In the editor there should be an option for the designer to select different backwards facing 3D surfaces removal for a material (so called face culling). Usual options for face culling are:

• None, all 3D surfaces are drawn regardless of their facing direction from the camera.
• Back facing (usually the default option), 3D surfaces facing away from the camera are not drawn.
• Front facing, 3D surfaces facing towards the camera are not drawn.

As an example glass balls don't look right without the culling options.