how to keep snaping a curve (with flex parameter) on a 3D point from family

[heichan88]

Hello, there are 3 ref points from a family (green dots), then I need to snap a curver through these 3 ref points, but when I change parameter, the curve lost its snap.

PS  (1) in the family, the ref line through these green point is set to strong ref. but not work

(2) if make curve on a hosted solid, it can be snapped with flex, but in my case there is no solid because it has been cut..

Thanks

 

 

[barthbradley]

You need additional points (hosted to other points) with their Offsets driven by trigonometric  formulas.  

https://www.revitforum.org/node/1126

[barthbradley]

Hey @heichan88! I didn't see that it was you asking. I would figure that you, of all people, would be one that could solve this.  Maybe I'm misreading the situation.  Post your file.  

[ToanDN]

Change what parameter?  

[heichan88]

hello @ToanDN 

change parameter of span of joist, 

just now I make model line on 3D snapping in the family, then in the host I lock a reference line on that, so now snapped with flex.

Any better solution please advice

Thanks