Refraction Model Specifies the model HDRP uses to process refraction. The options are:
• None: No refraction occurs. Select this option to disable refraction.
• Box: A box-shaped model where incident light enters through a flat surface and leaves through a flat surface. Select this option for hollow surfaces.
• Sphere: A sphere-shaped model that produces a magnifying glass-like effect to refraction. Select this option for solid surfaces.
• Thin: A thin box surface type, equivalent to Box with a fixed thickness of 5cm. Select this for thin window-like surfaces.