void CNode::Predict( float fTimeDelta ) // fTimeDelta = time elapsed in seconds since last frame
{	
	....

	// angular estimates.  We need at least 2 items in the list to try this
	if( m_spatialHistoryList.size() > 1 )
	{			
		std::list< spatialHistory_t >::const_iterator i = m_spatialHistoryList.begin();
		
		// get the two most recent orientations as confirmed by the server
		spatialHistory_t shCurr = (*i);
		spatialHistory_t shOlder = (*++i);		
        
		// given two quaternions, q1 and q2, a quaternion representing the difference between each is
		// quatDiff = q1^-1 q2 where q1^-1 is the inverse.  Use conjugate instead since our quats are unit length.
		// Once we have this value, we have the difference for a given time period.
		D3DXQUATERNION rotationDelta, oldInverse;
		D3DXQuaternionConjugate( &oldInverse, &shOlder.sh.orientation );
		D3DXQuaternionMultiply( &rotationDelta, &oldInverse, &shCurr.sh.orientation );
                
		// get the length of time taken to move between these two orientations and convert MS to S
		DWORD dwTimeDeltaBetweenUpdates = shCurr.dwServerTimeStamp - shOlder.dwServerTimeStamp;
		float fSecsBetweenUpdates = (float)dwTimeDeltaBetweenUpdates * 0.001f;

		// We know the rotation difference and the time taken to travel between these two orientations
		// so now we need to work out what the equivalent rotation would be for the period fTimeDelta

// what now?


	}
}

// angular estimates.  We need at least 2 items in the list to try this	if( m_spatialHistoryList.size() > 1 )	{					std::list< spatialHistory_t >::const_iterator i = m_spatialHistoryList.begin();				// get the two most recent orientations as confirmed by the server		spatialHistory_t shCurr = (*i);		spatialHistory_t shOlder = (*++i);		        		// given two quaternions, q1 and q2, a quaternion representing the difference between each is		// quatDiff = q1^-1 q2 where q1^-1 is the inverse.  Use conjugate instead since our quats are unit length.		// Once we have this value, we have the difference for a given time period.		D3DXQUATERNION rotationDelta, oldInverse;		D3DXQuaternionConjugate( &oldInverse, &shOlder.sh.orientation );		D3DXQuaternionMultiply( &rotationDelta, &oldInverse, &shCurr.sh.orientation );                		// get the length of time taken to move between these two orientations and convert MS to S		DWORD dwTimeDeltaBetweenUpdates = shCurr.dwServerTimeStamp - shOlder.dwServerTimeStamp;		float fSecsBetweenUpdates = (float)dwTimeDeltaBetweenUpdates * 0.001f;		// We know the rotation difference and the time taken to travel between these two orientations		// so now we need to work out what the equivalent rotation would be for the period fTimeDelta				// Theory: Get the frame time as a fraction of the delta between the two confirmed updates		// then exponentiate the quaternion rotationDelta by this value like so:		// fExpVal = fTimeDelta / fSecsBetweenUpdates		// quaternion finalAngle = quaternionExponentiate( rotationDelta, fExpVal ) 		float fExpVal = fTimeDelta / fSecsBetweenUpdates;		if( fabs( rotationDelta.w ) < .9999f )		{			float fAlpha = acos( rotationDelta.w );			float fNewAlpha = fAlpha * fExpVal;			rotationDelta.w = cos( fNewAlpha );			float fMult = sin( fNewAlpha ) / sin( fAlpha );			rotationDelta.x *= fMult;			rotationDelta.y *= fMult;			rotationDelta.z *= fMult;		}		D3DXQuaternionMultiply( &m_spatial.orientation, &m_spatial.orientation, &rotationDelta );	}