Why won't a masking region in light fixture show in Arch's model?

[patricks]

I work in an architecture office and am working with my electrical engineer to figure out a way to get his 2x4 lay-in fixtures at least appear to cut our ceilings. To do this, the ceiling grid line passing through the center of the fixture needs to be obscured.

We have not found a way to make his light actually cut my ceiling. If that's possible, someone please let me know. But this is a troffer light fixture, so it doesn't have a plastic lens, and we're trying to have it obscure that ceiling grid line without actually having to add a piece of solid geometry in the family below the host plane (these are face-hosted families).

I tried adding a masking region to the plan representation of the light fixture, but it still doesn't obscure the ceiling grid line in my file, even when the view is set to Hidden Line. It doesn't obscure the line in his ceiling plan with my file linked in as an underlay, nor does it obscure the line in my file with his file linked in.

What am I missing? There has to be a way to make this work. Having our ceiling grid line pass through the middle of all these 2x4 fixtures just looks plain sloppy IMHO.

[mwiggins]

Look at the attached families. These should work. There is a mask layered on the reference level. It is set to work in coarse. If I remember correctly it will not mask in the host model but will mask in the link.

[mhartmann]

you as the arch can copy/monitor all the light fixtures (in 2012) from the mep model, then the copy in your model should cut your ceiling. the electrical will have to turn off your arch light fixture category in their linked model (but it's probably already off).
careful now, that will make the ceiling look right, but when they load in your model with the holes in it, all of their light fixtures will have lost their host (because there's no ceiling there to attach to any more). i think this is ultimately worse than the 2x2 grid not being cut.
maybe you could open detached and do this only for major printings and quit out, or do it and print and undo.
hth
mike