Creating passible objects

Hi,

So been trying to recreate something that for life of me cants seems to do.

So I made a bed that you can walk through sims will just walk to the markers on the bed to get in, sit whatever.

I originally made this when i was just experimenting around with simsstudio, but now that i've found a great use for this effect cant seem to replicate it.

So anyone know how to make sims walk through a object as if it was air, but it still functions?

I do have the original creation and I know i was messing around with the bones of the object, but recreating it just seems to crash have no effect or just simply not spawn.

I'd apprieate any help as its driving me up the walls. Please and thank you!