topic Re: Constraints not satisfied for angled reference lines in Revit API Forum

Constraints not satisfied for angled reference lines

bpfluid — Wed, 22 Nov 2017 21:56:48 GMT

Hello!

We are trying to create a reference line for hosting MEP connectors (ducts and pipes) that can be positioned and oriented in space using family parameters (lenX / lenY / lenZ and angXY / angZ). We have a solution that works in Revit 2016, but in Revit 2017 we are getting "Constraints not satisfied" errors for certain combinations of parameters. Please advise how we can avoid this error or catch it as we are creating the families and types from code.

Steps to reproduce:

- Open "Angle Test 2D.rfa" in Revit 2017

- Set lenX = 1000.0

- Set lenY = 0.0

- Set angXY = 0.0

- This will result in "Constraint Error.png"

The file "Angle Test 3D.rfa" contains the full, 3D version that also exhibits the same issue. One other thing we have tried was to place all lines on the Ref. Level, which removes the constraint error but totally messes up positioning of the lines; otherwise, the angled line is placed on the plane of one of the other reference lines.

Also note that we can not use nested families, because Revit will not recognize any connectors defined in those for the main family.

Re: Constraints not satisfied for angled reference lines

jeremytammik — Thu, 23 Nov 2017 16:26:27 GMT

Dear Bpfluid,

Thank you for your query.

Are you doing anything programmatically, or just using the standard Revit user interface?

If you are not doing it programmatically, please note that this discussion forum is dedicated to programming Revit using the Revit API.

Therefore, you cannot expect an answer to a question such as yours relating to installation, product usage or end user support issues here.

You should try one of the non-API Revit product support discussion forums instead for that:

https://forums.autodesk.com/t5/revit-api-forum/this-forum-is-for-revit-api-programming-questions-not-for/td-p/5607765

The people there are much better equipped to answer your question than us programming nerds.

If you are doing it programmatically, please be aware that the Revit API hardly ever supports any functionality that is not also available in the user interface.

Therefore, if the UI does not support this, the API will probably not do so either.

I hope this clarifies.

Thank you for your cooperation and understanding.

I searched for the terms Revit and "Constraints not satisfied" and found answers to similar questions in the Revit Architecture and MEP discussion forums:

Maybe these existing threads will already answer your question.

If not, then maybe one of those forums is the best place to raise this.

I hope this helps.

Best regards,

Jeremy

Re: Constraints not satisfied for angled reference lines

bpfluid — Thu, 23 Nov 2017 16:48:32 GMT

Dear Jeremy!

Thank you for your response. While this problem is strictly reproducible from the UI, we are using the API very heavily. In fact, one of the reasons we must do things this way is that there is no API function that we could find that is able to place connectors at the ends of reference lines - or even reference lines on the perpendicular planes of other reference lines. So we have to create this 'harness' in the UI and then copy it from API.

Nevertheless, I will take your advice and cross-post the question.

From the API side, a partial solution would be if we could somehow catch and handle the error from the API (while setting the parameters), that would already improve the situation...

Thanks again!

Re: Constraints not satisfied for angled reference lines

bpfluid — Thu, 30 Nov 2017 11:57:31 GMT

The problem has been solved in the Revit MEP forum, see:

https://forums.autodesk.com/t5/revit-mep-forum/constraints-not-satisfied-for-angled-reference-lines/m-p/7570155