Transformation Shapes curvature in % - what function is behind that?
- KVRAF
- 1758 posts since 15 Mar, 2013 from Germany
Hi guys,
a general question about transformation shapes in Multiparams. You can grab a line by a point in the middle and drag it up/down to get curvature, and there is a percent value (you see the same also in other plugins, synth ADSR curves, DAWs etc.)
I didn't find info on it in the MXXX documentation. Some info on this would be welcome, maybe even the math behind it (just roughly). So there are a bunch of different curvature modes available (just calles Mode1, Mode2, Mode3 etc), also an "integral curvature" feature, but info is really really short on all this.
Are there certain Modes and/or percent values where the curve is equivalent to a square or exponential function? More info would be nice!
Thanks & Cheers
a general question about transformation shapes in Multiparams. You can grab a line by a point in the middle and drag it up/down to get curvature, and there is a percent value (you see the same also in other plugins, synth ADSR curves, DAWs etc.)
I didn't find info on it in the MXXX documentation. Some info on this would be welcome, maybe even the math behind it (just roughly). So there are a bunch of different curvature modes available (just calles Mode1, Mode2, Mode3 etc), also an "integral curvature" feature, but info is really really short on all this.
Are there certain Modes and/or percent values where the curve is equivalent to a square or exponential function? More info would be nice!
Thanks & Cheers
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- KVRAF
- 10374 posts since 2 Sep, 2003 from Surrey, UK
The graph is the transformation. The input value is the X-axis and the output value is the Y-axis. "Curvature" just controls the shapes of the graph between two points.
For specific functions, try out the Expression Evaluator (in the "Properties of all points" window):
Or you can calculate the co-ordinates (normalized into the range 0..1), save it as a CSV file (change the commas to semi-colons) and Import it.
For specific functions, try out the Expression Evaluator (in the "Properties of all points" window):
Expression evaluator
Expression evaluator lets you generate points based on a mathematics formula. The only input variable is 'x', so as an example you may write 'ln(x^3 + 1) - sin(x*x)'.
Expression evaluator uses traditional C/C++ style formatting, which is natural for most people. It provides arithmetic, logical and conditional operators. Following terms are supported:
Unary operators: - (negative sign), ! (logical negation)
Binary arithmetic operators: +, -, *, /, ^, %, max, min
Binary logical operators: ==, !=, <, <=, >, >=, &&, ||, ^^
Unary functions: log, sqrt, sqr, abs, exp, sin, cos, tan, sinh, cosh, tanh, inv, asin, acos, atan, ln, log10, sgn, floor, ceil, round, rand, f01 (frequency from 20...20000 into log scale 0..1)
Ternary logical operator: a ? b : c (if a is true, then the result is b, otherwise it is c)
Constants: pi, e, sqrt2, ln2

Or you can calculate the co-ordinates (normalized into the range 0..1), save it as a CSV file (change the commas to semi-colons) and Import it.
- KVRAF
- Topic Starter
- 1758 posts since 15 Mar, 2013 from Germany
Thanks, so that is a good way to generate any function curve I want.
It would still be nice to know what functions the predefined curves are (Mode1, Mode2, Mode3, Double1 Double2). When you have just two points and create a curve using the middle point handle.
It would still be nice to know what functions the predefined curves are (Mode1, Mode2, Mode3, Double1 Double2). When you have just two points and create a curve using the middle point handle.
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MeldaProduction MeldaProduction https://www.kvraudio.com/forum/memberlist.php?mode=viewprofile&u=176122
- KVRAF
- 14339 posts since 15 Mar, 2008 from Czech republic
Sorry, no time for showing mathematical functions. To be honest, I don't even understand why. Anyways if I remember correctly, the first is based on ^2, second on ^4 and the third on ^x, where x is based on curvature somehow. The rest of them are more complex.
- KVRAF
- Topic Starter
- 1758 posts since 15 Mar, 2013 from Germany
Thanks. Yeah in the end the ear should decide. It would just be interesting. But I understand there are more important things.
- KVRist
- 428 posts since 23 Jun, 2012
It looks like exponential for me. If you wan't a more sinusal pr pi-ish (don't know) curve (like Vital, Serum, Image Line...), free is the best mode for it. I always use free, because i like the sound more. It's softer in the transitions, exponential is a little to "edgy" for me.
