Hey leo. With the new version, both tiles and units share a common blueprint parent called BP_GridActor, which is used for calculating the actor’s GridIndex, snapping to the grid etc. If you simply reparent BP_Unit to Pawn instead of BP_GridActor, BP_Unit will no longer have access to the GridIndex variable, which is used in several blueprints. You can add the functionality from BP_GridActor manually back into BP_Unit, of course, but then you need to go through all blueprints and change the old GridIndex reference with the new one. The compiler will thankfully help you with this by marking all such occurences with an error.
Another possibility is to reparent BP_GridActor to pawn. I have tried this and it seems to work fine. This will add a lot of unneeded functionality to things like BP_GA_Tile, but I don’t think it should have any real impact on performance.
This is if you just need the pawn functionality, though. In the earliest versions of the toolkit, BP_Unit was based on pawn. In later updates, up until a couple of updates ago (when I changed the parent to Actor), it was rather a child of Character. If this is what you want then it becomes a bit more complicated. Character comes with a capsule collision component that cannot be removed and a skeletal mesh component that cannot be unattached from this capsule component. If you want to use the skeletal mesh included in Character you cannot use my setup in BP_GridActor where I use a custom scene component as an “anchor” for the grid snapping functionality. Instead you have to use the capsule component, which annoyingly has its origin in the center of the capsule and not the ground. Because of this you will need to add offsets to account for this in any blueprint that changes the unit’s position on the grid.
It was because of all of these extra annoyances and clunky workarounds that had to be coded in to more easily allow for using UE4’s character movement component, which I consider to be a bit of a corner case, that I decided to use Actor as a base instead. If this is what you want to do you have two options: Either code it in like it was done in earlier versions (you can download an earlier version and search the blueprints for CapsuleComponent to find all such places) or you can cheat. By cheating here I mean using one character for all your Character movement component stuff and when you want to change to ATBTT-style turn based combat, hide the characters and replace them with BP_Units using identical skeletal meshes.
Without knowing more about exactly what you want to achieve, these are my best suggestions.