Poor performance from Landscape, any tips?

Legacy UDK Programming and UnrealScript
1

So, I believe I’ve tracked down the source of my awful frame drops, it’s the Landscape, only deleting the Landscape will solve the framerate issues.
Now I’m about to just remake the whole thing given I have another (somewhat simpler) Landscape in another level that works just fine, but I figured I’d ask before I throw away all that work.

Does anyone have any tips/tricks for enhancing performance from landscapes, because I’ve tried these and they’re not responsible

  • it’s not the meshes on top
  • it’s not the game engine in general
  • it’s not the landscape’s material and shaders, default material is just as laggy
  • it’s not the landscape object’s settings, scale, or anything else that hasn’t changed anyway since the old demos

Unless there’s some trick or hidden quality setting somewhere I’ll just give up, consider it possessed and remake it from scratch.

2

I use a massive landscape (total size quads == 4033x4033) with a complex material with lots of instructions and it is very performant.

Check your section size and component sizes. Also your LOD bias (all in the landscape edit tool).

If you are lighting it with a dominant directional light, check your cascades radius, etc.

3

Also, if you have used the foliage tool on the landscape, it’s likely that is causing the issue (which is why you may be seeing performance increase when deleting the landscape, as this would also delete your foliage).

If it is your foliage causing the issue, check your cluster counts per foliage type. You want to choose an appropriate cluster size and radius depending on how dense a particular foliage type is on your landscape. Each cluster causes a draw call during runtime, so try to balance your instance count with your cluster count to find the sweet spot.

4

Thanks a lot, it was the foliage, creating enormous lag even in the editor window for some reason, honestly the whole thing sounds like a mess and like I’m better served creating a ‘bunch of lowpoly trees’ static mesh and manually placing that around.

5

@ciox The foliage tool is far more efficient when you have groups of many same static meshes, as it groups them into clusters, with each cluster using only a single actor. This drastically cuts down on draw calls and the number of spawned actors in the world.

It sounds like perhaps you are not putting a limit on your dynamic shadow casting radius and are dynamically lighting all your foliage.

The foliage tool is extremely powerful, so I would advise learning to work with it if you are creating large outdoor maps. You can see the extent to which I use the tool in my game: Subsistence on Steam