smooth "bezier-like" fonction from 7 sliders ?

hey, that looks pretty good to me. a smoothing-styled function would be a nice addition to [function] or as a new object.

You can also use filtergraph~ (with cascade~ to have multiple ones at once), then with the right filter type and other settings, your mousing will get you similar curves. just take the output and use it as you want (there's a query inlet to get the value of any point on the curve).

>>hey, that looks pretty good to me.

No!!! That's not good at all ! look at the handmade drawing below, made from the same exactly sliders values.
This is what i'm looking for.
It is quite different.
The one above really have too much "mountains" compared to this one below...

(p.s: but if you like it, the patch is in attachment)

mmh, thanks for the filtergraph idea but I don't find this solution really practical. (i need the first value to be exactly 0., and the last exactly 1.)

Aren't there anywhere a real "bezier" object or something similar ?

hehe, I like the sketch. Just scan it and use that one! lol

Will take a look at your mxj, sounds interesting. Would like to see how you did the math part.

For bezier-style, maybe something with jit.gl.sketch / strokepoint / jit.gl.nurbs? Wonder if the nurbs object will do the smoothing automatically, seems like it might.

I know this topic has been talked about before, and I think there were some other examples from people on here. Not sure what the results were though.

Again, a real bezier-type object in the standard distribution would be great... or a solid way to make them out of [function] etc. via just the right math.

In fact i realized that my math part (very simple averaging between slopes using a cosine fonction) is just wrong for this application.

>>I know this topic has been talked about before, and I think there were some other
>>examples from people on here. Not sure what the results were though.

me too i remember more or less about a topic like this that i cannot recover. what i remember is that the result wasn't so interesting.

>>Again, a real bezier-type object in the standard distribution would be great...

;-) ++1

>>For bezier-style, maybe something with jit.gl.sketch / strokepoint / jit.gl.nurbs?
>>Wonder if the nurbs object will do the smoothing automatically, seems like it might.

mmh... you're the jitter pro. i found this : http://gritche.perso.libertysurf.fr/OpenGL/Bezier.html
all this gl stuff is really mysterious to me... you think you could manage some simple example using this ?

The a-hspline3d external by André Sier. implements a Hermite spline - guaranteed to pass through the control points and allows adjustment of tension etc. I thought there was a 2d version too but I can't find it..

iirc, there is a bspline object in jasch's lib, too, so you might like to have a look there.

i did some testing of different interpolation methods some time ago.
below is a short example that compares hermite vs. windowed sinc interpolation.
i hope i got the maths right (the hermite code is from musicdsp.org i think), it looks ok though.

sinc-interpolation should be 'smoothest' in theory. to make it work in praxis you need to truncate the infinite function using a window. the size of it and the window function itself have a big influence on the results of the interpolation. for simplicity in the example below i used a von hann window, but if you want to get serious with this method, you should consider something more versatile, e.g. a kaiser window.
volker.

Thanks guys!

a-hspline3d is a very nice object.

Volker, I put your hermite (in your example it was looking better than sinc) algorithm in mxj (mxj is much more manageable to put severals "smooth-func" in a patch), mmh there is still some situations where i feel it be could better*, (see preset n°5), but in general it's not that bad.

I also managed to adjust better my slope-algorithm but hermite is really better.
+ some weird curves options.

patch below.

* i don't know if there is a way to change the "smoothness" of your hermite algorithm by changing the numerical factors ?

The thread is 3 months old, but I thought I would comment...

I wrote an external called sa.function a while back that is like the function object and has multiple lines and bezier curve support. I attached a sample file with the curve you're looking for. It has a lot of features and requires combinations of shift/alit/cmd/ctrl/right-click to manipulate the curves, so make sure to check out the help file.

The attachment only includes a OS X external, so let me know if you're using Windows. It's also only for Max5.

Toshiro,

Great work!!!

-Ben