Excavations within a 3D Terrain Model - Rhino 7

This video tutorial goes through the steps to create excavations and cut outs within a 3D terrain model in Rhino. This goes through extracting simple geometries from a terrain, cutting out paths and extracting natural forms such as ponds and rivers. The key steps in this video can be found below:

00:00 - Introduction
00:30 - Extruding a terrain surface into a 3D model
01:36 - Removing simple geometries from the 3D terrain model using 'Boolean Difference'
03:25 - Adding geometry to your terrain using 'Boolean Union'
04:05 - Creating a path within a 3D terrain model
04:25 - Sketching out a path
04:42 - Flattening the path using 'SetPt'
05:05 - Projecting the path onto the 3D geometry using 'Project'
07:43 - Using 'Sweep1' to give a thickness to the path
09:33 - Using 'Cap' to close the sweep object
10:37 - Excavating the path from the terrain
11:10 - Excavating a pond from a terrain
11:20 - Sketching an outline of the pond
12:04 - Modelling a natural pond geometry
13:28 - Using 'Boolean Difference' to excavate the pond