Nested Linear Generic Model Family

[mcobb]

I have run into this issue with nested linear generic model families a few times and it seems like something worth resolving. The potential efficiencies seem promising. I often will want to use an extrusion in multiple locations in a generic model family. Using a nested linear generic model family seems like a promising place to start. I make the linear generic model family first with the appropriate profile. Then I nest this linear generic model family in the host generic model family, hoping to lock this linear family to the appropriate intersections of reference lines in the host family. This appear to work with reference lines, but I can't get it to work between the more orthogonal geometry composed of reference planes. Any thoughts on what I am doing wrong? I can certainly just make extrusions that replace my linear generic model family but this seems less efficient that simply using this linear generic model family everywhere (if I can get it work). Any help is greatly appreciated. I'm attaching the start of my family here as well.  I am specifically having problems getting the vertically oriented linear generic model family to snap to the "top" reference line and the Ref. Level without breaking a constraint.

[barthbradley]

Is this what you are after?

Note "A" and "L" Parameters.  

edit: revision attached. Missed an "L" on the first one. 

[mcobb]

I'm afraid not. I would like the vertical "Garden Window Mullion" Family to simply flex with the adjustment of height so I can use this linear family everywhere. But I am starting to suspect I should simply create a profile and use that in multiple applications (extrudes and sweeps).  Thank you for trying to help, the angle geometry is not really what I am struggling with at present.

[barthbradley · Accepted solution]

I don't understand what you are after then. All I know is the family you posted was breaking to smithereens when I tried flexing it using your parameters. This is what I corrected for. Note that the nested family's "Length" parameter and associated Ref. Plane has been deactivated and replaced with an "L" Parameter and Ref. Plane which controls the geometry's Length.   Maybe this is information that will help you.  

[martijn_pater]

The parameter to flex it should be an instance parameter, in a line-based gen family this is the default (length), and lock it to your family refplanes... or you need to create a dimension with reporting parameter and associate it to the type/instance of your nested family...

FWIW btw for any family step 1: create your refplanes and parameters, flex those to see if it works, then add the geometry...

[mcobb]

Hi BB.

Yes, it was breaking to smithereens. Well said. :). I was in the middle of making some modifications but wanted to at least share something that featured the vertical element. I should have prepped the family more before posting it.

I think the central point you are making, that is quite useful, is that linear generic families are of less utility than I might imagine. It is better to simply use a generic model family that has a length parameter. They seem to behave better. For what I was doing, I was hoping to streamline my workflow with a kind of universal use of linear families to make a kind of spaceframe structure. I've seen this kind of behavior with adaptive families but I don't think it applies particularly well here.  I was probably crossing the line from efficient, to lazy in my approach.

I will upload the family when it is done for your review. If you have the time and it isn't an imposition, I would really appreciate your thoughts on how efficiently or inefficiently it was made.

[barthbradley]

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@mcobb wrote:

I will upload the family when it is done for your review. If you have the time and it isn't an imposition, I would really appreciate your thoughts on how efficiently or inefficiently it was made.

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Be happy to.   

[martijn_pater]

aw, I really ought to upgrade to rvt2021 it seems ^^, would help you but I'm afraid I can't open your file atm...

[ToanDN · Accepted solution]

In principle, it is better to nest non-line based families into a line based family.

The main benefit of a line based family is that you can draw it in project as a chain of line on the fly without worrying about changing parameter or stretching the grips after placement. What you do, while it can work, is negating that benefit entirely.

[mcobb]

This is a bit more like what I was hoping to accomplish ("Garden Window 3"). It basically had a bunch of angles with miters meeting at corners. It turned out to not really be worth the trouble to have a bunch of nested families, even after I switched from linear to standard generic model templates (See Generic Window 3"). Turns out Revit just couldn't handle all those families meeting in one corner. Kinda similar to what happens with too many walls meeting in one corner. In the final analysis, I think it is more of a sweeping problem. Simple is good. Still have to place the glass...

Any thoughts on better workflow are always welcome and thanks for talking me down from my crazy linear family idea.

Mike

[mcobb]

Very insightful. Once again, thank you for taking the time.

[barthbradley]

Not sure what kind of feedback you are looking for here.

Window 3 has no Nested Linear Generic Model Families in it -- which I thought was the aim -- and Window 2 has Nested Linear Generic Model Families in it, but breaks and throws errors when flexed.   It's definitely fixable though.  Are you interested? 

[mcobb]

Hi BB-

You are right, there was something up with the horizontal mullions on the roof. It should be fixed now. I think I've done enough with this one. I really appreciate your comments. Thanks again. The final version (or at least as "final" as I need it to be) is attached to this.

Regards,

Mike

[barthbradley]

Nice job.