Face-hosted elements in groups acting all crazy

[patricks]

I have an apartment complex with 3 buildings with lots of identical balcony/porch assemblies, which I have grouped together to make it easier to propagate changes among all the porches. In each balcony group I have a number of face-hosted trim pieces (Hardie-Plank trim). All the face-hosted elements are all hosted to walls WITHIN the same group.

I can create the group and copy the group along the front of one building just fine. The problem comes when I try to place that group on another building, which sits at a different angle. I get errors about the trim losing its host, becoming unhosted, which then makes the group different, so I can either ungroup or make a different group type. Then I end up with a ton of different group types which does me no good at all.

At this point I have resorted to creating different groups for different buildings. It's still a ton of work having to make the same changes in every different group for every different building. Is there a better solution?

[cliff collins]

I think the problem is that the Group was created with a Workplane set at a specific angle in the original bldg. Then when you try to place it on the next bldg which is at a different angle, it errors out because the workplane of that building is different.

If you have a bunch of buildings on the site, in the same model, could you try linking them into a Master Site model--and work on each bldg. in a separate file? That way your Groups would be bldg specific and behave properly.

[david_peterson]

Rotating Groups and Mirroring them causes many, many unexplainable problems.
The other thing I've noticed is that objects that need to be hosted (Face based, Ceiling or Wall) tend to run into problems in the end.
Walls and doors are the worst.
I think in general the way to get groups to work the best is to include everything with them (objects and hosting objects).
Just my 2 cents.
Have you tried saving the group out and importing it that way?

[Duncan Lithgow]

Rotating Groups and Mirroring them causes many, many unexplainable problems.

Agreed! Wow, I hate groups - wish we didn't need them sometimes...

[DaveP]

We've recently redone our entire Casework library for a second time.
First go-round was Wall Hosted. Those wouldn't work with Linked files & at the time we had a lot of Shell and Interior models.
So we redid them as Face-Based instead of Wall-Hosted. That worked better until we started using Groups more.
As Dave says, one of the tricks is to make sure that the "Face" (be it Wall or Reference Plane) is included in the Group.
But Groups still screwed up a lot.
The third re-do was started over from scratch and made them completely non-hosted. Hopefully the 3rd time's the charm.

"But what if the wall moves?", you ask.
There's a little-known parameter in most families called "Moves with nearby elements" that we're training people to use.
Assuming your family has a Strong Reference that is parallel to the Wall it's placed near, with that parameter checked the family will magically move when the wall does.

[patricks]

Rotating Groups and Mirroring them causes many, many unexplainable problems.
The other thing I've noticed is that objects that need to be hosted (Face based, Ceiling or Wall) tend to run into problems in the end.
Walls and doors are the worst.
I think in general the way to get groups to work the best is to include everything with them (objects and hosting objects).
Just my 2 cents.
Have you tried saving the group out and importing it that way?

That's the thing, though, the face-hosted elements in the group are all hosted to a wall which is also included in the group!

It's too late in the game to try to split the buildings out into separate models. Plus, having it that way would be even more cumbersome trying to update the groups in various different projects, as opposed to having a group for each building and updating each of those in the same project.

It's the exact same group in all cases, just at different angles relative to the site. Sure wish a single group would have worked...

This same project has a group for the entire interior construction of the 2-bedroom apartment unit, used in every single building, and so far that group seems to be working fine.