1 |
greg |
1.1 |
#ifndef lint |
2 |
greg |
2.38 |
static const char RCSid[] = "$Id$"; |
3 |
greg |
1.1 |
#endif |
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/* |
5 |
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* normal.c - shading function for normal materials. |
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* |
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* 8/19/85 |
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* 12/19/85 - added stuff for metals. |
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* 6/26/87 - improved specular model. |
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* 9/28/87 - added model for translucent materials. |
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greg |
2.2 |
* Later changes described in delta comments. |
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greg |
1.1 |
*/ |
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greg |
2.38 |
/* ==================================================================== |
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* The Radiance Software License, Version 1.0 |
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* |
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* Copyright (c) 1990 - 2002 The Regents of the University of California, |
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* through Lawrence Berkeley National Laboratory. All rights reserved. |
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* |
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* Redistribution and use in source and binary forms, with or without |
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* modification, are permitted provided that the following conditions |
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* are met: |
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* |
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* 1. Redistributions of source code must retain the above copyright |
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* notice, this list of conditions and the following disclaimer. |
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* |
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* 2. Redistributions in binary form must reproduce the above copyright |
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* notice, this list of conditions and the following disclaimer in |
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* the documentation and/or other materials provided with the |
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* distribution. |
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* |
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* 3. The end-user documentation included with the redistribution, |
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* if any, must include the following acknowledgment: |
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* "This product includes Radiance software |
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* (http://radsite.lbl.gov/) |
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* developed by the Lawrence Berkeley National Laboratory |
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* (http://www.lbl.gov/)." |
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* Alternately, this acknowledgment may appear in the software itself, |
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* if and wherever such third-party acknowledgments normally appear. |
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* |
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* 4. The names "Radiance," "Lawrence Berkeley National Laboratory" |
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* and "The Regents of the University of California" must |
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* not be used to endorse or promote products derived from this |
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* software without prior written permission. For written |
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* permission, please contact [email protected]. |
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* |
