Source Info

How the framework keeps interactable objects independent of the player.

diagram_sourceinfo.svgThe Source Info struct and where it originates

The problem it solves

If a grabbable object asks "which hand grabbed me?", it has to know about hands — and then it only works in VR. If it asks "who selected me?" and the answer is a pawn class, it only works with that pawn.

The struct

ST_SourceInfo carries three things: the pawn that acted, the component that acted, and the component's identifier name. It is produced by BPI_SourceInfo.getSourceInfo, which all three ability base classes implement.

Every interaction call takes it as a parameter. A target therefore knows exactly who acted on it, with enough detail to distinguish left hand from right, without ever referencing a pawn or controller class.

Using it

• FL_Haptics.Haptics_Effect takes Source Info and plays on the correct hand automatically.
• getSidesFromAbility resolves Source Info to one hand or both.
• The identifier lets you distinguish, for example, a fingertip overlap from a whole-hand overlap using Allowed Identifiers on BPC_Interaction_Overlap.