Long shader compilation time for Android

[spirosperos]

Hello! I'm working on a project involving a Quest 3s (Android) device and Unity. I am currently trying to load a .glb file and visualize it in VR. I'm facing a problem regarding missing shaders, which should be possible to solve by adding UnityGLTF/PBRGraph to the list of always included shaders. However, when I do this I get the following error:

Error building Player: UnityGLTF/PBRGraph has too many Shader variants (1179648)

After taking a look at the issues, I've found this comment saying that I should try preloading the predefined shader variant collection. This leads to a huge compilation time, due to a big number of variants.

Is there anything I could do to speed this process up? I'm building using Unity 2022.3.8f1

[hybridherbst]

Hey, couple questions:

• Which UnityGLTF version are you using?
• Are you using URP or BiRP?
• Are you using any specific renderer features in your URP asset?
• Did you remove the shader from the "always included shaders" list after adding the premade variant sets?

With the included variant collections this should not happen. Generally, if you want to load any type of GLTF at runtime (as you typically want), then there are relatively large number of shaders to include, but not as many as visible in your screenshot.

[palhimanshu1991]

@hybridherbst i'm facing similar issues at importing asset at runtime.

I've installed the UnityGLTF 2.14.1 version via github URL in Unity version 6.0.
I'm using URP, im using a mostly blank project and added the shader graph in the "always included shaders" list as suggested,
but the build on Macbook M1 chip is taking forever.
Is this expected?

[atkulp]

This is what worked for me. Don't add it to Always Included, add the variant collection to Preloaded Shaders. Just match the variant collection to the pipeline setting.

[hybridherbst]

Yes, using the provided Shader Variant Collections is the suggested resolution here. Adding to "Always included" will cause Unity to compile a giant amount of unnecessary variants, which they told me is "by design" unfortunately.

Please use the Variant Collection! And if that doesn't work, please open a new issue.