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* 5. Products derived from this software may not be called "Radiance", |
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* nor may "Radiance" appear in their name, without prior written |
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* permission of Lawrence Berkeley National Laboratory. |
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* |
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* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED |
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* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
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* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE |
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* DISCLAIMED. IN NO EVENT SHALL Lawrence Berkeley National Laboratory OR |
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* ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
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* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
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* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF |
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* USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND |
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* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, |
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* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT |
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* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
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* SUCH DAMAGE. |
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* ==================================================================== |
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* |
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* This software consists of voluntary contributions made by many |
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* individuals on behalf of Lawrence Berkeley National Laboratory. For more |
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* information on Lawrence Berkeley National Laboratory, please see |
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* <http://www.lbl.gov/>. |
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*/ |
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greg |
1.1 |
#include "ray.h" |
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#include "otypes.h" |
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75 |
greg |
2.2 |
#include "random.h" |
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77 |
greg |
2.34 |
#ifndef MAXITER |
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#define MAXITER 10 /* maximum # specular ray attempts */ |
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#endif |
80 |
greg |
2.38 |
/* estimate of Fresnel function */ |
81 |
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#define FRESNE(ci) (exp(-6.0*(ci)) - 0.00247875217) |
82 |
greg |
2.34 |
|
83 |
greg |
2.38 |
static void gaussamp(); |
84 |
greg |
2.24 |
|
85 |
greg |
1.1 |
/* |
86 |
greg |
2.22 |
* This routine implements the isotropic Gaussian |
87 |
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* model described by Ward in Siggraph `92 article. |
88 |
greg |
1.1 |
* We orient the surface towards the incoming ray, so a single |
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* surface can be used to represent an infinitely thin object. |
90 |
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* |
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* Arguments for MAT_PLASTIC and MAT_METAL are: |
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* red grn blu specular-frac. facet-slope |
93 |
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* |
94 |
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* Arguments for MAT_TRANS are: |
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* red grn blu rspec rough trans tspec |
96 |
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*/ |
97 |
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98 |
greg |
2.2 |
/* specularity flags */ |
99 |
