Hi everyone,
I’m trying to optimize a forest built with assets from the FAB Marketplace in UEFN. While it runs at around 50–80 FPS on PC, it drops to about 5 FPS on mobile, even with a moderate amount of foliage.
I’ve looked at maps like The Forest Guardian by Epic, which runs at 20–30 FPS on mobile, and I’m wondering what techniques or settings might help me improve performance in my own project.
The meshes I’m using from FAB are referenced for UEFN, meaning I can’t edit LODs, materials, or collisions — they’re locked.
Would it be better to try requesting a refund and buying the UE version instead, so I can optimize the assets manually?
I’d really appreciate any advice or tips — I’m stuck and could use the help.
Thanks in advance!
Heya,
In my opinion, I think it helps a little bit to start turning the decimal places into the nearest whole number.
Cut down on all the extra digits.
If you work by snapping to a 16 grid, I believe (no proof could be wrong) that this would speed up calculations because they square root faster than a value say 13.3827999
Another random to reduce is scale, usually a tree drops in with a big floaty 1.12345, the next one at 1.111342, no tree is the same size,
I recon pick 4, 8… or 16 different size scales to use.
But not just any scale, a neat scale that fits with power 2
build a size using numbers like 0.5 0.25 0.125 0.0625 0.03125 (half the previous)
so say, use scale 1 + 0.125 - 0.03125 = 1.09375
the magic when you multiply 1.09375 x 512 is it equals 560… multiply any of these numbers by 512 to get a whole number
maybe it saves some CPU/GPU time… ???
And rotations, put lots at 0,0,0 use negative L and/or R scale on some of these
limit rotations in general to 15, 30, 45 etc
@Hardcawcanary I don’t think there is any benefit to rounding off floats and using power of 2 scaling. Under the hood all the values will still be a (32bit?) floating point number (as opposed to an integer)
Tangential, but in the context of mobile there is a ‘Float Precision Mode’ inside of Materials - so that’s just an example of an optimization happening automatically on mobile architecture. (Also the ‘fluid/shaking’ look from Playstation 1 is something to look at when going down the floating point precision rabbit hole)
How to optimize for mobile is a really good question though. Using referenced assets throws another wrench into it. (Hopefully they have a reasonably good LOD setup?) - If you had control over the materials, simplifying them for mobile with a Quality Switch could be something to try.
I’d do some tests in a new map to verify that it’s really the trees causing issues. (In my experience shadows can be a big performance hog, so consider experimenting with lighting setup as well) Shadows should be disabled when mobile graphics settings are set to ‘low’ though.
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@Astrotronic, thank you for the voice of reason, some poor creator goes in and manually edits 500 tree transforms… for no benefit… ahem…