Drawing better-looking Bézier curves • Hacker News Board

Re: Drawing better-looking Bézier curves

#21

Post by dhotson » Tue, Feb 13, 2018, 2:05 PM UTC

amelius wrote: post #20

dhotson wrote: post #13

Earlier quoted context omitted.

Thanks! Actually it wasn't too difficult. It's all in C++ but the Adobe Illustrator SDK came with some examples that were pretty close to what I wanted already. Once I'd figured out the maths I had a prototype working in about a day. The one thing left that I can't figure out is how to have the curvature comb update live as you drag the Bezier control points. Currently it only updates when you mouse up.

Does it run on multiple platforms, or only OSX?

It should run fine on Windows as well, but I haven't had a chance to test.

Re: Drawing better-looking Bézier curves

#22

Post by wiso » Tue, Feb 13, 2018, 2:27 PM UTC

speps wrote: post #2

Spiro Curves are a nice alternative: http://www.levien.com/spiro/

I have made demo drawing app using libspiro https://www.youtube.com/watch?v=wZK9MPR_UeE very cool library.

Re: Drawing better-looking Bézier curves

#23

Post by jordigh » Tue, Feb 13, 2018, 2:42 PM UTC

xfig has x-splines (cross splines), and I've always wondered why they never got more popular elsewhere. Basically, they have an extra parameter at each endpoint that allows you to smoothly pick between approximation, smooth interpolation, or sharp interpolation, as odd as that may sound:

http://wiki.povray.org/uploaded/5/5e/LeForgeronXSplines-10.1...

Confusingly, there seem to be other splines called "X-splines" that appear to be completely unrelated, where the X seems to refer to the varying degree of the spline instead of just cubic.

Re: Drawing better-looking Bézier curves

#24

Post by Cenk » Tue, Feb 13, 2018, 2:47 PM UTC

I found Yanone’s SpeedPunk (https://yanone.de/software/speedpunk/) super useful in doing this kind of curvature work while designing typefaces.

Re: Drawing better-looking Bézier curves

#25

Post by ghusbands » Tue, Feb 13, 2018, 2:59 PM UTC

Kiro wrote: post #8

Are the sliders working for you?

If you've enabled Strict Site Isolation in your Chrome flags (as mitigation for Spectre), it makes all of these observablehq notebook sliders not work. That's probably what's affecting you.

Re: Drawing better-looking Bézier curves

#26

Post by ghusbands » Tue, Feb 13, 2018, 3:02 PM UTC

Note for Chrome users: If you've enabled Strict Site Isolation in your chrome://flags (as mitigation for Spectre), it makes all of the sliders in these observablehq notebooks not work.

Re: Drawing better-looking Bézier curves

#27

Post by Kiro » Tue, Feb 13, 2018, 3:12 PM UTC

ghusbands wrote: post #25

Kiro wrote: post #8

Are the sliders working for you?

If you've enabled Strict Site Isolation in your Chrome flags (as mitigation for Spectre), it makes all of these observablehq notebook sliders not work. That's probably what's affecting you.

Yeah, that's definitely it. Thank you! Very interesting.

Re: Drawing better-looking Bézier curves

#28

Post by [deleted] » Tue, Feb 13, 2018, 4:00 PM UTC

dhotson wrote: post #11

Hello :) I'm the author of this notebook if you have any questions. I'm also currently working on a plugin for Adobe Illustrator based on this. Screenshot: https://i.imgur.com/tIPTjLsr.png

[deleted]

Re: Drawing better-looking Bézier curves

#29

Post by berendk » Tue, Feb 13, 2018, 4:06 PM UTC

dhotson wrote: post #11

Hello :) I'm the author of this notebook if you have any questions. I'm also currently working on a plugin for Adobe Illustrator based on this. Screenshot: https://i.imgur.com/tIPTjLsr.png

Nice Article!

May I ask how you made the notebook interactive? Is this based on a jupyter notebook?

Re: Drawing better-looking Bézier curves

#30

Post by [deleted] » Tue, Feb 13, 2018, 4:13 PM UTC

dhotson wrote: post #17

amelius wrote: post #14

I'm wondering how well one could define curves by using the physical model of a strip of material, and allowing one to change the properties (stiffness) of the material at different points along the curve, or to insert more material at a given point. Of course, there should be the usual constraints that the strip should pass through a bunch of given (x,y) coordinates, and there could be constraint that "pins" the str…

It's really interesting if you look at how CAD handles this stuff. It lets you set the degree of curvature-continuity/smoothness you want—and it kind of takes care of filling in the curve for you. You have to give up some direct control over the curve if you need it to meet these constraints. Here's what different degrees of curvature continuity look like: http://help.autodesk.com/cloudhelp/2017/ENU/Alias-Tutorials/.…

[deleted]