How hungry are terrains?

I have an idea that would require lots of small terrains, maybe only 50m-200m square in size. Would it be acceptable to have each one being a terrain, with whatever overhead each terrain has; or would it be better to turn each one into a mesh, and use a splat map shader to make each one appear like a terrain?

I guess what I'm asking is, what is the overhead of a single terrain, and by how much does that grow when having multiple terrains?

 

Terrains are in general rather ressource hungry. In detail it still also depends on how high you crank the details, which shaders you use and how many textures you blend into each other.

You best individual option here would be to use the profiler and check it out yourself with a quick scene setup that doesn't look good but uses approximately the detail you are aiming for.

As a rule of thumb I'd stay clear of too many terrains. Can you maybe use static meshes instead of terrains if you are going to split up your scene into smaller segments anyways?

 

While working with terrains, I find having many small terrains does not perform as well as a few large ones. With the sizes you want, you probably should go with meshes or even better to use larger terrain.

Also, what is the reason to use such small terrain? Are you thinking something with editing the heights or loading them in and out?

 

Thanks for the answers, that's pretty much what I thought the case would be. I'm going to go with designing using small terrains and use a converter to turn each one into a mesh that can be saved out.

 

If you are going to use an obj export on your terrains think about using a mesh decimation tool like in modo or ZBrush. If you export a terrain it loses the ability to use lower detail on far away patches. Maybe even better yet: Slice it into parts and use Occlusion Culling if you have Pro.

 

Very hungry

 

Well there are also performance tweaks on the terrains settings as will, like pixel error etc. you can also reduce the draw calls of grass by tweaking some of the parameters too. It is hungry, but if you know what to do it's perfectly manageable dependant on the platform.