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#define SP_REFL 01 /* has reflected specular component */ |
100 |
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#define SP_TRAN 02 /* has transmitted specular */ |
101 |
greg |
2.11 |
#define SP_PURE 04 /* purely specular (zero roughness) */ |
102 |
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#define SP_FLAT 010 /* flat reflecting surface */ |
103 |
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#define SP_RBLT 020 /* reflection below sample threshold */ |
104 |
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#define SP_TBLT 040 /* transmission below threshold */ |
105 |
greg |
1.1 |
|
106 |
greg |
1.3 |
typedef struct { |
107 |
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OBJREC *mp; /* material pointer */ |
108 |
greg |
2.16 |
RAY *rp; /* ray pointer */ |
109 |
greg |
2.2 |
short specfl; /* specularity flags, defined above */ |
110 |
greg |
1.1 |
COLOR mcolor; /* color of this material */ |
111 |
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COLOR scolor; /* color of specular component */ |
112 |
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FVECT vrefl; /* vector in direction of reflected ray */ |
113 |
greg |
1.14 |
FVECT prdir; /* vector in transmitted direction */ |
114 |
greg |
2.2 |
double alpha2; /* roughness squared */ |
115 |
greg |
1.1 |
double rdiff, rspec; /* reflected specular, diffuse */ |
116 |
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double trans; /* transmissivity */ |
117 |
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double tdiff, tspec; /* transmitted specular, diffuse */ |
118 |
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FVECT pnorm; /* perturbed surface normal */ |
119 |
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double pdot; /* perturbed dot product */ |
120 |
greg |
1.3 |
} NORMDAT; /* normal material data */ |
121 |
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122 |
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123 |
greg |
2.38 |
static void |
124 |
greg |
1.3 |
dirnorm(cval, np, ldir, omega) /* compute source contribution */ |
125 |
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COLOR cval; /* returned coefficient */ |
126 |
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register NORMDAT *np; /* material data */ |
127 |
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FVECT ldir; /* light source direction */ |
128 |
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double omega; /* light source size */ |
129 |
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{ |
130 |
greg |
1.1 |
double ldot; |
131 |
greg |
2.38 |
double ldiff; |
132 |
greg |
2.16 |
double dtmp, d2; |
133 |
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FVECT vtmp; |
134 |
greg |
1.3 |
COLOR ctmp; |
135 |
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136 |
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setcolor(cval, 0.0, 0.0, 0.0); |
137 |
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138 |
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ldot = DOT(np->pnorm, ldir); |
139 |
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140 |
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if (ldot < 0.0 ? np->trans <= FTINY : np->trans >= 1.0-FTINY) |
141 |
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return; /* wrong side */ |
142 |
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143 |
greg |
2.38 |
/* Fresnel estimate */ |
144 |
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ldiff = np->rdiff; |
145 |
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if (np->specfl & SP_PURE && (np->rspec > FTINY & ldiff > FTINY)) |
146 |
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ldiff *= 1. - FRESNE(fabs(ldot)); |
147 |
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148 |
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if (ldot > FTINY && ldiff > FTINY) { |
149 |
greg |
1.3 |
/* |
150 |
greg |
1.4 |
* Compute and add diffuse reflected component to returned |
151 |
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* color. The diffuse reflected component will always be |
152 |
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* modified by the color of the material. |
