Resource size optimization of huge SM

I am working on a rather huge world. I have been exporting Heightmaps from Worldbuilder to make my landscapes shapes. The landscape pieces are 2017x2017(~2x2km) resolution with 32x32 quads. To make it easier on the system I exported the highest LOD from the Landscapes as FBX and used them in Level LODs.

It works well, but I notice that each Landscape LOD FBX has a rather high Resource size(RS). They have 2048 tris and 1089 vertices and ~630 kb each in RS, and physical size same as the landscape(~2x2 km).

But if you look at much smaller(in physical size) meshes, for example the table in starter content, it has about 4300 tris and 3900 vertices and is around 320 kb in RS, with an extent of 125x125 cm.

What I heard is that the reason for the bigger RS on the physically bigger meshes is due to each vertices need more memory to store its position. Which is understandable, but is there any way to fix/optimize this?

630 kb might not sound much, but the goal here is to have around 650 of these Landscape LODs so it would mean about 410MB of RAM…

Did you figure this out? I’m wondering if you have a 100KB cube, then you duplicate it 500 times, would all of that count when you have a final product? For instance, on Android, it has a 50MB package limit, so does that mean 500 cubes would hit that package? Or does a published game just have one asset and any duplicates are not included in the memory pool.

No, I haven’t got any useful information anywhere about this. How UE actually compress static meshes etc.

I’m thinking it wouldn’t go into ram if you culled them out. And what’s weird is that if you check the statistics, if you have 1,000,000 duplicates of a mesh, the resource size is still the amount of just one static mesh. I’m thinking they optimized it or something in terms of the size of the file. Grant it, if you had 1,000,000 meshes, you would still have to deal with vertex count.

When I say resource size I mean the space the asset takes on the HD, not its impact on ram in game. But bigger asset sizes of course also means taking more space on RAM. I am not duplicating the same mesh, it is multiple different meshes.