Merging multiple terrain objects into one

Hi,

I have only one question:
Is it possible to merge multiple terrain objects into one?
I know there is such way as exporting terrains height maps and merging them into one in photoshop/gimp, but the major problem with this method is that the terrain height maps will be in exported certain resolution, and merging them into one height map will multiply the overall resolution of the heightmap so it wont be usable anyways, becouse unity suports resolutions up to 4097x4097, so I don’t even bother trying it.

I really do need high-poly terrain for my project but I can only achieve this by creating multiple terrains with multiple heightmaps.

Is there any other solution possible?

For highpoly terrain this is the way to go, having multiple high-resolution ones next to each other. With the current system there’s not even a downside as editing respects neighbours. Other options are using voxel terrains which would not be very highpoly for performance reasons and just using plain meshes which you’d probably use in combination with some type of LOD or rolling your own terrain system.