void renderJoints(JOINT* joint, float*data, float scale) {	
	glPushMatrix();

	// translate
	if ( joint->parent == NULL ) { // is Root
		glTranslatef( data[0] * scale, data[1] * scale, data[2] * scale );
	} else {
		glTranslatef( joint->offset.x*scale, joint->offset.y*scale, joint->offset.z*scale );
	}

	// rotate
	for ( uint i=0; i<joint->channels.size(); i++ ) {
		CHANNEL *channel = joint->channels[i];
		if ( channel->type == X_ROTATION )
			glRotatef( data[channel->index], 1.0f, 0.0f, 0.0f );
		else if ( channel->type == Y_ROTATION )
			glRotatef( data[channel->index], 0.0f, 1.0f, 0.0f );
		else if ( channel->type == Z_ROTATION )
			glRotatef( data[channel->index], 0.0f, 0.0f, 1.0f );
	}

	// end site
	if ( joint->children.size() == 0 ) {
		renderSphere(joint->offset.x*scale, joint->offset.y*scale, joint->offset.z*scale,0.07);
	}
	if ( joint->children.size() == 1 ) {
		JOINT *  child = joint->children[ 0 ];
		renderSphere(child->offset.x*scale, child->offset.y*scale, child->offset.z*scale,0.07);
	}
	if ( joint->children.size() > 1 ) {
		float  center[ 3 ] = { 0.0f, 0.0f, 0.0f };
		for ( uint i=0; i<joint->children.size(); i++ )
		{
			JOINT *  child = joint->children[i];
			center[0] += child->offset.x;
			center[1] += child->offset.y;
			center[2] += child->offset.z;
		}
		center[0] /= joint->children.size() + 1;
		center[1] /= joint->children.size() + 1;
		center[2] /= joint->children.size() + 1;

		renderSphere(center[0]*scale, center[1]*scale, center[2]*scale,0.07);

		for ( uint i=0; i<joint->children.size(); i++ )
		{
			JOINT *  child = joint->children[i];
			renderSphere(child->offset.x*scale, child->offset.y*scale, child->offset.z*scale,0.07);
		}
	}

	// recursively render all joints
	for ( uint i=0; i<joint->children.size(); i++ )
	{
		renderJointsGL( joint->children[i], data, scale );
	}
	glPopMatrix();
}