How to change the coords of bullet from ogre

g6785654 · Post by **g6785654** » Thu Dec 27, 2012 6:15 am

I use ogre for the 3D engine,use the bullet for the physics engine,connecting both of them I use this code

class MyMotionState : public btMotionState
{
public:
   MyMotionState(const btTransform &initialpos,Ogre::SceneNode *node);
   ~MyMotionState();
   void setNode(Ogre::SceneNode* node);
   virtual void getWorldTransform(btTransform& worldTrans )const;
   virtual void setWorldTransform(const btTransform& worldTrans);
   void updateTransform(btTransform& newpos);

protected:
   Ogre::SceneNode* mVisibleobj;
   btTransform mPos1;
};

MyMotionState::MyMotionState(const btTransform &initialpos,Ogre::SceneNode *node)
{
   mVisibleobj = node;
   mPos1 = initialpos;
}

MyMotionState::~MyMotionState()
{

}

void MyMotionState::setNode(Ogre::SceneNode* node)
{
   mVisibleobj = node;
}
void MyMotionState::updateTransform(btTransform& newpos)
{
   mPos1 = newpos;
}
void MyMotionState::getWorldTransform(btTransform& worldTrans )const
{
   worldTrans = mPos1;
}

void MyMotionState::setWorldTransform(const btTransform& worldTrans)
{
   if(NULL == mVisibleobj)return;
   btQuaternion rot = worldTrans.getRotation();
   mVisibleobj->setOrientation(rot.w(),rot.x(),rot.y(),rot.z());
   btVector3 pos = worldTrans.getOrigin();
   mVisibleobj->setPosition(pos.x(),pos.y(),pos.z());
}

At the main function,I use them like this

Code: Select all

void BulletToOgre(btRigidBody* body,btTransform &trans,MyMotionState* motionstate)      
   {
      body->getMotionState()->getWorldTransform(trans);
      mymotionstate->setWorldTransform(trans);
      body->getMotionState()->setWorldTransform(trans);
   }

   void OgreToBullet(SceneNode* node,btRigidBody* body,btTransform& trans)      
   {
      Vector3 position = node->_getDerivedPosition();
      Quaternion quat = node->_getDerivedOrientation();
      trans.setIdentity();
      trans.setOrigin(btVector3(position.x,position.y,position.z));
      trans.setRotation(btQuaternion(quat.x,quat.y,quat.z,quat.w));
      body->setWorldTransform(trans);
   }

'BulletToOgre' can change the ogre's position and Rotation with bullet,'OgreToBullet' can change the bullet's position and Rotation with ogre.
But now there have some questions,when I want to change bullet's coords with ogre, such as I use mouse to move a model,call OgreToBullet function,onlt a time will success,when I want to move again,the model will appear the lastest position(The position of the success),I try to replace the code of 'body->setWorldTransform(trans);' with ''body->getMotionState()->setWorldTransform(trans);' ,their have different result, I don't if the code I writed wrong,Can someone help me have a look.Thanks!