153 |
greg |
1.3 |
*/ |
154 |
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copycolor(ctmp, np->mcolor); |
155 |
greg |
2.38 |
dtmp = ldot * omega * ldiff / PI; |
156 |
greg |
1.3 |
scalecolor(ctmp, dtmp); |
157 |
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addcolor(cval, ctmp); |
158 |
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} |
159 |
greg |
2.2 |
if (ldot > FTINY && (np->specfl&(SP_REFL|SP_PURE)) == SP_REFL) { |
160 |
greg |
1.3 |
/* |
161 |
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* Compute specular reflection coefficient using |
162 |
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* gaussian distribution model. |
163 |
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*/ |
164 |
greg |
2.3 |
/* roughness */ |
165 |
greg |
2.16 |
dtmp = np->alpha2; |
166 |
greg |
2.3 |
/* + source if flat */ |
167 |
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if (np->specfl & SP_FLAT) |
168 |
greg |
2.16 |
dtmp += omega/(4.0*PI); |
169 |
greg |
2.23 |
/* half vector */ |
170 |
greg |
2.18 |
vtmp[0] = ldir[0] - np->rp->rdir[0]; |
171 |
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vtmp[1] = ldir[1] - np->rp->rdir[1]; |
172 |
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vtmp[2] = ldir[2] - np->rp->rdir[2]; |
173 |
greg |
2.16 |
d2 = DOT(vtmp, np->pnorm); |
174 |
greg |
2.23 |
d2 *= d2; |
175 |
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d2 = (DOT(vtmp,vtmp) - d2) / d2; |
176 |
greg |
1.3 |
/* gaussian */ |
177 |
greg |
2.16 |
dtmp = exp(-d2/dtmp)/(4.*PI*dtmp); |
178 |
greg |
1.3 |
/* worth using? */ |
179 |
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if (dtmp > FTINY) { |
180 |
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copycolor(ctmp, np->scolor); |
181 |
greg |
2.14 |
dtmp *= omega * sqrt(ldot/np->pdot); |
182 |
greg |
1.3 |
scalecolor(ctmp, dtmp); |
183 |
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addcolor(cval, ctmp); |
184 |
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} |
185 |
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} |
186 |
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if (ldot < -FTINY && np->tdiff > FTINY) { |
187 |
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/* |
188 |
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* Compute diffuse transmission. |
189 |
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*/ |
190 |
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copycolor(ctmp, np->mcolor); |
191 |
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dtmp = -ldot * omega * np->tdiff / PI; |
192 |
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scalecolor(ctmp, dtmp); |
193 |
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addcolor(cval, ctmp); |
194 |
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} |
195 |
greg |
2.2 |
if (ldot < -FTINY && (np->specfl&(SP_TRAN|SP_PURE)) == SP_TRAN) { |
196 |
greg |
1.3 |
/* |
197 |
greg |
1.4 |
* Compute specular transmission. Specular transmission |
198 |
greg |
1.13 |
* is always modified by material color. |
199 |
greg |
1.3 |
*/ |
200 |
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/* roughness + source */ |
201 |
greg |
2.19 |
dtmp = np->alpha2 + omega/PI; |
202 |
greg |
1.3 |
/* gaussian */ |
203 |
greg |
2.21 |
dtmp = exp((2.*DOT(np->prdir,ldir)-2.)/dtmp)/(PI*dtmp); |
204 |
greg |
1.3 |
/* worth using? */ |
205 |
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if (dtmp > FTINY) { |
206 |
greg |
1.13 |
copycolor(ctmp, np->mcolor); |
207 |
greg |
2.18 |
dtmp *= np->tspec * omega * sqrt(-ldot/np->pdot); |
208 |
greg |
1.13 |
scalecolor(ctmp, dtmp); |
209 |
greg |
1.3 |
addcolor(cval, ctmp); |
210 |
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} |
211 |
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} |
212 |
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} |
213 |
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214 |
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215 |
greg |
2.38 |
int |
216 |
greg |
2.2 |
m_normal(m, r) /* color a ray that hit something normal */ |
217 |
greg |
1.3 |
register OBJREC *m; |
218 |
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register RAY *r; |
