------------------------------------------------
*/

#ifndef __ExampleApplication_H__
#define __ExampleApplication_H__

#include "Ogre.h"
#include "OgreConfigFile.h"
#include "ExampleFrameListener.h"
#include "OgreOde_Core.h"
#include "OgreOde_Prefab.h"
#include "OgreOde_Loader.h"

#if OGRE_PLATFORM == OGRE_PLATFORM_APPLE
#include <CoreFoundation/CoreFoundation.h>

// This function will locate the path to our application on OS X,
// unlike windows you can not rely on the curent working directory
// for locating your configuration files and resources.
std::string macBundlePath()
{
char path[1024];
CFBundleRef mainBundle = CFBundleGetMainBundle();
assert(mainBundle);

CFURLRef mainBundleURL = CFBundleCopyBundleURL(mainBundle);
assert(mainBundleURL);

CFStringRef cfStringRef = CFURLCopyFileSystemPath( mainBundleURL, kCFURLPOSIXPathStyle);
assert(cfStringRef);

CFStringGetCString(cfStringRef, path, 1024, kCFStringEncodingASCII);

CFRelease(mainBundleURL);
CFRelease(cfStringRef);

return std::string(path);
}
#endif

using namespace Ogre;

/** Base class which manages the standard startup of an Ogre application.
Designed to be subclassed for specific examples if required.
*/
class ExampleApplication
{
public:
/// Standard constructor
ExampleApplication()
{
mFrameListener = 0;
mRoot = 0;
// Provide a nice cross platform solution for locating the configuration files
// On windows files are searched for in the current working directory, on OS X however
// you must provide the full path, the helper function macBundlePath does this for us.
#if OGRE_PLATFORM == OGRE_PLATFORM_APPLE
mResourcePath = macBundlePath() + "/Contents/Resources/";
#else
mResourcePath = "";
#endif
}
/// Standard destructor
virtual ~ExampleApplication()
{
if (mFrameListener)
delete mFrameListener;
if (mRoot)
delete mRoot;
}

/// Start the example
virtual void go(void)
{
if (!setup())
return;

mRoot->startRendering();

// clean up
destroyScene();
}

protected:
Root *mRoot;
Camera* mCamera;
SceneManager* mSceneMgr;
ExampleFrameListener* mFrameListener;
RenderWindow* mWindow;
Ogre::String mResourcePath;
OgreOde::World *mWorld;
OgreOde::Space *mSpace;
OgreOde::StepHandler *mStepper;
OgreOde::InfinitePlaneGeometry *mGround;
OgreOde::Body *mBody;
OgreOde::Geometry *mGeom;
OgreOde::BoxMass *mMass;
Ogre::SceneNode *mNode;
Ogre::Entity *mEntity;

// These internal methods package up the stages in the startup process
/** Sets up the application - returns false if the user chooses to abandon configuration. */
virtual bool setup(void)
{

String pluginsPath;
// only use plugins.cfg if not static
#ifndef OGRE_STATIC_LIB
pluginsPath = mResourcePath + "plugins.cfg";
#endif

mRoot = new Root(pluginsPath,
mResourcePath + "ogre.cfg", mResourcePath + "Ogre.log");

setupResources();

bool carryOn = configure();
if (!carryOn) return false;

chooseSceneManager();
createCamera();
createViewports();

// Set default mipmap level (NB some APIs ignore this)
TextureManager::getSingleton().setDefaultNumMipmaps(5);

// Create any resource listeners (for loading screens)
createResourceListener();
// Load resources
loadResources();

// Create the scene
createScene();

createFrameListener();

return true;

}
/** Configures the application - returns false if the user chooses to abandon configuration. */
virtual bool configure(void)
{
// Show the configuration dialog and initialise the system
// You can skip this and use root.restoreConfig() to load configuration
// settings if you were sure there are valid ones saved in ogre.cfg
if(mRoot->showConfigDialog())
{
// If returned true, user clicked OK so initialise
// Here we choose to let the system create a default rendering window by passing 'true'
mWindow = mRoot->initialise(true);
return true;
}
else
{
return false;
}
}

virtual void chooseSceneManager(void)
{
// Create the SceneManager, in this case a generic one
mSceneMgr = mRoot->createSceneManager(ST_GENERIC, "ExampleSMInstance");
}
virtual void createCamera(void)
{
// Create the camera
mCamera = mSceneMgr->createCamera("PlayerCam");

// Position it at 500 in Z direction
mCamera->setPosition(Vector3(0,0,500));
// Look back along -Z
mCamera->lookAt(Vector3(0,0,-300));
mCamera->setNearClipDistance(5);

}
virtual void createFrameListener(void)
{
mFrameListener= new ExampleFrameListener(mWindow, mCamera);
mFrameListener->showDebugOverlay(true);
mRoot->addFrameListener(mFrameListener);
}

virtual void createScene(void) = 0; // pure virtual - this has to be overridden

virtual void destroyScene(void){} // Optional to override this

virtual void createViewports(void)
{
// Create one viewport, entire window
Viewport* vp = mWindow->addViewport(mCamera);
vp->setBackgroundColour(ColourValue(0,0,0));

// Alter the camera aspect ratio to match the viewport
mCamera->setAspectRatio(
Real(vp->getActualWidth()) / Real(vp->getActualHeight()));
}

/// Method which will define the source of resources (other than current folder)
virtual void setupResources(void)
{
// Load resource paths from config file
ConfigFile cf;
cf.load(mResourcePath + "resources.cfg");

// Go through all sections & settings in the file
ConfigFile::SectionIterator seci = cf.getSectionIterator();

String secName, typeName, archName;
while (seci.hasMoreElements())
{
secName = seci.peekNextKey();
ConfigFile::SettingsMultiMap *settings = seci.getNext();
ConfigFile::SettingsMultiMap::iterator i;
for (i = settings->begin(); i != settings->end(); ++i)
{
typeName = i->first;
archName = i->second;
#if OGRE_PLATFORM == OGRE_PLATFORM_APPLE
// OS X does not set the working directory relative to the app,
// In order to make things portable on OS X we need to provide
// the loading with it's own bundle path location
ResourceGroupManager::getSingleton().addResourceLocation(
String(macBundlePath() + "/" + archName), typeName, secName);
#else
ResourceGroupManager::getSingleton().addResourceLocation(
archName, typeName, secName);
#endif
}
}
}

/// Optional override method where you can create resource listeners (e.g. for loading screens)
virtual void createResourceListener(void)
{

}

/// Optional override method where you can perform resource group loading
/// Must at least do ResourceGroupManager::getSingleton().initialiseAllResourceGroups();
virtual void loadResources(void)
{
// Initialise, parse scripts etc
ResourceGroupManager::getSingleton().initialiseAllResourceGroups();

}



};


#endif


Is there a particular problem with the above code?

try


mBody = new OgreOde::Body(mWorld);
Vector3 size(10.0,10.0,10.0);
OgreOde::BoxMass mMass(0.5,size);
mMass.setDensity(5.0,size);
mGeom = (OgreOde::Geometry*)new OgreOde::BoxGeometry(size, mWorld, mSpace);
mBody->setMass(mMass);
mGeom->setBody(mBody);
mNode->attachObject(mBody);
mNode->setScale(size.x * 0.1,size.y * 0.1,size.z * 0.1);


I am quite sure that you may not attach a body that has no geometry yet.