Graphics Programs Reference
In-Depth Information
they can't be placed on hosts that exist in any of the linked Revit models. In
other words, you can't place any object-based diffusers on the architectural
ceilingunlessyouhaveceilingobjectsmodeledinyourownMEPmodel(not
through the link).
To make the right decision about what hosting behavior you should choose,
you need to know the pros and cons of those behaviors.
Generic (nonhosted) families behave pretty much like any other object in
Revit—they change location only if you move them.
Object-based families behave like face-based families for the most part,
except that they need the host to exist in the model and not be part of a
linked Revit file.
Face-hosted families have one major advantage: they follow the plane of
the host. Anytime the architect adjusts the ceiling location, your diffusers
will adjust accordingly. Cool, right? Ceiling diffusers follow the elevation
of the ceiling, and the water closet follows the plane of the wall (not the
elevation, but the actual plane of the wall finish). Ironically, this advantage
isitsbiggestdisadvantage.Itisimportanttounderstandthatasyourobjects
movewiththehostedelement,anyconnectedpipesorductswilladjusttofit
and can potentially disconnect and break the integrity of the system. When
you receive the new architectural background and try to open your MEP
model, you will get the message shown in
Figure 19.1
.
Figure 19.1
Message that appears when you're using face-hosted families
This message, as you can see, has only two options: Delete Element(s) will
delete some pipes, pipe fittings, ducts, and duct fittings; Cancel will cancel
the process of opening your project. The bottom line is that in order to open
your project, you must delete certain elements. It is good practice when you
are designing with Revit MEP to have all pipes and ducts connected, and
as you move a main piece of pipe, any branches that exist should extend
or shorten. Knowing that fundamental behavior of Revit, let's translate it
