Well, as I have mentioned several times on the forum, I have traditionally scattered rocks and trees as “instances” using the Blender Particle System on a terrain I have created by various other methods.
Now with Blender’s Geometry Nodes I can create the terrains and add the instances. This first part is about the steps I use for creating the terrain with Geometry Nodes.
1: Create a simple plane, scale to the size I want, then subdivide. In this example the plane is 80x80 metres, and subdivided 30 times - so 32x32 vertices for a total of 1024 vertices. See an example here:
2: After I create the plane, I go into the Geometry Nodes Tab and add a geometry node. See Image 1. A more detailed explanation is in Image 2:
A: the basic Geometry node with two nodes inserted - a) a get positions node and b): a smooth shading node.
B: the crucial nodes drive the “offset” randomly moving the vertex positions. and this is done using a noise texture - Voronoi, Noise, or Musgrave.that move the vertices along the normals to the faces (built in).
C - two nodes to move the position of the texture, allowing movement of the texture to suit needs.
D - two nodes to keep the plane along the Z = 0 axis.
E - to output the scale to the geometry Positions.offset.
As it stands, you see the terrain in “Object Mode” but in “Edit Mode” you see the vertices of the subdivided flat plane- Images 3 and 4.
At this point, I had no idea what to do next so I just did an export using @JCPalmer 's babylon exporter - and it worked (the example above is just the export) but if you wanted to alter the mesh (eg create a proper walking path or river) then something extra is needed.
The answer is to open the Geometry nodes tab, put the mouse in the 3D viewport window, hit "Ctrl + A" then in the menu that opens choose “Visual Geometry to Mesh” and now in “Edit Mode” the vertices correspond to the terrain and can be altered in various ways. Image 5
The texture on the terrain uses the Babylon script for “mixing” materials.
More to come - adding rocks ?
Stay Safe All, gryff
Image 2: Object Mode
Image 4: Edit Mode
Image 5 Converted