Fresnel Equations

Computer Graphics · Materials and BSDFs · fresnel.yaml

Give the fraction of light reflected rather than transmitted at an interface, as a function of angle and the two indices of refraction. Reflectance rises to one at grazing incidence for every material.

• supersedescorrects · extends
• classifiesspecializes · part-of
• substitutes forapproximates · alternative-to
• depends onrequires · validates

Colour is the family; a dashed line is the second member of it.

This node

• part-ofis a subtopic of Reflection
• requiresdoes not work without Refractionthe split between the two is what it computes

Referenced by

• correctsArtist-Friendly Metallic Fresnel fixes a defect in thisreflectivity and edge tint, not unauthorable complex IOR
• requiresMicrofacet Model does not work without thiseach microfacet is a mirror, so needs its reflectance
• approximatesSchlick's Approximation is a cheaper stand-in for thisa fifth-power curve instead of the full equations
• extendsThin-Film Iridescence adds capability to thisinterference in a thin coat makes reflectance shift

References

• Fresnel equations (lecture notes) · link
• Background — Fresnel equations on Wikipedia