219 |
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{ |
220 |
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NORMDAT nd; |
221 |
greg |
2.38 |
double fest; |
222 |
greg |
1.9 |
double transtest, transdist; |
223 |
greg |
2.29 |
double mirtest, mirdist; |
224 |
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int hastexture; |
225 |
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double d; |
226 |
greg |
1.1 |
COLOR ctmp; |
227 |
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register int i; |
228 |
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/* easy shadow test */ |
229 |
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if (r->crtype & SHADOW && m->otype != MAT_TRANS) |
230 |
greg |
2.27 |
return(1); |
231 |
greg |
2.2 |
|
232 |
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if (m->oargs.nfargs != (m->otype == MAT_TRANS ? 7 : 5)) |
233 |
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objerror(m, USER, "bad number of arguments"); |
234 |
greg |
2.29 |
/* check for back side */ |
235 |
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if (r->rod < 0.0) { |
236 |
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if (!backvis && m->otype != MAT_TRANS) { |
237 |
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raytrans(r); |
238 |
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return(1); |
239 |
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} |
240 |
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flipsurface(r); /* reorient if backvis */ |
241 |
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} |
242 |
greg |
1.3 |
nd.mp = m; |
243 |
greg |
2.16 |
nd.rp = r; |
244 |
greg |
1.1 |
/* get material color */ |
245 |
greg |
1.3 |
setcolor(nd.mcolor, m->oargs.farg[0], |
246 |
greg |
1.1 |
m->oargs.farg[1], |
247 |
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m->oargs.farg[2]); |
248 |
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/* get roughness */ |
249 |
greg |
2.2 |
nd.specfl = 0; |
250 |
greg |
1.3 |
nd.alpha2 = m->oargs.farg[4]; |
251 |
greg |
2.2 |
if ((nd.alpha2 *= nd.alpha2) <= FTINY) |
252 |
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nd.specfl |= SP_PURE; |
253 |
greg |
2.29 |
if (r->ro != NULL && isflat(r->ro->otype)) |
254 |
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nd.specfl |= SP_FLAT; |
255 |
greg |
1.1 |
/* get modifiers */ |
256 |
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raytexture(r, m->omod); |
257 |
greg |
2.29 |
if (hastexture = DOT(r->pert,r->pert) > FTINY*FTINY) |
258 |
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nd.pdot = raynormal(nd.pnorm, r); /* perturb normal */ |
259 |
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else { |
260 |
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VCOPY(nd.pnorm, r->ron); |
261 |
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nd.pdot = r->rod; |
262 |
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} |
263 |
greg |
1.13 |
if (nd.pdot < .001) |
264 |
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nd.pdot = .001; /* non-zero for dirnorm() */ |
265 |
greg |
1.3 |
multcolor(nd.mcolor, r->pcol); /* modify material color */ |
266 |
greg |
2.29 |
mirtest = transtest = 0; |
267 |
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mirdist = transdist = r->rot; |
268 |
greg |
2.30 |
nd.rspec = m->oargs.farg[3]; |
269 |
greg |
2.38 |
/* compute Fresnel approx. */ |
270 |
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if (nd.specfl & SP_PURE && nd.rspec > FTINY) { |
271 |
|
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fest = FRESNE(r->rod); |
272 |
|
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nd.rspec += fest*(1. - nd.rspec); |
273 |
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} else |
274 |
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fest = 0.; |
275 |
greg |
1.3 |
/* compute transmission */ |
276 |
greg |
1.1 |
if (m->otype == MAT_TRANS) { |
277 |
greg |
1.3 |
nd.trans = m->oargs.farg[5]*(1.0 - nd.rspec); |
278 |
|
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nd.tspec = nd.trans * m->oargs.farg[6]; |
279 |
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nd.tdiff = nd.trans - nd.tspec; |
