From Divinity Engine Wiki
- query GetSurfaceSize([in](GUIDSTRING)_Target, [in](INTEGER)_SurfaceLayer, [out](INTEGER)_SurfaceSize)
Returns the size of the surface type on layer _SurfaceLayer in which _Target is standing. Valid values for _SurfaceLayer are
- Ground layer
- Cloud layer
- Success/Failure: Fails if _Target is NULL or does not have a position (e.g. in an inventory), if no level is currently loaded, if _SurfaceLayer is not valid, or if _Target is not in any surface that belongs to _SurfaceLayer.
- _SurfaceSize: The number of cells occupied by the surface.
- This query is new in DOS2 Patch 5