1. Remove the +1 option from the World Machine project settings.
2. Height Output in World Machine is used to export height maps, and Bitmap Outpout is used to export textures
3. In Unity3d, create a Terrain in the scene, select Terrain Setting in the Inspector and click [Import Raw..]
4. Set the terrain size
5. Set the terrain height
The generated map has no texture yet
6. Drag the exported image into the Unity project.
7. Select Paint Terrain in Terrain's Inspector, switch to Paint Texture, and expand Layer
8. Click Create... to create the layer
9. Select the layer, expand Layer Properties, and set Size in Tile Settings
It's done here.
