This tutorial will show you how to apply a series of textures to a terrain model in Blender. For this example I'm using a model of Wellington city, New Zealand.
- Download all the files listed at the bottom of this tutorial
- Open Start .blend
- In the Properties shelf >> Shading >> Change Multitexture to GLSL
- In the Properties viewport >> Textures >> Add new texture
- Change Type from Cloud to Image or Movie
- Scroll down to Image >> Open >> Navigate your filesystem and find Wellington - Colour Map.png
- Repeat steps 4 to 6 for each of the textures you downloaded
- Toggle the visibility of the textures by clicking on the check boxes in the list of textures at the top.
- To improve the quality of the model, in the Properties viewport >> Object modifiers >> increase the Multiresolution modifer Preview setting from 8 to 9 or 10
Discussion about textures
The textures for this tutorial came from Koordinates. I used QGIS to export them as bitmaps. The colour map was created procedurally from the heightmap, the rest were from vector outlines of roads, land parcels, and buildings. This method works, but it is not the only method, nor is it neccesarily the best method. To be more efficient with RAM and CPU it would be prudent to merge the textures using a programme such as GIMP. Also, use a texture size that has dimensions that are a power of 2, such as 64x64. 128x128, 256x256, 512x512, 1024x1024, 2048x2048, 4096x4096. For more depth, check out the Blender documentation on Image Textures.