How can I get G2 fillet from two curve with Dynamo

Furthermore, I am aware of I can get some useful python API by grasshopper from Rhino,or by dynamo from Revit. Does Alias has something like that. I am appreciate if someone can lead the way for me. Thanks very much.

Did you already try the Arc.ByFillet tool? Not sure about the continuity of the result.
Yes, you can use Python in Dynamo. These is a note called “Python Script”.

Thank you for your reply. The result of Arc.ByFillet is G1 curve. I need G2 curvature curve in some A class quality surface. Moreover, I know Python Script . What I want to know is that can I have more control from the API file.

Okay, then I’m afraid there is no G2 fillet at this point in time, sorry.

No, beside Python being available in Dynamo, there is no different access for Python to the API of Alias.

I hope one day, Dynamo can be more convenient than Grasshopper. As far as I can tell, There are a lot of parametric design in automotive industry all use Grasshopper!

With the Dynamo Player in Alias 2021.2 respectively 2021.2.1, there are some good reasons to switch (at least partially) to Dynamo, as you can now create your own tools in Alias. Something, Grasshopper can’t do. :wink:

I know this funvtion, but what I want most is that I can use the alias tools from Dynamo. Futhermore, I think the dynamo UI is horribly. I don’t understand why we have the Point.Bycoordinates(x,y,z) node, then we still have the Point.Bycoordinates(x,y) node. what’s the point of it. That is one example. For instance, Curve.Extend, Curve.ExtendEnd, Curve.ExtendStart. Can we make them only one node. This is just my opinion. I do not know the development history of Dynamo. If I’m wrong, please forgive and correct me.

If the dynamo can do all the work, there is no need to exchange data from different software. That will be wonderful.

I cannot really comment on the Dynamo UI history, I am not part of that team. I do agree that some things there are clunky, but I would hope that this clunkiness goes away over time, with more people using it.

Still, already now you can do powerful things, which I will be evaluating over the next months. :slight_smile:

Hi, GG. I think I understood the questions. For Alias users, we are playing with complex surfaces/structures (for example G2 fillet or draft surfaces with specific draft angles) which can not be done with the existing nodes and Design Scripts elements in Dynamo. But we know clearly how to build in Alias workflow. So if we can use Alias API library in Dynamo Python, we can fix all the issues.

Now the question is: Can we use Alias library in Dynamo Python scripting environment?


Hi Yao,
This is not possible yet, but already logged in our system as improvement ALS-4334.

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Thanks for the reply, GG,
Just want to emphasize again how important it is to have access to Alias libraries in Dynamo. As an Alias and Grasshopper user, I have to say Dynamo is a very promising tool for both car/product designers and 3D modelers, but unfortunately, its ability is still far from enough in actual project scenarios…
Build a better connection between Alias and dynamo could be a practical solution. Just like Revit & Dynamo, Rhino & Dynamo. By the way, Dynamo Player in Alias 2021.2 is already a big step towards the direction we eagerly await.

Very appreciate your work and I have faith in Autodesk products. I believe very soon we car designers can finish all the 3D design tasks In Alias and don’t have to switch back and forth between different softwares.


Thanks for your feedback, Yao, we are aware that this improvement would be huge. :slight_smile:


Hello!! I have a simple solution about two fillet from two curve. I use the node call “By betweenCurves” But fillet have a lot of spans. and I can’t fix this. So I use the other solution. The solution not really G2 fillet. But is approximate.
Sorry, My English is not good . I can’t explain this. You can look my Dynamo capture

Unfortunately, we don’t have access to better fillet functionality from Alias inside of Dynamo yet (this is a known issue).
I am surprised that the result has so many spans. Could you share your Dynamo script here?

It doesn’t work, when the filleted line is not a straight line. In my opinion, if I’m not wrong, you use the curve point as control point.

Grasshopper can get G1 fillet curve, but it can not get G2 fillet curve the same as Dynamo. Still, we can get the similar G2 curve fillet in some way.

OK. This is my file. Create this is not easy by Dynamo. Because create anything always from scratch. Grasshopper doesn’t need.Hexagon_G2_Chord_Fillet.dyn (44.3 KB) Hexagon_G2_Chord_by_hand_Fillet.dyn (74.6 KB)

You’re right. This way only be used straight line. Use curve is not good. Maybe I have to find the curve tangent then create point…

I know grasshopper have the good way create this. and I Hope Dynamo can be better in the future. Because I don’t like file conversion. :joy:

Thanks for sharing the files. I’m pretty busy these days, but I will look into it at the weekend. Will let you know what I find.