Consider a Metal-based fallback for glassEffect instead of ultraThinMaterial?

[videni]

The Problem:

The current fallback for .backport.glassEffect() on iOS 17/18 uses .ultraThinMaterial, but the visual result is quite far from the iOS 26 Liquid Glass aesthetic. The material-based approach lacks:

• Refraction/distortion effects
• Depth-aware reflections
• The "liquid" feel of the glass

This creates a noticeable visual gap between iOS versions.

Suggestion:

Would you consider using a Metal shader-based approach for the fallback? There's a library called GlassEffect that implements GPU-rendered glass effects with:

• Real refraction and reflection simulation
• Fresnel effect
• Normal map texture support
• iOS 17+ compatibility

This could provide a much closer approximation to iOS 26's Liquid Glass on older devices, offering a more consistent cross-version experience.

Would you be open to exploring this as an alternative fallback implementation?

Thank you!

[danjford]

I don't really have any sway on this, but I think there could be a possible solution without adding dependencies to this lib (if it works).

Maybe there could be an optional overload which would allow calling code to glassEffect() to provide how it wants it to behave instead of ultraThinMaterial.

When I next have time I'll see if I can test and write a PR using GlassEffect as an example.

In terms of expected functionality, I would have thought iOS 17/18 users would expect something more like ultraThinMaterial then a Liquid Glass effect but that's just a personal opinion