I am currently using a quake 3 map as my irrlicht scene (the same quake 3 map used in the quake3 map and collision irrlicht tutorials). I also added some bill board scene nodes to represent navigation path nodes.
A strange thing happens such that even if the camera is right in front of a wall or pillar, the bill board scene nodes which are behind the pillar can still be seen even though the pillar is supposed to block them from view.
The same goes for the floor. Even though I set the bill board scene nodes to be way below the quake3 map, they can still be seen through the floor.
How do I ensure that the floor and the pillars/walls block the bill board scene nodes from view?