Some users have asked on the forum how to do a master output fade or a blackout button in GrandVJ.
In mixer mode, you could always assign a black image and assign it to layer 8 but people using the synth mode (or if you simply don’t wanna waste an additional layer) have to use some tricks to acheive it.
The key is to use the master brightness and contrast on the master: If you pull the brightness to zero and the contrast to the maximum, all output will be blackened.
So we want to go from the “normal state”:
To the “black out state”:
Using a single controller or key.
In this tutorial, we’ll suppose you want to use a midi controller to go gradually from one to the other, providing a master fade functionality.
Let’s start by mapping the brightness control. Right click it and choose “Midi mapping…”. This will bring the MIDI mapping dialog:
Click on “learn” and start moving the knob you want to assign to the master fade out. By default, it will control the brightness to it’s full extent (0-100%) over the controller range. However, our “normal state” needs the brightness to be at 50 percent so we’ll tweak the range so that the Max. Value is 50.
Close the dialog. Now moving your controller will move the brightness slider from 0 to the default position.
Now let’s tweak the Contrast. Right click it and select again “Midi mapping…”
Click “Learn” again and move the same controller you assigned to the Brightness. GrandVJ allows you to map the same controller to multiple functionalities, so that not an issue.
Now you want that when the brightness is full (the controller is to its maximum value), the contrast is to zero and that when the brightness is zero, the contrast is full. That means you want to invert the behaviour of the contrast. To do so, it’s very easy, simply put 100.0 as Min. Value and 0.0 as Max. Value.
Now press ok on the dialog and you will have a dedicated control to fade the master output.
Of course, you can also assign this to a note event or a key and you will have a black out switch instead of a gradual fade…