Hi all, I'm trying to work out how to modify an existing, out of the box Revit family, a window, to create a new one, and struggling with it.
What I'm looking to do is to take the family (from the metric uk template) "Windows_Sgl_Horz_Bars.rfa" and add a second window bar in. What I'm finding is I can copy the window bar extrusion easily enough, but getting it to constrain to the sides of the window frame as the middle one has been done (position not changed from the original) , it doesn't work, when I flex the model I keep getting "constraints are not satisfied" warnings.
Any suggestions as to what I'm doing wrong?
When I move the copied extrusion to the sides it looks like it is snapping to the constrain line of the pre-existing window pane, I don't understand why the new alignment with an existing one doesn't work.
I had been looking to generate a lot of new family content by modifying what has come out of the box, if I can't fathom it, its going to be a lot of work.
Thanks in advance.
Solved! Go to Solution.
The problem is in the original horizontal bar. The sketch of the extrusion has some constraints assiciated with it which are used to keep the extrusion in the middle of the window when the size is changed. By using a plain copy command to position the 2nd horizontal bar it has problems when the window size is changed.
If you create a 2nd horizontal bar extrusion from scratch (and make all new constraints to keep that one in position too) then it will work. Attached is the example I made. Not sure if it is exactly what you are after.
Thanks for the assist, taking another look I hadn't realised how many constraints there were.
Now I can where I'm going wrong I'll have another crack it it.
Just tried flexing your version, the window frame offset-External doesn't work, wants to delete the constraints and the extrusion added as the second bar?
Not quite sure how these things are supposed to work, the feedback from the Family editor on any problem is pitiful, either freezes up or wants to delete everything.
The frame offest external parameter can be adjust somewhat. I was able to change it up to a value of 240mm in the family editor. I think it has to do with the width of the host wall so the maximum that value can be changed will depend on the thickness of the host. (just guessing)
When attempting to modify an existing family this can be one of the difficulties. it is very hard to know where all of the constraints are located and how they interract with each other. Because of this it is often easier sometimes to create a family from scratch and flex as you add each constraint to make sure the family is responding as expected. With all kind of preexisting constraints and parameters it can be very hard to unravel it all to figure out where the difficulty is. Feedback in the family editor can be difficult because generic error messages are used to identify a very specific problem. In this example we know the parameter it is related to but I have no way of knowing all of the geometry it is connected to and it can literally be connected in an infinate number of ways, so Revit throws a generic error (constraints not satisfied) The issue can be compounded when the constraints are not visible in your current view, or hidden "inside" of a sketch as was the case with the first issue.
If making a family from scratch the typical work flow is to place reference planes you will use to control geometry (skeleton) then place the constraints to control the reference planes (muscle), and then add the geometry aligned to the reference planes (skin). Then flex to test the constraints, and then go through the process again for the next element of geometry. Building a family like this will help reveal constraint errors as you create them and the problems are much easier to resolve.
Not sure what I'm doing then, when I try and change (in the family types editor) the FrameOffset - External dimension from 50mm to a mere 100mm, it doesn't like it?
Rest of your post makes sense, I was hoping for an easy win...looks like if I want a collection of non-out of the box families I'm going to have to spend the time creating them myself.
Having done a LOT more playing around, but with other object types, the solution to this was there all along, from what had been hours of not getting anywhere, its now only taken me 20 minutes to get the right result from creating a double horizontal bar version, and then 10 minutes to create a triple.
Workflow was to take the existing family object, then (instead of copying the centre horizontal bar extrusion) simply editing the profile to create another loop, then lock the edges of the profile as required to things like the glass face. The glass is then similarly changed with the extrusion modified.
Easy to do this once you know what you are looking at....
Thanks for your assist.
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