1 /*
2 * Adapted from Open Shading Language with this license:
3 *
4 * Copyright (c) 2009-2010 Sony Pictures Imageworks Inc., et al.
5 * All Rights Reserved.
6 *
7 * Modifications Copyright 2011, Blender Foundation.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions are
11 * met:
12 * * Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 * * Redistributions in binary form must reproduce the above copyright
15 * notice, this list of conditions and the following disclaimer in the
16 * documentation and/or other materials provided with the distribution.
17 * * Neither the name of Sony Pictures Imageworks nor the names of its
18 * contributors may be used to endorse or promote products derived from
19 * this software without specific prior written permission.
20 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
21 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
22 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
23 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
24 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
25 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
26 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
27 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
28 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
29 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
30 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
31 */
32
33 #ifndef __BSDF_TRANSPARENT_H__
34 #define __BSDF_TRANSPARENT_H__
35
36 CCL_NAMESPACE_BEGIN
37
bsdf_transparent_setup(ShaderData * sd,const float3 weight,int path_flag)38 ccl_device void bsdf_transparent_setup(ShaderData *sd, const float3 weight, int path_flag)
39 {
40 /* Check cutoff weight. */
41 float sample_weight = fabsf(average(weight));
42 if (!(sample_weight >= CLOSURE_WEIGHT_CUTOFF)) {
43 return;
44 }
45
46 if (sd->flag & SD_TRANSPARENT) {
47 sd->closure_transparent_extinction += weight;
48
49 /* Add weight to existing transparent BSDF. */
50 for (int i = 0; i < sd->num_closure; i++) {
51 ShaderClosure *sc = &sd->closure[i];
52
53 if (sc->type == CLOSURE_BSDF_TRANSPARENT_ID) {
54 sc->weight += weight;
55 sc->sample_weight += sample_weight;
56 break;
57 }
58 }
59 }
60 else {
61 sd->flag |= SD_BSDF | SD_TRANSPARENT;
62 sd->closure_transparent_extinction = weight;
63
64 if (path_flag & PATH_RAY_TERMINATE) {
65 /* In this case the number of closures is set to zero to disable
66 * all others, but we still want to get transparency so increase
67 * the number just for this. */
68 sd->num_closure_left = 1;
69 }
70
71 /* Create new transparent BSDF. */
72 ShaderClosure *bsdf = closure_alloc(
73 sd, sizeof(ShaderClosure), CLOSURE_BSDF_TRANSPARENT_ID, weight);
74
75 if (bsdf) {
76 bsdf->sample_weight = sample_weight;
77 bsdf->N = sd->N;
78 }
79 else if (path_flag & PATH_RAY_TERMINATE) {
80 sd->num_closure_left = 0;
81 }
82 }
83 }
84
bsdf_transparent_eval_reflect(const ShaderClosure * sc,const float3 I,const float3 omega_in,float * pdf)85 ccl_device float3 bsdf_transparent_eval_reflect(const ShaderClosure *sc,
86 const float3 I,
87 const float3 omega_in,
88 float *pdf)
89 {
90 return make_float3(0.0f, 0.0f, 0.0f);
91 }
92
bsdf_transparent_eval_transmit(const ShaderClosure * sc,const float3 I,const float3 omega_in,float * pdf)93 ccl_device float3 bsdf_transparent_eval_transmit(const ShaderClosure *sc,
94 const float3 I,
95 const float3 omega_in,
96 float *pdf)
97 {
98 return make_float3(0.0f, 0.0f, 0.0f);
99 }
100
bsdf_transparent_sample(const ShaderClosure * sc,float3 Ng,float3 I,float3 dIdx,float3 dIdy,float randu,float randv,float3 * eval,float3 * omega_in,float3 * domega_in_dx,float3 * domega_in_dy,float * pdf)101 ccl_device int bsdf_transparent_sample(const ShaderClosure *sc,
102 float3 Ng,
103 float3 I,
104 float3 dIdx,
105 float3 dIdy,
106 float randu,
107 float randv,
108 float3 *eval,
109 float3 *omega_in,
110 float3 *domega_in_dx,
111 float3 *domega_in_dy,
112 float *pdf)
113 {
114 // only one direction is possible
115 *omega_in = -I;
116 #ifdef __RAY_DIFFERENTIALS__
117 *domega_in_dx = -dIdx;
118 *domega_in_dy = -dIdy;
119 #endif
120 *pdf = 1;
121 *eval = make_float3(1, 1, 1);
122 return LABEL_TRANSMIT | LABEL_TRANSPARENT;
123 }
124
125 CCL_NAMESPACE_END
126
127 #endif /* __BSDF_TRANSPARENT_H__ */
128