Almagan - A volcanic island in the Northern Marianas.

It turns out that making copies of real-world islands with Blender is fairly simple. This webpage shows the steps required.

The only step not mentioned is that, once you have created the mesh, you should click the "Apply" button to "bake in" the elevations. (Before doing so, I would suggest saving the Blender file in a safe place in case you want to make other changes in the future.)

You can obtain heightmaps from around the world from the terrain.party website.

You can obtain the real-world texture using Google or Bing maps. In the case of an island, you will want to create a transparent texture. This means you have to get rid of all the ocean areas. Using a transparent texture allows you to create an island shape that is far more detailed than the underlying mesh.

Here are the maps for Almagan, including the heightmap (left) and the texture map (right).

To recap, the steps are as follows:

• Download a heightmap from the terrain.party website. You want to use the "merged" heightmap.
• In the Blender 3D window, add a 1 ft X 1ft mesh grid with an odd number of points (161 points is roughly a 10 meter dem).
• In the Texture Properties (last) section, open a new texture.
• In the Image/Settings subsection, open the heightmap.
• In the Mapping subsection, select "Extend".
• In the Modifiers section, add a Displace modifier.
• Select the Texture which you created above.
• Change the Midlevel value to 0 and the Strength to (e.g.) 0.5.
• In the 3D window, select Edit and select all faces.
• Select the Face option and select "Shade Smooth".
• Save the Blender file in a safe place in case you want to make additional changes in the future.
• Select the "Apply" button to "bake in" the changes.
• The file will have a blank material, which you can use for your texture.
• Create a texture for the mesh and load the texture into the material.
• Use the UV Editor to apply the mesh to the mesh.
• To use the mesh the three.js detach the texture from the material so that the mesh is blank.
• Export the mesh as a glb file. It will have the UV instructions attached.
• Flip the texture vertically and save to the three.js texture directory.
• In your program, load the mesh and the texture and combine them.
• Resize the object to the appropriate dimensions.

While the process of creating an island is fairly straightforward, the greater challenge is finding a small uninhabited island that is well mapped. In general, the smaller the island, the worse the mapping. Many uninhabited islands are not even mapped. And if you are lucky enough to find a small well-mapped island, you will likely have trouble finding a good image. Even with Google or Bing, many of the images of these islands are substandard.

But, if you find one, the results are amazing. The shaded texture will make the map seem higher resolution. We captured the textures from Google maps at the 500 foot setting. To save space, we suggest using a texture which is 1024 X 1204 or 1024 X 2048 and which has 32k colors. This kept the size of the textured island to less than 1mb.

Giaros - An island in the Aegean, southeast of Athens. The excellent shading greatly enhances the shape of the mesh. In your simulation, be sure to align the island so that the shadows are away from the sun.

One you have found an island, you can make changes to the island. For example, you can resize the island. Or you can edit the mesh of the island to add a runway. However, if you plan to "harden" the island surfaces, you will want to minimize the changes to the mesh. This is because you will want to use the heightmap to define the elevation.

Almagan with a runway.