r.VolumetricFog.HistoryWeight
VarUnreal Engine Var console variable.
rVolumetricFogHistoryWeight
Description
How much the history value should be weighted each frame. This is a tradeoff between visible jittering and responsiveness.
Usage
r.VolumetricFog.HistoryWeight [value]Set via the console (~) or in DefaultEngine.ini / DefaultGame.ini.

