We have a section where it spawns a fake wall. After all, it is my wife's creation and it is a temple, so you never know what "traps" will appear.
She had a spot with an invisible wall, but you can't get past it. You can see the two pillars standing at the archway. You have to find another way to enter the room and as you round a corner, she had a rumble sound and triggered the pillars to make it look like they collapsed. So it was an "illusion" yes.
The pillars are small square at the bottom base, but long and round for the columns so I see where you are going. We found another idea with the smaller boulder to work so all is good once again in the land of BlackFox and his wife
Thanks you guys.