Edit existing terrain
To edit a mesh terrain you of course need a mesh terrain to edit.
There are lots of ways to get one, but most often you either reference an existing mesh directly from rhino or you can use the mesh terrain output from one of the other components of the Terrain Tools.
To edit the terrain you first feed it into the [Mesh] input of the "Edit Terrain" component.
You then need to describe how you want the terrain to change. You do this by feeding the component one or more curves that describe how you want the terrain to be shapes in some area. This is exactly like when creating a terrain from scratch but the edits can be isolated to smaller areas of the whole terrain if you want.
No need for curves where you dont want the terrain to change.
The component also wants a [Res] input. This is also the same as when creating a terrain from scratch and describes the resolution to use for the curves you use to edit the terrain. Be careful that you input numbers that make sense in regards to you files units. Dont input millimeters if your file is in meters.
It is possible to create areas with finer detailing by using smaller [Res] values in subsequent Edit Terrain components.
More on this in the "Chaining components" guide.
Here is shown an example where we have added two curves making up a road along the terrain:
Notice in the last step that we used a radius of 6 meters. This tells the component to only edit the terrain which is closer than this.
You set the [Radius] input to the distance you want the the curves to have an effect.
Note that this too is unit sensitive. Say for intance that you input "5" into the [Radius] input in a rhino file with meters as units. The curve will then change the terrain and control its shape but only withing 5 meters of itself.
In the following example we have added another Edit Terrain component after the last one to add a path to the terrain.
Notice that the [Res] input is not only affecting 3 meters and makes a smaller edit to the terrain.
Also notice that the road and the path curves cross each other.
There is no need to seperate the path area as it only affects the terrain "after" the road has edited it.
Therefore it is easy to plan the heirarchy of your terrain edits.
You can add as many terrian edits as you want. More on this in the "Chaining components" guide.
And thats it. You can now go and edit the digital world as you see fit.