render the wheels of the ForkLiftDemo

btgui/Bullet3AppSupport/Bullet2RigidBodyDemo.cpp

@@ -30,6 +30,12 @@ struct MyGraphicsPhysicsBridge : public GraphicsPhysicsBridge
 		:m_glApp(glApp), m_debugDraw(0), m_curColor(0)
 	{
 	}
+
+	virtual struct CommonRenderInterface* getRenderInterface()
+	{
+		return m_glApp->m_renderer;
+	}
+
 	virtual void createRigidBodyGraphicsObject(btRigidBody* body, const btVector3& color)
 	{
 	    createCollisionObjectGraphicsObject(body,color);