Allow curves/arcs/splines for line-based families

[scbunker]

We should be able to make line-based families do whatever we want. Straight lines are too limiting. This could be accomplished by sketching the path of the line, using whatever drawing tools we want.

My particular application for this is for flexible lighting, but I'm sure it has other applications.

It would still be important for Revit to calculate the total length of the line. This way, for the flex light application, I can calculate the total wattage.

Others, please respond with additional applications so we can get some broader support for this.

[Kevin.Bell]

Agreed - and the curves / arcs should be grip editable intuitively - as happens in AutoCAD.

You can't drag a curves grips in Revit to new locations which are outside the curve... The user has to create a new curve.

[eramoy]

And can they also stay chained when you tab-select like detail lines, please.

[Anonymous]

I agree. I use it to model linear architectural structures to cover ramps (columns+ceiling inside one family). Though I can't do curves and some of the ramps are curved...

[reza_darestani68]

Dear Autodesk Team,

I hope this message finds you well.

I am writing to suggest an enhancement for line-based families in Autodesk software. Currently, these families only support straight lines, which limits design flexibility. It would be highly beneficial if curved lines could also be incorporated within line-based families.

This feature would significantly improve modeling capabilities, allowing for more organic and complex shapes while maintaining the efficiency and parametric control that line-based families provide. Integrating curved line support would enhance workflows for users who require more advanced design elements, particularly in architectural and engineering applications.

We would greatly appreciate your consideration of this request and look forward to any updates regarding this potential feature.

Best regards,
REZA FARAHANI

[Mark_Engwirda]

@reza_darestani68  definitely useful but I don't know if they can make it happen,  but who knows. 

[aizaiwutuobang]

功能强大！虽然可以通过使用框架梁作为替代品来实现，但仍然存在许多限制。

[aizaiwutuobang]

Great function! Although it can be achieved by using framed beams as a substitute, there are still many limitations.

[hj.rozendomSTYFU]

Structural framing families already allow this, so it should be possible for line based families as well.

[maniasadi81]

Current Behavior: Generic Model Line-Based families in Revit can only use a straight line as their driving/host path. Users draw a line, and the family's geometry stretches or scales along that straight reference.

Problem: This limits the family to simple linear geometry. For more sophisticated shapes — such as a form that needs to follow a bent, curved, or arc-based path — there's currently no way to do this within a basic Generic Model Line-Based family. Revit already demonstrates that this is technically feasible elsewhere: railing systems, for example, can follow bent/curved paths and adjust supports accordingly. However, this capability isn't extended to general-purpose Generic Model Line-Based families.

Suggested Improvement: Allow Generic Model Line-Based families to accept curved or arc-based reference lines as their host path, not just straight lines — similar to how railing systems handle bent paths. This would let users create more complex, reusable parametric geometry (like curved hangers, brackets, or custom profiles) without needing to step up to full Adaptive Component families for every curved use case.