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Examples
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refract

calculate the refraction direction for an incident vector

Declaration

  • float refract(float I, float N, float eta)
  • vec2 refract(vec2 I, vec2 N, float eta)
  • vec3 refract(vec3 I, vec3 N, float eta)
  • vec4 refract(vec4 I, vec4 N, float eta)

Parameters

  • I: Specifies the incident vector.
  • N: Specifies the normal vector.
  • eta: Specifies the ratio of indices of refraction.

Description

For a given incident vector I, surface normal N and ratio of indices of refraction, eta, refract returns the refraction vector, R. R is calculated as:

k = 1.0 - eta * eta * (1.0 - dot(N, I) * dot(N, I)); if (k < 0.0) R = genType(0.0); // or genDType(0.0) else R = eta * I - (eta * dot(N, I) + sqrt(k)) * N;

The input parameters I and N should be normalized in order to achieve the desired result.

See Also

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