The S.T.A.L.K.E.R. 2 team has confirmed that GSC Game World has shifted from the X-Ray Engine altogether and will instead use Unreal Engine to better support the mod community.
GSC Game World
STALKER 2 announced, set to release in 2021
S.T.A.L.K.E.R. 2 has been announced, will be the first new game released in the series since 2010. Following in the footsteps of its predecessors, S.T.A.L.K.E.R. will once more have players adventuring into “The Zone” and facing down the lethal threats that await them.