Portal Edge Shaders

What this builds

The boundary treatment that turns a correct portal into a convincing one. A portal rendered with perfect camera math and a hard rectangular edge still reads as a texture on a plane. The edge is what carries the fiction.

• Fresnel rim that brightens at grazing angles, the single highest-value effect
• Noise dissolve so the opening has an irregular, non-manufactured boundary
• Tear and unzip openings for portals that appear
• Chromatic fringing at the boundary
• Refraction skirt so the world bends slightly at the rim
• Energy ring with controllable turbulence
• Opening and closing animations driven by one uniform

All of these are additive over an existing portal surface, whether it is a stencil mask, a render target sample, or a DOM mask.