We don’t currently have a nicely exposed interface for manipulating a force feedback effect dynamically. You could (somewhat painfully) create a number of different force feedback effects in the content browser and change which one is active based on the distance.
I will ensure that we have a task included for exposing the ability to apply/manipulate a dynamic force feedback effect.
I would like to set the rumble (Vibrate) function of gamepads with a strength that == distance to other actor, wondered if there was a way to access it or adjust it.
it would be cool if the audio functions just had a tick box that could be set that turns them into force feedback effects. than you could use .wav audio files to control the rumble and it would be easy for sound designers to work with. sound nodes already adjust with distance, so treating vibration as a type of sound would make things simple.
A blueprint node to dynamically manage force feedback has been submitted (https://github.com/EpicGames/UnrealEngine/commit/faf1229db60098d47f3fc7774e2f70f676ac829d) and will be part of the 4.4 release.
The mechanisms that it uses on the PlayerController could be used to manage force feedback dynamically from C++ as well, though there aren’t any utility functions in place to do so at the moment.
We don’t have access to the output of a sound at the engine level as we delegate that work off to the hardware and tying it to a SoundCue would be even more difficult in our current construct as its eventual output is (potentially) the combination of multiple wave files.
A number of our artists and designers have asked in the past for a generate curve from wave function that they could use anywhere we use curves (which would include force feedback), however, we haven’t had the time to build that functionality to this point, but it is somewhere in the backlog of things we’d like to provide.