• ### Bezier Curve accomplished

and file attached

It's hacky, but it works.

and it's half-way elegant.

my next step is throwing together a three-point version. will be easy now ive got the idea

http://www.pdpatchrepo.info/hurleur/lxi_bezcurvehack.pd

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• Cool. I know crap all about math. What would you use this for?

• Actually, I'm also out to lunch when it comes to the maths.

I pieced this together after reading a friendly write-up online.

I wanted curves that I could interact with on a visual level. To make waveshapers. I'll also be able to add one or two things and adapt this into a nice, visual soft-clipper.

and the theory behind that is just putting a sexy curve into an array, and then passing signal through tabread4~

The way I threw this together is strange because I'm trying to adapt a parametric equation. so I have curves for both x and y-values, then I plot the x-values into the final plot kind of non-linearly, following the y curve. I had to make the final graph smaller in order to avoid dropping spots in the array.

This version should not drop values as long as the bezier control points are within the bounds of zero to one. I think.

• Lars,

I'd like to use this curves to make a ASR envelope, reading the values from your tables.

Did you developed any other patch with this one as source?

Do you have any suggested bibliography/references to understand the details of how this works ?

Thanks for sharing.
damian.

• yes this is very cool, and i also am lacking in the math to understand this... would you please post a link to the 'friendly article' you read as inspiration for this patch?

cheers!

michael

• Thanks so much for sharing your design. I've been trying to figure out something similar for a project I'm working on. Not really for waveshaping, but to generate exponential ADSR envelopes, similar to the GEN routines in Csound. I think working with a visual representation of waveforms can really help with design.

If you could share the article that inspired you that would be sweet. If you have any new developments with this patch please let me know!!

Thanks!!

• Hi,

did you know my abstraction [jmmmp/bezier]? It does a 4-point cubic bezier
curve, with several other features like parameter export and recall. With
0.43-ext comes the control version, probably in the next edition the
signal version will be there as well. But I send both here.
I also wanted to do a version with unlimited segments, but I didn't find
the math for it yet (it's not the same as calculating one segment after the other using the same formula), and also it's not that trivial to program it with data structures. The best would be if someone would make a real external using a tcl/tk gui, but that might not happen that soon.

João

http://www.pdpatchrepo.info/hurleur/beziers.zip

• Make a bunch of gridded beziers and you could have more draw/visualization/arb-waveform capabilities, very cool!

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