Landscape actor memory size on disk

Development World Creation
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1

Hi,

I’m developing an open-world game and yesterday I made my first attempts at importing a landscape from World Machine to UE4.

As my game design asks for huge levels, I was concerned with not only the landscapes visuals (which looked 100% ok for me in UE4, even without textures yet) but with the memory sizes on disk, loading times etc. I followed some nice links with guidelines for importing terrains from WM into UE4:

https://forums.unrealengine.com/deve...ss=&viewfull=1
https://forums.unrealengine.com/deve...d-Composition=
https://docs.unrealengine.com/latest...dscape/Custom/
https://docs.unrealengine.com/latest...landscapesizes
https://docs.unrealengine.com/latest...ion/index.html

All of the links above were very helpful. So I picked up a scene I had here in WM and changed some of its settings to fit the exporting<->importing standards. I exported a 8129 x 8129 (resolution) terrain heightmap in PNG 16-bit, as recommended - the terrain was set to 8.129 x 8.129 km in WM.

Then, in UE4 I followed the settings for landscape suggested in the fourth link above (recommended landscape sizes):

Overall size, Quads/section, Sections/component, Component size Total components:
8129x8129 127 4(2x2) 254x254 1024 (32x32)

It went smoothly into UE4, no errors - this was great, for a first try.
The thing is: I checked the map size after saving it and it was 433.558 Mb on disk.

  • So my first question is: is that a standard size on disk for a landscape of 8 x 8 km? (8.129 x 8.129 km, to be more specific)

I then tried importing another WM terrain into UE4, a 2017 x 2017 one, with same average resolution (1m / pixel). 2.017 x 2.017 km in WM. It takes 26.55 Mb on disk. So, I made some rough calculations, approximate values, and it gave me ~2.6 Mb / km in each side (some more, but this is close).
2.6 x 8 km = 20.8
20.8 x 20.8 = 432.64 (not 433 Mb, but close, ok to have an idea of sizes)

  • My second question: is this kind of a standard relationship in Mb on disk <–> Km of landscape in UE4 (if using this average resolution from WM of 1m / pixel)? And if so, is there any way we can reduce this size on disk without reducing the resolution? I need to ask this before going to reduce it.
    1m / pixel (1m / terrain quad) felt ok in UE4. Less than that I fear may feel blocky, specially in sudden changes in relief.

Thanks in advance. Any help will be very appreciated. Some screenshots attached to help see the results. Nothing special, only messing with terrain resolution etc.

Thanks in advance,

2

Bump…

3

Regarding your first question, yep, that is the proper size. Don’t forget to account for weightmaps in addition to the heightmap itself.
As for second question, nope, you can’t.

On a side note, Using 8k heightmaps in a world is beyond overkill. You should consider splitting the world using world composition.

4

Thanks for the reply.

After posting this question, I tested using 4033x4033 and 2017x2017. It holds well enough in the distance. I’ve seen recommended sizes for landscape tiles when using world composition on the forums etc that suggested using 1000x1009 or 505x505.

Which heightmap resolution (average, nice visuals) would you recommend for a 8 x 8 km landscape (world machine’s topology scale) in UE4?

5

Depends on what resolution in vertices per meter you are after. Generally 1009 seems good.

6

That’s what I was asking for. Thanks.