280 |
greg |
2.2 |
if (nd.tspec > FTINY) { |
281 |
|
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nd.specfl |= SP_TRAN; |
282 |
greg |
2.5 |
/* check threshold */ |
283 |
greg |
2.25 |
if (!(nd.specfl & SP_PURE) && |
284 |
|
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specthresh >= nd.tspec-FTINY) |
285 |
greg |
2.5 |
nd.specfl |= SP_TBLT; |
286 |
greg |
2.29 |
if (!hastexture || r->crtype & SHADOW) { |
287 |
greg |
2.2 |
VCOPY(nd.prdir, r->rdir); |
288 |
|
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transtest = 2; |
289 |
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} else { |
290 |
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for (i = 0; i < 3; i++) /* perturb */ |
291 |
greg |
2.19 |
nd.prdir[i] = r->rdir[i] - r->pert[i]; |
292 |
greg |
2.7 |
if (DOT(nd.prdir, r->ron) < -FTINY) |
293 |
|
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normalize(nd.prdir); /* OK */ |
294 |
|
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else |
295 |
|
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VCOPY(nd.prdir, r->rdir); |
296 |
greg |
2.2 |
} |
297 |
greg |
1.14 |
} |
298 |
greg |
1.1 |
} else |
299 |
greg |
1.3 |
nd.tdiff = nd.tspec = nd.trans = 0.0; |
300 |
greg |
1.1 |
/* transmitted ray */ |
301 |
gregl |
2.36 |
if ((nd.specfl&(SP_TRAN|SP_PURE|SP_TBLT)) == (SP_TRAN|SP_PURE)) { |
302 |
greg |
1.3 |
RAY lr; |
303 |
|
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if (rayorigin(&lr, r, TRANS, nd.tspec) == 0) { |
304 |
greg |
1.14 |
VCOPY(lr.rdir, nd.prdir); |
305 |
greg |
1.1 |
rayvalue(&lr); |
306 |
greg |
1.3 |
scalecolor(lr.rcol, nd.tspec); |
307 |
greg |
1.8 |
multcolor(lr.rcol, nd.mcolor); /* modified by color */ |
308 |
greg |
1.1 |
addcolor(r->rcol, lr.rcol); |
309 |
greg |
1.9 |
transtest *= bright(lr.rcol); |
310 |
|
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transdist = r->rot + lr.rt; |
311 |
greg |
1.1 |
} |
312 |
greg |
2.11 |
} else |
313 |
|
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transtest = 0; |
314 |
greg |
2.2 |
|
315 |
greg |
2.29 |
if (r->crtype & SHADOW) { /* the rest is shadow */ |
316 |
|
|
r->rt = transdist; |
317 |
greg |
2.27 |
return(1); |
318 |
greg |
2.30 |
} |
319 |
|
|
/* get specular reflection */ |
320 |
|
|
if (nd.rspec > FTINY) { |
321 |
|
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nd.specfl |= SP_REFL; |
322 |
|
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/* compute specular color */ |
323 |
greg |
2.38 |
if (m->otype != MAT_METAL) { |
324 |
|
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setcolor(nd.scolor, nd.rspec, nd.rspec, nd.rspec); |
325 |
|
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} else if (fest > FTINY) { |
326 |
|
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d = nd.rspec*(1. - fest); |
327 |
|
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for (i = 0; i < 3; i++) |
328 |
|
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nd.scolor[i] = fest + nd.mcolor[i]*d; |
329 |
|
|
} else { |
330 |
greg |
2.30 |
copycolor(nd.scolor, nd.mcolor); |
331 |
greg |
2.38 |
scalecolor(nd.scolor, nd.rspec); |
332 |
|
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} |
333 |
greg |
2.30 |
/* check threshold */ |
334 |
|
|
if (!(nd.specfl & SP_PURE) && specthresh >= nd.rspec-FTINY) |
335 |
|
|
nd.specfl |= SP_RBLT; |
336 |
|
|
/* compute reflected ray */ |
337 |
|
|
for (i = 0; i < 3; i++) |
338 |
|
|
nd.vrefl[i] = r->rdir[i] + 2.*nd.pdot*nd.pnorm[i]; |
339 |
|
|
/* penetration? */ |
340 |
|
|
if (hastexture && DOT(nd.vrefl, r->ron) <= FTINY) |
341 |
|
|
for (i = 0; i < 3; i++) /* safety measure */ |
342 |
|
|
nd.vrefl[i] = r->rdir[i] + 2.*r->rod*r->ron[i]; |
343 |
gregl |
2.36 |
} |
344 |
|
|
/* reflected ray */ |
345 |
|
|
if ((nd.specfl&(SP_REFL|SP_PURE|SP_RBLT)) == (SP_REFL|SP_PURE)) { |
346 |
|
|
RAY lr; |
347 |
|
|
if (rayorigin(&lr, r, REFLECTED, nd.rspec) == 0) { |
348 |
|
|
VCOPY(lr.rdir, nd.vrefl); |
349 |
|
|
rayvalue(&lr); |
350 |
|
|
multcolor(lr.rcol, nd.scolor); |
351 |
|
|
addcolor(r->rcol, lr.rcol); |
352 |
|
|
if (!hastexture && nd.specfl & SP_FLAT) { |
353 |
|
|
mirtest = 2.*bright(lr.rcol); |
354 |
|
|
mirdist = r->rot + lr.rt; |
355 |
