1.) Enter a military building at an airfield (only tested at Northeast)
2.) Look out the window and get the shards of glass in the window between you and the fence that is across the airfield.
3.) The section of the fence that the glass obscures should become invisible when looked at through the glass.

Have not tried this on other graphical settings, will test and report back.

The screenshot is VERY vague, and I apologize, but you should be able to see that where there should be a fence-post there is nothing. Instead it becomes completely invisibly when looked at through the glass.