Grimrock

...add the glass wall props along a wall, then remove squares behind where you placed one or any of them.They display identically to the regular prop but may be walked through freely as an illusory wall. Perfect! I replaced "dungeon_wall_text" with "temple_glass_wall_1" in the a...

Before I read these posts, I tried a different tactic that has some side-effects I kind of like. I cloned "dungeon_wall_text", set the model to "dungeon_wall_01", dropped it into a wall, rotated it over an opening, and got a nice looking illusionary wall that light can shine thro...