FR: Make random values (more) repeatable

[IXIX]

Hi Calle,

Random values are fun but it's often desirable to have a "random" part remain the same on every playback. Would it be possible to add a seed value for the random value generators? I'd suggest that if the seed is zero then the values would be truly random but for a non-zero seed, the values would be determined by the seed value and critically, the host playback position.

A global or program level seed would be an improvement but if the seed could be a group or split level parameter that would be better, as it would allow a greater degree of control.

In an ideal world it would be preferable to be able to set a separate seed value for every random value generator but I'm not sure if that would be possible without adding a lot of UI clutter.

Thanks for reading this. Now I'll just wait for you to tell me that this already exists. I checked the manual first, honest!

[IXIX]

Actually, testing with a wave matrix on random and looping the part in REAPER, it seems that the values aren't truly random but repeat a sequence. However the values don't appear to be tied to the play position, so each time I start playback from the top, the output is different.

[elcallio]

No, the random is in fact a noise function, which is somewhat different from true random behavior. I think to achieve what you want you might try using a step lfo with randomized values set to tempo sync. That way you have a pattern controlled by song position. Plus you can edit it to find what you want.

[IXIX]

I think to achieve what you want you might try using a step lfo with randomized values set to tempo sync. That way you have a pattern controlled by song position. Plus you can edit it to find what you want.

That's a good idea but I'm struggling to make it work. I haven't used the step sequencer much so maybe I just don't get it but I can't seem to get it to play back the same sequence of samples on each playback.

For a test, I'm feeding 1/4 notes into a matrix with 8 samples arranged along the y axis, modulated by SEQ1. The seq is set to 8 steps, 1/4 rate, continuous, tempo sync, with stepped values, initialised with the sawtooth. Other seq settings are at their defaults.

I'd expect this to trigger the samples in ascending order but it doesn't, it keeps playing the lowest sample. I've tried various other combinations of settings for the seq but nothing seems to get the desired result of playing back the samples in ascending order on playback. Am I missing something?

No, the random is in fact a noise function, which is somewhat different from true random behavior.

Now you mention it, I seem to remember you posting something once about implementing true random behaviour sometime in the future. Or did I dream it?

[elcallio]

Did you remember to set the step lfo to "step" instead of "cycle" (next to the "init" button)? In cycle mode, a full cycle will take 1/4 note. In step mode, a single step takes 1/4.
Quick test here works as expected. I.e. a tempo-round-robin.

[IXIX]

Did you remember to set the step lfo to "step" instead of "cycle" (next to the "init" button)? In cycle mode, a full cycle will take 1/4 note. In step mode, a single step takes 1/4.
Quick test here works as expected. I.e. a tempo-round-robin.

A picture's worth a thousand words they say...


https://dl.dropbox.com/u/8876198/Misc/TX01.JPG

With those settings, it just plays the bottom sample eight times.

[elcallio]

Weird. I assume the group settings are for the group into which the matrix is mapped?
One thing though: is the transport playing? Some DAWs will not give proper time/position info when stopped. That is quite a drag. I've made a continuous LFO:s play as expected even when stopped, but tempo synced ones will not shift their start point unless the transport runs.

[IXIX]

Weird. I assume the group settings are for the group into which the matrix is mapped?

Yes.

One thing though: is the transport playing? Some DAWs will not give proper time/position info when stopped. That is quite a drag. I've made a continuous LFO:s play as expected even when stopped, but tempo synced ones will not shift their start point unless the transport runs.

Yes. I set up a simple sequence of eight quarter notes (C3) in REAPER. I hit play and it just plays the bottom sample eight times. I'll send you the project.

[elcallio]

Ok, something weird is going on either with the position/tempo calc or the seq itself. I'll look into it some more and keep you updated.

[IXIX]

Ok, something weird is going on either with the position/tempo calc or the seq itself. I'll look into it some more and keep you updated.

Oo! Did I find a real bug this time? Thanks for looking!

[IXIX]

Hi Calle,

Just trying out the latest beta. I saw this...

- Fixed trigger values for LFO/SEQ not correct when used as matrix input

,,,in the changelog. Is this intended to fix this odd behaviour? If so, I'm sorry to report that the odd behaviour persists. My test project still only plays the bottom sample.

[elcallio]

Hi Calle,

Just trying out the latest beta. I saw this...

- Fixed trigger values for LFO/SEQ not correct when used as matrix input

,,,in the changelog. Is this intended to fix this odd behaviour? If so, I'm sorry to report that the odd behaviour persists. My test project still only plays the bottom sample.

No, sorry, your issue is related to sync. The issue mentioned here is related, but not the same. There is still a sync issue I have not had time to fix. But I will. Promise.

[elcallio]

Fixed at http://www.kvraudio.com/forum/viewtopic ... 44#5233744