terrains and textures are kind of limited. There are some tricks: eg: use multitexturing.(Edit: seems I was wrong with some info about alpha layers, so removed).
Some people tried to frag terrains, so they would me made of individual pieces that can be mapped individually. But as far as I remember this didn't work because it wasn't possible to completely hide the seams between the pieces.
Today most people use Mesh terrains instead. It's a technic named "alpha splatting". Have a look at the FLE open source project as seen in the toolbox of this site. Other tools (FLE commercial, TED, ALE) are using the same method. I would however suggest to implement your own LOD system for these meshes (Level Of Detail: depending on the distance camera to the terrain mesh, a version with reducted polygon count will be used, there may be a couple of versions where only one of them is not hidden at a time).
Although I have to say, Alpha Splatting involves Alpha and you will need to fix "Z-fighting" artefacts when you use it.
As long as you don't need more than 2 textures, you may try the multitexturing approach instead.
Some people tried to frag terrains, so they would me made of individual pieces that can be mapped individually. But as far as I remember this didn't work because it wasn't possible to completely hide the seams between the pieces.
Today most people use Mesh terrains instead. It's a technic named "alpha splatting". Have a look at the FLE open source project as seen in the toolbox of this site. Other tools (FLE commercial, TED, ALE) are using the same method. I would however suggest to implement your own LOD system for these meshes (Level Of Detail: depending on the distance camera to the terrain mesh, a version with reducted polygon count will be used, there may be a couple of versions where only one of them is not hidden at a time).
Although I have to say, Alpha Splatting involves Alpha and you will need to fix "Z-fighting" artefacts when you use it.
As long as you don't need more than 2 textures, you may try the multitexturing approach instead.