HDRP with iOS support

Unity Engine
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1

Any chance we can experiment with HDRP on recent iOS devices anytime soon?

I thought HDRP was “supported” on high-end iOS devices which support compute shaders? I know HDRP is a beast, but I do believe there are use cases for iOS support.

-Thanks

2

Hi,

We have no plan for now to add the support to IOS.

If you want to experiment with it, you can uncomment this line here:

If you uncomment it then you will be allowed to build on IOS.

However we don’t offer any support in this case. We are aware of few projects with a customize hdrp that are able to run on ipad pro, so we know there is thing working. We mainly don’t officially support IOS because we don’t have the performance. We haven’t done any mobile specific optimization for hdrp (it is even the opposite, we rely on async compute and are doing a lot of “resolve” which are counter productive on gpu tiled archtiecture, we don’t have simplified ligthing code) thus it will run around 5 fps which is useless.

You could of course remove various features, optimize various code etc… And depends on your need you could achieve something. Also we have check it for a while, HDRP run on metal correctly, but if something differ on ios, it is possible that some featuers don’t work at all.

3

I just got the iPhone 15 Pro and am curious if the limitation still applies to such a capable device? We have a URP branch anyway, but since the HDRP version runs at 60 FPS most of the time on a Steam Deck, I’m under the impression the new iPhone could handle it… But maybe not as you mentioned the gpu tiled architecture thingy.

4

Hi I was also interested in testing HDRP on a M2 iOS iPad device. In the past when I wanted to make changes to a Unity package, I copied the package from Library/PackageCache/ to the Packages folder. when i do this with the HDRP package on Unity 2022.3.10 the editor always crashes once the project is opened. How does one make the mods persistent these days?

5

Curious if this has been resolved by now. I run HDRP fine (and with good performance) on an M3 Max Mac chip, curious if it could also run on an M2 iOS (iPad).

6

Hi, The answer is still the same than previously HDRP with iOS support .
With a small addition: We have done some extra fix on IOS after an experiment (in volumetric and APV mostly), and the new STP upscaler can work on IOS, and thus if you use it, it will allow to run HDRP more smoothly on mobile.

But you are on your own here, no official support.

7

But out of curiosity, why does it run well on Apple Silicon? And why wouldn’t an iPad Air M1 work as well?

8

Regarding device like IPad Air M1 that have enough performance to run HDRP, we can still have various artifacts given we haven’t tested it - this often appear in code like volumetric fog that are qui demanding/complex. We don’t have time to investigate those, but we also don’t have way in Unity to enable HDRP only for the specific case of the “IPad Air M1”, if we enable IOS build, it cover a lot of different platform

9

It is not just a “specific case”, all iPad Air and Pro models have an Apple Silicon chips on board now.

10

Actually, Apple offers a handy solution for that. See the developer video:
https://developer.apple.com/videos/play/tech-talks/111372/?time=310

You can make that with HDRP and a iOS target this flag is always set when a Xcode project is created from Unity. We also want HDRP on iOS and in general performance improvements for Apple Silicon chips on macOS for both editor and builds. The whole SRP coexistence strategy is awful and not interesting to us.

11

You could try this package to enable the build on mobile platforms: GitHub - alelievr/HDRP-Mobile: Unlock HDRP to build on mobile devices though you’ll likely experience issues as it’s not officially supported and tested by Unity.

12

After seeing news that Unity is working on portable console support for HDRP, I thought: why not try iOS? Newer devices have quite a bit of performance, so it seemed worth experimenting.

My goal was to get the scene running on an iPhone 16 Pro with as few visual compromises as possible compared to the PC version. Honestly, I had zero expectations, especially since my scene is very demanding. The original target hardware was an RTX 4090 with photorealistic look.

Scene parameters
• Geometry: 32 million polys (up to ~10 million visible in camera view)
• Lighting: only Adaptive Probe Volumes (~2.5M probes generated, 160 cell count, memory budget set to High)
• Effects: Post-processing enabled (bloom, tonemapping, etc.)
• GI/AO: Ray Marching + GTAO (htrace)
• Lights: 43 realtime lights with shadows + 22 realtime lights without shadows, other was baked
• Scaling: STP with forced percentage at 60%
• Environment: Dense foliage — trees, grass, bushes, decorative flowers, fountain particles etc.

Overall, it’s a very heavy scene.

At first, I tried Unity 6.3b2 and 6.2, but I consistently ran into build issues in Xcode:

“command phasescriptexecution failed with a nonzero exit code”

I attempted every fix I could find online, but nothing worked. Eventually, I downgraded the project to Unity 6.0.33 (where I had previously built iOS projects with URP).

To my surprise, the scene actually runs — and pretty smoothly! On the iPhone 16 Pro, I’m getting 30–70 FPS depending on the view. Even at 60% STP scaling, the visuals still look excellent.

I’m genuinely impressed that HDRP can now run on iOS, even if it’s not officially supported yet. It’s a shame there’s no official support, but the fact that it works at all is really exciting.