Transform maths

Rotate an object around another

// here in this example we are running this code on tick
// RelativeLocation is 100, 0, 0 in this example.
 
Rotation += FRotator(0, 1, 0);
const FVector CenterLocation = GetActorLocation();
RotatedLocation = CenterLocation + Rotation.RotateVector(RelativeLocation);

In red its CenterLocation and in green RotatedLocation

Transform world/local conversion

World to local Use Transform XXX

Local to world use Inverse Transform XXX