We have created lighting fixtures to our office standards and are having problems with trimming out ceiling grid lines when placing them in the RCP. First things first, Upon making our electrical central fille.......we link our (in-house) architecural file, using orign-to-origin, therefore being able to host our light fixtures to the ceiling grids of our linked arch model. When doing this on a 2'x2' ACT ceiling the fixture snaps to the ceilings but does not trim out the ceiling grid within the fixture. We even tried to edit the family and lower the extrusion a couple inches below the reference plain (ceiling grid). Anybody else having issues like this.
We just had a problem like this. We found that sence the Arch background is referenced into the project then anything that trys to host to a ceiling grid will not work properly bc the Arch background contains the RCP and that is not editable in the workset.. it is a reference only. We did a test of re-creating a job with the Arch background as part of the workset and then tried to host to the RCP and it worked perfectly.. it also cut the lights into the ceiling.The only work-around was placing the lights "on face" and having the architect cut in the lights. (we did not like this and it's a long work around) But what can you do..
I hope this helps you in some way!