33 lines
777 B
Plaintext
33 lines
777 B
Plaintext
/* SPDX-FileCopyrightText: 2011-2022 Blender Foundation
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*
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* SPDX-License-Identifier: Apache-2.0 */
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#include "node_fresnel.h"
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#include "stdcycles.h"
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shader node_layer_weight(float Blend = 0.5,
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normal Normal = N,
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output float Fresnel = 0.0,
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output float Facing = 0.0)
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{
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float blend = Blend;
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float cosi = dot(I, Normal);
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/* Fresnel */
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float eta = max(1.0 - Blend, 1e-5);
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eta = backfacing() ? eta : 1.0 / eta;
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Fresnel = fresnel_dielectric_cos(cosi, eta);
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/* Facing */
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Facing = fabs(cosi);
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if (blend != 0.5) {
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blend = clamp(blend, 0.0, 1.0 - 1e-5);
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blend = (blend < 0.5) ? 2.0 * blend : 0.5 / (1.0 - blend);
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Facing = pow(Facing, blend);
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}
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Facing = 1.0 - Facing;
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}
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