Difference and Merge Operations

The following diagrams illustrate how Difference and Merge operations can be applied to surface DTMs. A topographic surface (A) and a pit wireframe (B) were used in the examples shown. The function expects topography to be the first surface selected.

Surface difference A-B:	Surface difference B-A:
Surface merge: Effectively, this is Difference (A-B) and Difference (B-A) merged together.