Points Lines

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 From:  Frenchy Pilou (PILOU)
4183.1 
Does exist a trick for change the curve A in the curve B except redraw all?

The two curves have same points of references (and it's not corner points)
Seems points can't be jointed to a curve :(

As soon as moving controls points of curve's A, curve goes away of the landmark Points :(

I know that is more Bezier curves' system but is there a trick to mimic it?

Or I miss something :)

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 From:  Michael Gibson
4183.2 In reply to 4183.1 
Hi Pilou, no currently there is not a way to edit a curve like that - you would need to draw a new curve using the Freeform > "Through points" command to make a new curve that is forced to go through those same exact points.

But applying a big change to a curve while at the same time trying to force it through some same specific points will tend to make the curve have wiggles and bulges in it, so that's something to be aware of - each of the "constraints" that you apply to a curve kind of applies pressure on to it and prevents it from having a more fully smooth shape.

In the future there will probably be some kind of history mechanism that will allow you to edit the points of a "through points" curve to update it.

- Michael
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 From:  hairykiwi
4183.3 In reply to 4183.2 
Hi Michael,

Just a quick show of appreciation for when and if such functionality exists in future.

This would be particularly useful for drawing airfoil sections, which are (historically) defined by two lines intersecting given coordinates and a leading edge radius.

Hamish
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 From:  adamio
4183.4 In reply to 4183.3 
Michael not sure if you are familiar with Spiro by Raph Levien ...very interestin :0 http://levien.com/phd/LevienSequinCAD09_014.pdf

I wish we could license his library...
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 From:  adamio
4183.5 In reply to 4183.4 
Oops my apologies, I should have search the forum before I post...I see Levien's work has been mentioned before.
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 From:  BurrMan
4183.6 In reply to 4183.3 
"""""""""""This would be particularly useful for drawing airfoil sections, which are (historically) defined by two lines intersecting given coordinates and a leading edge radius.""""""""""""""

Do you know that Michael added a "Conic curve" command? he also added an RHO value input to it.... FYI.
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 From:  Michael Gibson
4183.7 In reply to 4183.3 
Hi Hamish, yup like Burr says try the Conic command for a traditional airfoil curve.

It's available under Draw curve > More > Conic, and it lets you draw 3 points to make a shoulder bracket of 2 intersecting lines, and then either pick a point for the curve to go through or enter a "rho" value.

Some more information here:
http://moi3d.com/2.0/docs/moi_command_reference2.htm#conic

- Michael
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 From:  Michael Gibson
4183.8 In reply to 4183.4 
Hi adam,

> I wish we could license his library...

Yup, I wish so too, it's pretty cool!

I've tried to contact the author about commercial licensing, and unfortunately it appears that he does not have enough time and/or interest right now to do that.

In the future I want to experiment with some ideas on interpolation with a minimization in curvature changes that may give a kind of similar effect.

- Michael
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