blob: f583df2577396bbcab9fd881a101ed2795127151 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
|
/*
* Copyright 2011-2013 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.
*/
#include "stdosl.h"
#include "node_fresnel.h"
shader node_layer_weight(
float Blend = 0.5,
normal Normal = N,
output float Fresnel = 0.0,
output float Facing = 0.0)
{
float blend = Blend;
float cosi = dot(I, Normal);
/* Fresnel */
float eta = max(1.0 - Blend, 1e-5);
eta = backfacing() ? eta : 1.0 / eta;
Fresnel = fresnel_dielectric_cos(cosi, eta);
/* Facing */
Facing = fabs(cosi);
if (blend != 0.5) {
blend = clamp(blend, 0.0, 1.0 - 1e-5);
blend = (blend < 0.5) ? 2.0 * blend : 0.5 / (1.0 - blend);
Facing = pow(Facing, blend);
}
Facing = 1.0 - Facing;
}
|
