Help on why my FamilyInstance does not place on points in Dynamo


I am trying to make a Dynamo script that takes two selected points from a sheet and turns them into a line. Then takes that line and divides it into points. Then places a selected family instance at each of those points.

For some reason the family does not place on the points even though when I watch each node it seems to be outputting what I want. But on my screen it is just a blue line with dots of where a device should have been placed.

I need to use a reference plane for the family type devices to place on so that is something I cannot change.

Any help on why this is happening is greatly appreciated. I have attached a screenshot of my current script as well. I am very new to dynamo so I apologize if I used the wrong terminology anywhere.

What is the output you’re getting? Is it placing any instances or none at all? You should probably clean up your list structure to remove the extra list levels you have with the points and the reference. Also, are you sure you’re providing the right kind of reference?

Im just getting null for my output. Yes I believe the reference is correct since when I just connect just one of the “Select Point on Face” nodes straight to the location part of the “FamilyInstance.ByReference” The instance places fine.

I am just confused why it does not place the instances when its a list of points. Any idea on how to fix that?

It could still be the list structure. Right now your reference is a list of a single reference (reduce it to just the single item) and your location points are a list of a list (flatten them to just a single list).

Thank you, flattening the location points list allowed them to place. But the placed instances are still connected by the blue line with blue dots. Do you know why this is? The placed instances also disappear if I try and create a new line. Like I want to be able to make multiple lines of the instances placed if that makes sense.

The blue line and dots are simply dynamo geometry and are not permanent. And re mutiple instances of this might be element binding. Try syncing after 1 run, and then re run the graph to confirm this.

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Thank you, if i run the script and then save and reopen it again then I can place mulitple lines.

This is the intended behavior. Rerunning a graph typically equates to replacing whatever happened in the previous run unless you specifically written for element binding. A new “session” of your graph or running it in Player will create new elements each time.

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Thanks for all your help!