Terrain tile performance 1 bigger tile vs more smaller tiles

[Exkr_1]

Hi there,

no idea if someone can answer this one but I will try.

Say you have a 4096x4096 terrain, no textures, no vegetation and so on, just plain terrain (shadow off).
Extra is one directional light and a Main Camera. FPS is on my PC after build at 1400 FPS with this setting

Here is the Problem:
If you split that terrain up into tiles, say 512x512, reducing Heightmap Resolution in relation and so on too and build a terrain grid 8x8 to get 4096x4096,
the performance drop to around 600 FPS with my Setting (over 50% less performance).

On Wireframe in the editor you can see that the tris are the same on one terrain tile even if it is 4096x4096 or 512x512, this doesn’t seems to Change if you lower the Heightmap Resolution. So you actually have more tris and verts on this 8x8 terrain tiles as you had on one bigger terrain tile before.

Question:

Is there a way to reduce that. I want to get to the same tris/vert count on this 8x8 grid as I had with one bigger terrain tile.

[ChrisTchou]

Hello!

Do you know if you’re CPU or GPU bound at 600 FPS with the 8x8 grid?
From my experience I would expect that it is actually the CPU overhead of those 64 Terrain tiles that is causing it to slow down, more than the GPU cost of rendering them…

-Chris

[Exkr_1]

Hi Chris,

I can say that CPU Main thread is going up. I put a screenshot in, its a really easy to do example, takes 5 minutes in Unity.

I made it because this one is bugging me in my main project and I wanted to see if this is a Unity related problem or Asset/User fault.

I mean if it is a Unity related problem the whole tile system is not useful at the moment.
Some suggestions or something that is worked on?

Stephan