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/*
* Copyright 2011-2014 Blender Foundation
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License
*/
color fresnel_conductor(float cosi, color eta, color k)
{
color cosi2 = color(cosi * cosi);
color one = color(1, 1, 1);
color tmp_f = eta * eta + k * k;
color tmp = tmp_f * cosi2;
color Rparl2 = (tmp - (2.0 * eta * cosi) + one) /
(tmp + (2.0 * eta * cosi) + one);
color Rperp2 = (tmp_f - (2.0 * eta * cosi) + cosi2) /
(tmp_f + (2.0 * eta * cosi) + cosi2);
return (Rparl2 + Rperp2) * 0.5;
}
shader node_fresnel_conductive(
color n = color(0.084136, 0.410708, 1.472421),
color k = color(4.018579, 2.363371, 1.607574),
normal Normal = N,
output color Color = color(0.8, 0.8, 0.8))
{
float cosi = dot(I, Normal);
Color = fresnel_conductor(cosi, n, k);
}
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