From Divinity Engine Wiki
- query DrawSurfaceOnPath([in](GUIDSTRING)_OwnerObject, [in](GUIDSTRING)_FollowObject, [in](STRING)_SurfaceType, [in](REAL)_Radius, [in](REAL)_Lifetime, [out](INTEGER64)_SurfaceActionHandle)
Draws a continuous line of width _Radius of surface type _SurfaceType behind the _FollowObject as it moves, with lifetime _Lifetime. The _OwnerObject parameter can be used to set the owner of this surface.
- Success/Failure: Fails if the _OwnerObject or the _FollowObject don't exist or are null, or if the _SurfaceType doesn't exist.
- _SurfaceActionHandle: The index of the Surface Action. This is an identifier necessary to stop drawing the surface again.
- This routine currently does not work correctly if _Radius is >= 2.0
- The _Lifetime only starts ticking after StopDrawSurfaceOnPath has been called for the _SurfaceActionHandle. It can be -1.0 to make the surface permanent.