Hi Fredrik, I guess it is possible to have a close approximation of a Superellipse as a weighted NURBS curve, I found a reference here:

http://ebrary.free.fr/Mesh%20Generation/Handbook_of_Grid_%20Generation,1999/chap30.pdf

See section: 30.3.5 Superellipse to NURBS Curve


But I believe that this is the first time anybody has asked for a superellipse primitive directly in MoI... I'm not sure about adding that in to the default UI - it is kind of bad for the default UI to get overly clogged up with too many really specialized things in it.

It seems like it could be something to add in as a plugin instead of as a default primitive.


Also have you tried using the Conic command to make a very similar kind of a shape? That will make a hyperbola segment. (EDIT: that will actually be the same as your tests with setting the weight on the middle point so you did end up trying this already).

I'm not quite sure but that chapter above may be trying to fit a hyperbola to the super ellipse as well.

- Michael

Michael

You are right, filling up the interface with special curves is no good idea.
The article does explain how you approximate the super ellipse with NURBS, and it seems like what i did yesterday was pretty close.
Ill look into i when i get home from work.


Thanks for your time.
Best,
Fredrik

Hi Fredrik, so another possible way to make a particular kind of curve is to generate a regular curve made up of many control points, with all the points arranged by the particular formula. That again makes a kind of approximation of the exact curve but with a lot of points it can have only a very small deviation from the exact curve definition.

That sounds like what you were probably doing in Grasshopper already?

If you want to do something similar in MoI, it could be possible to make a plugin that does that kind of a thing - that's actually how the sine wave plugin from this previous post works:
http://moi3d.com/forum/messages.php?webtag=MOI&msg=1519.38

- Michael