I am working on a game, and how we did the healthbars for each player in the world was a simple GUI.Box as follows:

 GUI.Box(new Rect(targetPos.x -30, Screen.height - targetPos.y - 46, 60, 20), curHealth   "/"   maxHealth);

The problem is we are using a vision system that utilizes camera tricks and a 3rd party lighting engine to hide enemies out of vision. This works perfectly, but because it hides based on layer and because GUI.Box draws to the GUILayer, the health bars are not being hidden along with the players. I essentially need to draw the healthbars on the hidden layer, so that they can be hidden when not within the vision cone.

I was wondering if anyone knows of any 3rd party library that behaves the same as GUI.Box for drawing a simple box?