// produce animation data
#if 1
	for( int i = 0; i < count; ++i )
	{
		m_positions[ i ] = animSource->m_positions[ i ];
		m_rotations[ i ] = animSource->m_rotations[ i ];
		m_scales[ i ] = animSource->m_scales[ i ];
		m_factors[ i ] = animSource->m_factors[ i ];
	}
	if( count > 0 )
	{
		Vec3 off = m_bonePositions[ 0 ] - posns[ 0 ];
		m_positions[ 0 ] += m_invSkinOffsets[ 0 ].TransformNormal( off );
	}
	Mat4 skinXF[ SGRX_MAX_MESH_BONES ];
	for( int i = 0; i < count; ++i )
	{
		skinXF[ i ] = m_mesh->m_bones[ i ].boneOffset;
		if( i > 0 )
		{
			int pid = GetParentBoneID( i );
			skinXF[ i ] = skinXF[ i ] * skinXF[ pid ];
		}
		
		// gather average global target/local original child pos.
		Vec3 avgtgt = V3(0);
		Vec3 avgpos = V3(0);
		int cc = 0;
		for( int ch = i + 1; ch < count; ++ch )
		{
			if( GetParentBoneID( ch ) != i )
				continue;
			avgtgt += m_bonePositions[ ch ];
			avgpos += posns[ ch ];
			cc++;
		}
		
		if( cc == 0 )
			continue;
		
		avgpos /= cc;
		avgtgt /= cc;
		
		Mat4 curxf = Mat4::CreateSRT( m_scales[ i ], m_rotations[ i ], m_positions[ i ] );
		Mat4 inv = Mat4::Identity;
		( curxf * skinXF[ i ] ).InvertTo( inv );
		avgtgt = inv.TransformPos( avgtgt ).Normalized();
		avgpos = m_invSkinOffsets[ i ].TransformPos( avgpos ).Normalized();
		m_rotations[ i ] = m_rotations[ i ] * Quat::CreateAxisAxis( avgpos, avgtgt );
		
		skinXF[ i ] = Mat4::CreateSRT(
			m_scales[ i ], m_rotations[ i ], m_positions[ i ] ) * skinXF[ i ];
		
		m_factors[ i ] = 1;
	}
#else
	for( int i = 0; i < count; ++i )
	{
		m_positions[ i ] = animSource->m_positions[ i ];
		m_rotations[ i ] = animSource->m_rotations[ i ];
		m_scales[ i ] = animSource->m_scales[ i ];
		m_factors[ i ] = animSource->m_factors[ i ];
		
		int pid = GetParentBoneID( i );
		if( pid >= 0 )
		{
			// rotate bone with axis/angle in bone space
			Vec3 nmdir = m_bonePositions[ i ] - m_bonePositions[ pid ];
			Vec3 omdir = dirs[ i ];
			
			Vec3 tf_nmdir = m_invSkinOffsets[ i ].TransformNormal( nmdir ).Normalized();
			Vec3 tf_omdir = m_invSkinOffsets[ i ].TransformNormal( omdir ).Normalized();
			m_rotations[ i ] = m_rotations[ i ] * Quat::CreateAxisAxis( tf_omdir, tf_nmdir );
			
			// rotate child bones backwards
			for( int ch = i + 1; ch < count; ++ch )
			{
				if( GetParentBoneID( ch ) != i )
					continue;
				tf_nmdir = m_invSkinOffsets[ ch ].TransformNormal( nmdir ).Normalized();
				tf_omdir = m_invSkinOffsets[ ch ].TransformNormal( omdir ).Normalized();
				m_rotations[ ch ] = m_rotations[ ch ] * Quat::CreateAxisAxis( tf_nmdir, tf_omdir );
			}
		}
		else
		{
			// move bone set in world space
			m_positions[ i ] += m_invSkinOffsets[ i ].TransformNormal( m_bonePositions[ i ] - posns[ i ] );
		}
		m_factors[ i ] = 1;
	}
#endif