Export to Unity

Follow this workflow guide to take your terrain and texture splatmaps into the Unity engine.

Terrain into Unity

Within World Machine

1. Place a Height Output device into your world. Wire the terrain you wish to export into the device’s input.
2. Choose your export format within the File Output device. You should use the RAW16 format.
3. Build your world and export all files. The “Export Terrain files…” option from the File Menu provides a central location to do both.

Import into Unity

Luckily, Unity makes it easy to import a terrain. The exact process depends on the version of Unity you’re using, but it goes something like this:

Simply follow these steps:

1. From the GameObject menu, choose “3D Object” -> “Create a Terrain”
2. From the terrain properties (Texture Resolution) subpanel, choose “Import Raw”
3. By default Unity considers both 8 and 16bit RAWs to use only the .raw extension, whereas World Machine uses .r16. Change the import filter to “All Files” and navigate to where you saved your exported World Machine .r16 file. Select it.
4. In the Import dialog, make sure the depth is Bit16 and the byte order is changed to Windows, then hit Import

Watch out: Unity interprets raw heightfield origins differently from World Machine. your terrain will appear to be flipped on the Y axis! One way to fix this is to add a Flipper device in World Machine just before your Height Output and turn on the Y-axis flip. This will make the terrain appear properly.

Later versions of Unity also have an option to flip the Y axis, which you should check.

You should now have your Terrain inside Unity! You will probably have to play with the Terrain Scale to get the size to fit correctly into your scene.

Texture export to Unity

Unity has built-in support for texture weight-maps (called “splat” maps). You can create multiple layers of terrain textures and paint each one onto the terrain.

This simple workflow provides a way to import the texture splatmaps created within World Machine into Unity. Please note that although this method works for basic Unity Terrains, advanced users may require their own techniques.

Within World Machine

1. Create your terrain texturing masks based upon whatever criteria you want (for example, using Height Selectors, Slope Selectors, Erosion masks, etc).
2. Use the Splat Converter device to control your splatmaps and enforce proper weighting (sum-to-one, etc). For more details and an example world using the Splat Converter, see the “Splatmap Converter.tmd” example file included in the World Machine Examples under “New Examples for WM 2.3\Techniques”
3. To convert your individual maps into a bitmap, wire them into a Channel Converter, which will produce an RGB image for the first three channels. The fourth will be used as the Alpha channel of the bitmap. Wire the resulting maps into one or more bitmap output devices to create a 4 channel splatmap. If you are using more than 4 textures, simply create multiple bitmap outputs and adjust the Splat Converter accordingly.
4. Build the world and export your terrain and splatmap.

Within Unity

Unity doesn’t provide a built-in way to replace the texture layer data with your custom splatmaps. To easily import a splatmap from World Machine into Unity, you’ll need a simple Unity script that can import and replace splatmaps.

Download the script provided below and extract it into your project folder. Make sure that ends up in the YourProject/Assets/Editor folder. If Unity can find it, it will compile the script and the Terrain menu with the replacement script will appear.

Download Unity Splatmap Replacer script

All Done!