So I'm getting into the swing of creating some ceiling based families and am finding issues with them. Basically I want to create ceiling-based families that have a plan representation. I know this has been discussed before.
At first I thought something changed drastically in 2009, but I went back to 2008 and the behavior is very similar. The Ref. Level in the family does not adhere to the hosting level in the project. So if I add a model line from the ceiling face (or ref. plane) and lock one end here and the other to the Ref. Level, when the family is inserted in the project and the hosting surface elevation is varied, that model line doesn't flex. It stays the same length as in the family. In 2009, if you lock to the ref. level and the ceiling/ref. plane, it seems that the ref. level becomes the ceiling plane (goes upwards) instead of downwards towards the floor.
So essentially if this behavior doesn't work as one expects, it seems impossible to create a plan representation of a fixture that is overhead, such as a projector. I tried a face-based family, but it doesn't get any better because I can't "flex" the model line vertically (the ref. level in the family will become your workplane surface in the project and has nothing to do with the horizontal level you place your walls on). All I'm trying to do is get a symbolic plan representation if the family is intersected by my project view's cut plane.
If this is true, I might just abandon hosted families altogether and do a regular workplane/level hosted family and specify the equipment vertical offset through an instance parameter. Ugly, but works. Any thoughts/experiences? Thanks!