[DONE 1.12] Base point for fx ,add mode additive ,subtractive,relative

[giancarlo]

Please enhance the way fx are applied to the relative position or color or any parameter,make it possible to allow the fx to add from current position or to subtract from current position most of the time I need to apply these types of features to an fx,not the fx just running on top or bottom of my pan tilt values. High values low values.
Thank you!

[denishessberger]

Happy to announce that this will be part of the next release.

Denis