Proposal - disabling fade in and fade out times on VCSliders

[plugz]

Why disallowing fade in and fade out on VC Slider ? Here are some diagrams.

Orange lines are the values of the sliders controlled by the user.
Yellow lines represent the fade in/ fade out multipliers.
Blue bars represent the controlled channel output value.

VCSlider: the fade in time start from the moment the slider is not zero.
This looks nice at start, but if the user does a 2-step increase of the fader(like in this diagram), the 2nd time does not have fade in. I don't know if it should, but since the question exists, it's not good.

The fade in time is totally ignored.
No fade in, but in this case we know this is a manual fade in, the user knows what to expect.


-> Fade in: inconsistent behavior: VCSlider and CueList Slider don't act the same

There is clearly an issue here. The fade out time starts from the moment the slider reaches 0.
This means the fade out time only acts on the last part of the slider decrease.
This is not good.

Manual fade, the fade out time is ignored.
The user knows what to expect.


-> Fade out: inconsistent behavior: VCSlider and CueList Slider don't act the same




-> My conclusion: ignore fadein and fadeout time when starting and stopping a function with a VCSlider.

PR: https://github.com/mcallegari/qlcplus/pull/699

[giacomo]

Hi David and Massimo,
I like the simplicity and consistency of David proposal but will be still possible to use a frame sub-master slider with buttons and timed fades?
In this way one can always start a 2 min fade function and set the level at 80%.
Personally I prefer this coherence than a different behavior on the 2nd movement of a slider, for me it's more clear and easy to remember.

[mcallegari]

Hi Giacomo. This change affects only Virtual Console sliders in playback mode.
So submaster + buttons will still work as they work now.

[mcallegari]

Comments are welcome.

In my opinion, a Virtual Console Slider in playback mode should always ignore the fade out time, but not the fade in.

The two usage cases for fade in are:
- providing a Function with no fade in will allow manual fade in with the desired timing up to the desired intensity (= the slider level)
- providing a Function with fade in allows a combination of target intensity adjustment, while keeping the Function fade in automation. For example one could be interested in having a 2 minutes fade in that reaches just 80% of intensity.
Obviously on a very short fade in this will produce a not nice effect. In that case, the usage of a VC Slider in submaster mode + a VC Button is preferred

[giacomo]

why not the fade out? isn't it weird to have a fader following a time just for the fade in?
(maybe the optimal solution would be that the time it's a property of the slider and every variation would be executed with the chosen fade time)
if it's a problem to have a correct behavior for the sliders then we should prefer for a clear coherency as proposed by David, all the slider kinds should beheave the same. If we record a function with a fade time then we choose if to control it manualy with a slider or timed with a button.
regards