Hi Joe – welcome to Holygon forum!
Yes, you are right.
Specifically, regarding Fence:
First, we should understand what Fence is.
Fence is simply a property of an edge.
The edge must exist in your terrain mesh.
When an edge is fenced, it will tell other Landshape commands to treat this terrain edge in a special way.
This is all that there is to a Fence.
While a simple concept, this can be very useful.
Before you may Fence or Unfence edges that exist in your terrain mesh, first, you need to ensure that these edges actually exist in your terrain mesh.
To Embed an edge, an edgepath, or any selection of edges, first preselect the edges in a separate geometry control group. Then, run:
Landshape > Pick > Embed
At the time of writing this, in Landshape version 0.11, you can access commands Fence and Unfence via Landshape’s Prop menu.
To Fence any number of particular individual edges which are already embedded in your terrain, first enter inside your separate control group, and among its geometry, here pre-select the exact edges that coincide with your pre-embedded edges. Your control group geometry should typically be hovering above or below your terrain, at any elevation, but coinciding in plan with your corresponing terrain edges. Now, run:
Landshape > Prop > Fence Edges
This should turn on the Fence property in the corresponding terrain edges.
To Unfence any number of particular individual edges which are already embedded in your terrain, do the same as above, but instead run:
Landshape > Prop > Unfence Edges
This should turn off the Fence property in the corresponding terrain edges.
Remember to always keep your geometry control groups on a separate tag. This helps you to quickly hide and show your control group geometry, and reuse its edges and other geometry to communicate with and edit your Landshape terrain.
Note that currently, there is a special command that first embeds, then also enfences, called Embed Fence. Currently, it is available via:
Landshape > Pick > Embed Fence
Please note that at the time of writing this, team Holygon is working on improving how Fence works.
Starting in Landshape update 0.12, planned for release in the first quarter of 2026, Fencing will become more robust, and assume a more central role.
Starting from Landshape version 0.12, the Fence property will become more persistent. Fenced edges will stay untouched across remeshing. We will add a new tool that allows batch fence and unfence. Also, the Fence and Unfence commands will be more accessible.
Please note that version 0.12 will also change the details on how to work with fencing. Thus, from version 0.12 on, several details given in the steps above will likely change.
But the fundamental concepts will stay the same.
Team Holygon also plans to publish several new Youtube tutorial videos, that show how to combine Mesh, Fence, Unfence and other commands into powerful new workflows.
Thank you for being part of this journey!