Packing 2 uv's in a float4?

I tried this (via a custom vertex shader), but ShaderLab is throwing errors (see attached). Is doing this a no-no? Is someone else doing it?

Can’t see your attachment for some reason.

But I’ve packed 2 UVs into a float4 in the past just fine, don’t see any reason it wouldn’t work.

How about you post your code (as text, attachments appear to be broken)?

It works fine but I never do it because it’s not performant on the GPUs I care about.

Why is that?

If I understand it correctly…

On mobile devices, it apparently counts as a dependent texture fetch because you have to use swizzling to pull out the UVs again. Meaning it won’t fetch the texture until it hits that bit in the fragment shader.

If you feed in the raw vertex shader values, it can pre-fetch the texture data and that’ll wind up more efficient than saving an interpolator.

Got it - I called the parameter “uv”. Renamed to “pants” and it stopped whining. Why didn’t it bloody say so!