How we hit 60 FPS on mid-range Android porting a 300GB Unreal PC project.

DLSS and FSR don't exist on Android. Audit plugins on day zero.

The PC build had both. DLSS for Nvidia, FSR for AMD. Neither exists on mobile. Not "limited support." They literally do not exist on Android and the plugins won't cook.

We spent day one trying to just disable them, then realised the render pipeline had nodes wired through both. You have to actually rip them out. We replaced both with TAAU. Tried TSR first since it's the new approach but mobile support there isn't ready yet. We landed on lower internal resolution plus TAAU upscale, which gave the best perf-to-quality on mid-range.

Lumen and Nanite don't ship on mobile. Get art involved in week one.

Same deal as the upscalers. Neither works on Android. The original team built the lighting around Lumen because of course they did, why wouldn't you on PC. Rebaking the lighting was the single biggest art-side lift in the whole port.

We baked lightmaps for every static piece of hub geo. Capped dynamic shadow casters at one or two per view. Mobile GPUs absolutely will not do more. Distance-based shadow fading on everything else. Then leaned hard on emissive materials to keep the heavy-metal underground vibe alive.

Took maybe three weeks of art-engineer ping pong before it stopped looking flat. The lesson: engineers cannot bake lighting that preserves art direction. It can't be done. Get the art lead in from week one or you'll redo it.

For Nanite we just fell back to standard LOD chains. Source meshes were clean so regenerating LODs was mostly automatic. Materials on those meshes were the actual problem.

FIG 01 / Lighting rebake comparisonHub Zone 03

Deferred to Mobile Forward+ is project-wide. Don't half-commit.

The PC build was deferred. Mobile needs Mobile Forward or Forward+. This isn't a setting you flip. It's a project-wide config change that breaks things you forgot you were using. SSAO, SSR, SSGI, all your screen-space stuff. Either dies or becomes way too expensive. We rewrote post-process volumes per zone, around 40 of them across the project.

Forward+ on mobile in UE5 is actually fine if you commit to it. The trap is trying to keep half your deferred effects working alongside it, which is exactly what we did for a week before someone said okay we have to just do this properly. Free week of your life if you skip our mistake here.

Materials. This is where the actual time went.

I cannot stress this enough.

Mobile shader cores have hard instruction limits. A "looks fine" PC material can run 200+ instructions because nothing matters on a 4090. On a Snapdragon 778G it's a slideshow. Not a slowdown. An actual slideshow.

Every hero material got rebuilt using UE's Mobile Material framework. Multi-layer materials, pixel-depth offsets, parallax, advanced translucency. Gone. Replaced. Material LODs got added everywhere (yes that's a real thing, no most people don't use them) so distant assets dropped to roughly 30-instruction versions.

The thing that actually saved us hours

Preview materials in ES3.1 and Vulkan shader preview modes inside UE before you cook. UE will happily let you ship a material that compiles on PC and then silently breaks on Android. Catching it in the editor is way faster than "okay why is the wall pink on this Pixel 6 specifically."

Texture budgets that respect device tier, not PC defaults.

Original textures were sized for PC VRAM, which is to say, generously. We capped hero stuff at 2048, most other things at 1024. ASTC for the Vulkan path, ETC2 fallback for OpenGL ES 3.2.

Streaming pool budgets got set up to actually respect device tier instead of using PC defaults. Dungeon zones were the worst because environmental storytelling means tons of unique props. We replaced a bunch of unique meshes with instanced versions on shared atlased materials. Visual difference basically nothing. Draw calls dropped hard.

FIG 02 / Texture pipelineASTC / ETC2

The 300GB problem and how Play Asset Delivery solved it.

The project being 300GB on disk doesn't mean the APK is 300GB. Most of that is source files, intermediates, and plugin source. But the cooked Android content was still way past Google's 150MB base APK limit.

Play Asset Delivery handled it. We split into three buckets:

Install-time

Core hub, one starter zone, essential UI and audio. Ships with the install.

Fast-follow

Remaining hub zones, downloaded right after install completes.

On-demand

Individual portal zones, fetched the first time a player unlocks them.

This is more engineering than people expect. In-game download manager UI, retry logic, storage warnings, mobile-data warnings. Test it on actually flaky 4G, not on dev wifi, or you'll find out at launch what real users experience.

Touch input is a rewrite, not an adaptation.

Tab key, F key, keyboard mappings, none of that translates. We built it fresh with Enhanced Input System and touch mappings. Virtual joystick on the left thumb, camera on the right, action buttons sized to Android's 48dp accessibility minimum.

The emote system (air guitar, air drums, on-brand for a music metaverse) was actually the fun part. Radial emote wheel off a HUD button. We tested multiplayer sync between PC and Android clients in the same session and it worked first try, which never happens.

Thermal throttling is the silent killer. Test for 20 minutes, not 5.

You'll hit 60 FPS for 5 minutes on a Snapdragon 778G and think you've won. Then the device thermally throttles and your frame rate quietly tanks. If you're testing in 5-minute bursts, you are testing the wrong thing.

We added dynamic resolution scaling as a thermal fallback. When sustained-load profiling sees thermal events coming, the engine drops internal resolution before it drops frames. Players notice slightly softer image, not stutter. That tradeoff plays way better in user testing than the alternative.

FIG 03 / QA thermal rigFriday Sustained Load

What it actually runs at.

People always ask for the numbers. Here they are.

The 60 FPS on high tier is the headline number. Honestly the harder win was making the 30 FPS feel rock solid on the mid-range. Locked 30 with zero spikes feels better than an inconsistent 50. Anyone who's played a phone game that surges to 55 then drops to 28 every minute knows what I mean.

Things we wish someone had told us on day one.