Very nice, I approve of anything that goes against the Material Design hegemony.
One question though: there's a (relatively) large delay updating the demo when I change the convexity. Is this something that comes from the update script or is the effect itself slow? Because I don't think I've ever seen a CSS effect that takes a half second to update before.
I checked out the source, there's only a single canvas being used to render a base64 PNG. The PNG is just a 400x400 spherical reflection map, which is basically a required component of any metallic effect. I don't think that would cause a slowdown.
One question though: there's a (relatively) large delay updating the demo when I change the convexity. Is this something that comes from the update script or is the effect itself slow? Because I don't think I've ever seen a CSS effect that takes a half second to update before.