Oh I didn’t see all these latest comments in this topic ^^
Anyway, +1 for ECS; it’s a good thing IF used in the right place for the right reasons. i.e (not replacing Actor-Components).
I don’t think “re-writing” the whole engine would be necessary. Epic could build ECS from the ground up as a “pure” self-contained environment then build an additional “hybrid” system linking ECS to Actor-Component environment… Where and how to use it would be up to the game developer.
Major problems I see with this tho is that “ECS” cannot contain object and entities aren’t objects either. So that means no support for UFunction, no UProperty, no UStructs, no “code reflection” features, no Blueprint support, no nothing lol