Curve point's 'strength'

Please see the attached photo - as an example, I'm making a curve through 4 points. I'm wondering if there's any way to assign a 'strength' to each point, for example a slider, where if the value is 0 the point has not impact of the curve, and where the value is 1, the curve forms a sharp corner at that point.

Does anyone have any ideas?

Thanks

James

Replies to This Discussion

Permalink Reply by Michael Pryor on May 7, 2013 at 3:43pm

change the curve degree.

Permalink Reply by Michael Pryor on May 7, 2013 at 4:10pm

try this.

Permalink Reply by Jesus Galvez on May 7, 2013 at 4:16pm

This is a practical solution, maybe it won't work for you.

Try first averaging the points to get the barycenter. Then plotting lines from the barycenter to each point. Then evaluate the lines and finally do what Michael said with the evaluated lines points.

You might have to fine tune it so that it doesn't change the start and end positions of the curve and to obtain points that are above the lines domain.

Permalink Reply by Danny Boyes on May 7, 2013 at 4:20pm

There is a Nurbs Curve component that allows you to specify weights. You will need to manually input Knot Vectors but there is a default component available as well.

Permalink Reply by Jesus Galvez on May 7, 2013 at 4:29pm

I don't understand what [Knot Vector] does. I input the length of the point list (4) and get:

0.0

1.0

Could you clarify a bit Danny? Thanks!

Permalink Reply by Danny Boyes on May 7, 2013 at 4:33pm

Have a look at this

http://www.grasshopper3d.com/forum/topics/grasshopper-070053-availa...

Permalink Reply by Danny Boyes on May 7, 2013 at 4:52pm

I don't believe you tried the Nurbs Curve component

Permalink Reply by Danny Boyes on May 7, 2013 at 5:00pm

It's incredibly bad practice to "stack" control points. the maths involved goes crazy. I highly recommend you do not include the "exact" same point. You will need to move it ever so slightly

Permalink Reply by Fred Becquelin on May 7, 2013 at 5:09pm

the maths involved goes crazy.

Could you explain? I hardly ever experienced issues doing this :/

Permalink Reply by Danny Boyes on May 7, 2013 at 5:15pm

Have you ever used Maxsurf?

They regularly do this sort of thing to create knuckles. But when you try and use the IGES files that have been created this way in other software (analytic) where you are dynamically meshing the hull for CFD or sectioning it for Hydrostatics You get zero length segments. Even Rhino sometimes has issues trying to create a render mesh for display.

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