Edge

Refraction is strongest at the boundary and decays to zero over width.

Rounded corners use an optical radius 1.5 times the visible radius, capped at half the material's shortest side. Displacement is also capped at half that side. SurfaceProfile and GlassOptics.refractionHeightFraction continue to control lighting, independently of refraction.

width must be specified, finite, and non-negative. A zero width disables refraction, including its secondary detail pass. Simplified renderers may omit refraction entirely.