Is there a quark that does PdefPreset-like multi-segment morphing (i.e. Env-like)?

Questions
1

This isn’t too big of a deal to adapt/extend, but PdefPreset (from the JITlib extension quark) only does morphing (and xfading) between a pair of [pre]settings, even though it can store more than two such settings sets.

I was wondering if someone hasn’t already implemented an Env-like present morphing, i.e. a multi-segment PdefPreset “morph”, preferably one that is known to work with Pdef.envir, although one for plain Environments would be useful to to me as well.

2

If I’m understanding what you’re looking for correctly, I think you can do that with this:

It allows you to crossfade between a list of value streams or event streams, using several algorithms for blending values.

(
Pdef(\a, Pbind(
	\octave, 3, \degree, 0,
	\amp, 0.5
));
Pdef(\b, Pbind(
	\octave, 4, \degree, 0,
	\amp, 1
));
Pdef(\c, Pbind(
	\octave, 5, \degree, Pseq([3, 5], inf),
	\legato, 2,
	\amp, 0.1
));

Pdefn(\xfadeEventTest, 
	Pbind(\dur, 1/6) 
	<> Pxfade(
		[
			Pdef(\a),
			Pdef(\b),
			Pdef(\c),
		], 
		Pseg([0, 2], [20]),  // envelope morphing through the three event streams
		\event,
		\randBlend
	).trace
).play;
)

Word of warning - there’s a lot packed into this class, and I’ve used it on exactly one project, so it has seen only limited testing. Enjoy :slight_smile:

2 Likes
3

I see a limitation in Pxfade that it seems to assume “equally spaced” time points; I see there’s Pseg in the standard library (which allows any spacing of the time points), but it doesn’t really do “keyframe interpolation” (as interpolating/morphing between different presets/envirs might be called in a graphics context) but Pseg only interpolates between single numerical values or apparently arrays too. I suppose one can do a envir conversion to/from arrays, but it would be rather annoying.

I see there’s mmPresetInterpolator too

It looks like it has all the bells and whistles one could possibly want… except a notion of interpolating over time :frowning: So yeah, it’s more of a Pxfade alternative.

Fairly off-topic aside: interesting paper on interpolating drum beat patterns, although not done in SC.

4

It doesn’t assume equally spaced points in time - it doesn’t have any notion of time at all, that’s the responsibility of the caller. It simply takes an xfade parameter and interpolates between N event streams based on this parameter (plus a function that tells it how to interpolate). You can drive the xfade parameter with a Pseg if you want interpolation over time - or drive it with a knob, a server bus value, a pattern, etc.

5

That’s a good point. One can turn any interpolator into an Env-style interpolator that way.

I’m having a bit of trouble with Pxfade expecting isSymbol to be defined seemingly for a lot of things. I guess it’s defined in some other quark/extension of yours. It seems to work with the obvious thing for that

+Object {
    isSymbol { ^false }
}

+Symbol {
	isSymbol { ^true }
}

I’m guessing the degreeToKey overrides (e.g. to SimpleNumber) in exScale.sc are so that the interpolation steps are smaller…