Formula

[Anthony Miguel]

I'm trying to create a window with mullions. I created a nested family for the mullions with two different mullions to choose from (YES/NO). Up to this point no problem. My problem start when I have three diferent mullions to choose from. In my Family types what formula should I use so that only one of my three mullions are visible in my window family?

[mruehr]

What about using 3 different nested families

[crispin.schurr]

We're pretty new to nesting but we are experimenting at the moment with something similar.
We have frame, leaf and mullion "child" families that will flex into the 5 different systems of aluminium extrusions we use.
Once these are inserted into the assembly family and locked to reference planes, we are applying "family type" parameters to each of the nested families.

By then creating new family types in the assembly family, we can individually select a "35mm residential suite" or "40mm commercial suite" and have the whole door / window geometry flex to the correct profiles, no matter how complex.

I think the biggest thing to look out for are the number and type of reference planes, as Revit tries to find connections between planes that are not there.

Use only 2 reference planes (x and y) as strong references, and make all the others not a reference at the child level to avoid issues. Use the "offset" property of the child at the assembly level to locate on the z axis.

Only problem we have at the moment is nesting our host based wall openings (incl trim / sill tiles etc) - see previous post.

Hope this helps - C