Tween curves

[kostgard]

Hi,

In Rhino there is a very useful command called "tween" that creates one, or a user-defined number, of curves between two reference curves(see attached screenshot, 5 tweened curves between two yellow reference curves). Is there a way to replicate this in Revit? Thanks!

[lucdoucet_msdl]

@kostgard 

I will assume you have 3d curves you would like to "tween" between. You could try to create a lofted surface between the two, then assign subdivide the surface with a UV grid of 1 x N where N=the number of steps you want.

Difficult to answer without know the context of what you want to do next with the "tweened" geometry.

Hope this helps,

-luc

[kostgard]

Hi,@lucdoucet_msdl , thank you for your answer! Actually, I'm hoping to do it in sketch mode. I simply need a way to find a centerline between two curves to use as the setting out ceiling panels. Hopefully my sketch below can show it:The black lines indicates the irregular edge curves of the soffit. The red dashed line would be the "tweened" line, that is a centreline that is always equidistant from the two black edge lines. The blue lines are where the panels of the soffit would be split, which we intend to always make 1000mm wide, measured based on the red line(basically, find the centre line, split it into 1000mm long segments, then add the blue lines based on these segments). Hope that is reasonably understandable...

[RDAOU]

@kostgard 

No there is no such tool in Revit...

1. You can use Dynamo to create and remap a set of curves between two curves then set it to run in Dynamo Player 
2. Alternatively, there is something similar which can be done in Alias (if you are wondering that is another Autodesk product)

Should you be interested you could also read the following post 

https://thebuildingcoder.typepad.com/generating-a-midcurve-between-two-curve-elements.html

[lucdoucet_msdl]

@kostgard 

Tried the solution I proposed and it doesn't work as the UV grid is not deformed to follow the curves.

I agree with @RDAOU that this is a good problem for Dynamo and Jeremy Tamiks blog post has some code you can copy into a custom Dynamo node that seems to do exactly what you are asking (ie "tween" a curve equally between two curves).

Another possibility, in that you need a mid curve would be to setup an adaptive shape that divides each edge of the curves to a number of panels and connects theses points with a reference line. You can then generate a "tween" line in the shape that you can snap to with an adaptive model for the ceiling panels. This modelling approach would essentially reproduce what a Python script/Dynamo solution would calculate. The advantage would be not having to run a Dynamo script if the base geometry evolves during the design stage.

The disadvantage of the modelling approach is it may not work between a continuous curve and a polycurve composed of line segments (as shown in your initial sketch). Is this a requirement for your case?

-luc

[kostgard]

Hi, me and my company are very new to Revit. I would like to explore using the script mentioned, but I have 0 experience of Dynamo. Is there are guide with very simple words and plenty of pictures for a total rookie to learn how to implement such a script without actually knowing how its been set up? I have tried googling but to be honest, I don't even know which terms I should search for, and results are all fairly advanced knowledge. As in, there is a downloadable .cs file, how is that loaded into Dynamo? Thank you...

[ToanDN · Accepted solution]

An attempt at doing it manually.  

[RDAOU]

@kostgard 

If you have no knowledge in dynamo what so ever, I would recommend the following:

• Do the Tween Curves in Rhino and bring into Revit as a DWG export/import then use the pick line tool or using RhinoInside Plugin - Download HERE. Fairly quick and much easier for you or who ever does it at your firm

• On the long term look into learning dynamo (the concept is not much different to grasshopper) There are some tutorials on Dynamobim.org. You do not need to fully master it but definitely need the basics to use and/or amend graphs which are available out there

Both ways you would be saving lots of time and money on pointless doodling in Revit. 

[kostgard]

@RDAOU 

Hi RDAOU, I suspected Rhino would come into play. Do you know if there is a quick method to export only the curves I need from Revit, and then get the new curves in the exact same position back in Revit again after tweaking? I would have thought I could have found that for sure on google but no joy. Our company does not have Rhino 7 currently. Thanks!

[kostgard]

Thanks for taking the time. This will be the backup solution if I cannot work out a smooth way to go back and forth to Rhino.

[RDAOU]

@kostgard 

Is there a way? Yes, and I believe you have all the necessary info in the above/previous replies...the rest is up to you to explore.

If you do not manage, you still have  have Toan's solution : o) otherwise you can always hire an expert on Autodesk Marketplace >>> https://servicesmarketplace.autodesk.com/