How to efficiently render large and detailed terrains?

Support Modeling
1

Hi All,
I’m new to the forum and to Blender overall. I’ve looked through the messages posted on this site, as well as on other sites in search of an answer to my question.

I’m interested in using Blender to render large and detailed landscapes and terrains based on high resolution topography. I’ve been relatively successful at rendering terrains up to around 12,000,000 faces (matching the resolution of my topography), but with high resolution topography this can still be a relatively small area in real space.

My process is as follows: I use a grid mesh that’s subdivided at the time of creation with a displacement modifier and an image file to get the topography I’m after. Pretty straight forward thus far. Most of the tutorials and examples use relatively small samples of elevation data so reaching the upper limit of the number of faces in the mesh is never a problem.

Are there and strategies for creating terrain, perhaps in stages, to reduce the load on the computer?
For instance, If I were using 10 meter resolution data as the basis for my terrain, and wanted to render an area 100 km x 100 km, that would result in a mesh with 100,000,000 faces. Which is a bit more than my computer can handle.

If you can point me to any discussions that have covered this topic, I’d really appreciate it. And if you have an comments, thanks in advance.
-Joe

2

i like to use the height map as a bump map, this really helps fill in the gaps and requires much lower resolution. its a cheap trick but it works good enough for games.

perhaps you could do some kind of high to low res bake type thing to get some custom normals. do several smaller areas then combine the normal map to cover your area.

3

Thanks for the ideas. I’ll try some experiments with the methods you suggest. I realize that I should have stated my goal; I’m using Blender to make maps, so I am interested in preserving details as much as possible.