greg |
2.30 |
} |
356 |
|
|
} |
357 |
greg |
2.29 |
} |
358 |
greg |
1.1 |
/* diffuse reflection */ |
359 |
greg |
1.3 |
nd.rdiff = 1.0 - nd.trans - nd.rspec; |
360 |
greg |
1.1 |
|
361 |
greg |
2.2 |
if (nd.specfl & SP_PURE && nd.rdiff <= FTINY && nd.tdiff <= FTINY) |
362 |
greg |
2.27 |
return(1); /* 100% pure specular */ |
363 |
greg |
2.3 |
|
364 |
gregl |
2.36 |
if (!(nd.specfl & SP_PURE)) |
365 |
|
|
gaussamp(r, &nd); /* checks *BLT flags */ |
366 |
greg |
2.2 |
|
367 |
greg |
1.3 |
if (nd.rdiff > FTINY) { /* ambient from this side */ |
368 |
greg |
2.31 |
ambient(ctmp, r, hastexture?nd.pnorm:r->ron); |
369 |
greg |
2.5 |
if (nd.specfl & SP_RBLT) |
370 |
|
|
scalecolor(ctmp, 1.0-nd.trans); |
371 |
|
|
else |
372 |
|
|
scalecolor(ctmp, nd.rdiff); |
373 |
greg |
1.3 |
multcolor(ctmp, nd.mcolor); /* modified by material color */ |
374 |
greg |
1.2 |
addcolor(r->rcol, ctmp); /* add to returned color */ |
375 |
|
|
} |
376 |
greg |
1.3 |
if (nd.tdiff > FTINY) { /* ambient from other side */ |
377 |
greg |
1.1 |
flipsurface(r); |
378 |
greg |
2.32 |
if (hastexture) { |
379 |
|
|
FVECT bnorm; |
380 |
|
|
bnorm[0] = -nd.pnorm[0]; |
381 |
|
|
bnorm[1] = -nd.pnorm[1]; |
382 |
|
|
bnorm[2] = -nd.pnorm[2]; |
383 |
|
|
ambient(ctmp, r, bnorm); |
384 |
|
|
} else |
385 |
|
|
ambient(ctmp, r, r->ron); |
386 |
greg |
2.5 |
if (nd.specfl & SP_TBLT) |
387 |
|
|
scalecolor(ctmp, nd.trans); |
388 |
|
|
else |
389 |
|
|
scalecolor(ctmp, nd.tdiff); |
390 |
greg |
1.13 |
multcolor(ctmp, nd.mcolor); /* modified by color */ |
391 |
greg |
1.1 |
addcolor(r->rcol, ctmp); |
392 |
|
|
flipsurface(r); |
393 |
|
|
} |
394 |
greg |
1.3 |
/* add direct component */ |
395 |
|
|
direct(r, dirnorm, &nd); |
396 |
greg |
1.9 |
/* check distance */ |
397 |
greg |
2.29 |
d = bright(r->rcol); |
398 |
|
|
if (transtest > d) |
399 |
greg |
1.9 |
r->rt = transdist; |
400 |
greg |
2.29 |
else if (mirtest > d) |
401 |
|
|
r->rt = mirdist; |
402 |
greg |
2.27 |
|
403 |
|
|
return(1); |
404 |
greg |
2.2 |
} |
405 |
|
|
|
406 |
|
|
|
407 |
greg |
2.38 |
static void |
408 |
greg |
2.2 |
gaussamp(r, np) /* sample gaussian specular */ |
409 |
|
|
RAY *r; |
410 |
|
|
register NORMDAT *np; |
411 |
|
|
{ |
412 |
|
|
RAY sr; |
413 |
|
|
FVECT u, v, h; |
414 |
|
|
double rv[2]; |
415 |
|
|
double d, sinp, cosp; |
416 |
greg |
2.34 |
int niter; |
417 |
greg |
2.2 |
register int i; |
418 |
greg |
2.13 |
/* quick test */ |
419 |
|
|
if ((np->specfl & (SP_REFL|SP_RBLT)) != SP_REFL && |
420 |
|
|
(np->specfl & (SP_TRAN|SP_TBLT)) != SP_TRAN) |
421 |
|
|
return; |
422 |
greg |
2.2 |
/* set up sample coordinates */ |
423 |
|
|
v[0] = v[1] = v[2] = 0.0; |
424 |
|
|
for (i = 0; i < 3; i++) |
425 |
|
|
if (np->pnorm[i] < 0.6 && np->pnorm[i] > -0.6) |
426 |
|
|
break; |
427 |
|
|
v[i] = 1.0; |
428 |
|
|
fcross(u, v, np->pnorm); |
429 |
|
|
normalize(u); |
430 |
|
|
fcross(v, np->pnorm, u); |
431 |
|
|
/* compute reflection */ |
432 |
greg |
2.5 |
if ((np->specfl & (SP_REFL|SP_RBLT)) == SP_REFL && |
433 |
greg |
2.2 |
rayorigin(&sr, r, SPECULAR, np->rspec) == 0) { |
434 |
|
|
dimlist[ndims++] = (int)np->mp; |
435 |
greg |
2.34 |
for (niter = 0; niter < MAXITER; niter++) { |
436 |
|
|
if (niter) |
437 |
|
|
d = frandom(); |
438 |
|
|
else |
439 |
|
|
d = urand(ilhash(dimlist,ndims)+samplendx); |
440 |
|
|
multisamp(rv, 2, d); |
441 |
|
|
d = 2.0*PI * rv[0]; |
442 |
gwlarson |
2.37 |
cosp = tcos(d); |
443 |
|
|
sinp = tsin(d); |
444 |
greg |
2.34 |
rv[1] = 1.0 - specjitter*rv[1]; |
445 |
|
|
if (rv[1] <= FTINY) |
446 |
|
|
d = 1.0; |
447 |
|
|
else |
448 |
|
|
d = sqrt( np->alpha2 * -log(rv[1]) ); |
449 |
|
|
for (i = 0; i < 3; i++) |
450 |
|
|
h[i] = np->pnorm[i] + d*(cosp*u[i] + sinp*v[i]); |
451 |
|
|
d = -2.0 * DOT(h, r->rdir) / (1.0 + d*d); |
452 |
|
|
for (i = 0; i < 3; i++) |
453 |
|
|
sr.rdir[i] = r->rdir[i] + d*h[i]; |
454 |
|
|
if (DOT(sr.rdir, r->ron) > FTINY) { |
455 |
|
|
rayvalue(&sr); |
456 |
|
|
multcolor(sr.rcol, np->scolor); |
457 |
|
|
addcolor(r->rcol, sr.rcol); |
458 |
|
|
break; |
459 |
|
|
} |
460 |
|
|
} |
461 |
greg |
2.2 |
ndims--; |
462 |
|
|
} |
463 |
|
|
/* compute transmission */ |
464 |
greg |
2.8 |
if ((np->specfl & (SP_TRAN|SP_TBLT)) == SP_TRAN && |
465 |
|
|
rayorigin(&sr, r, SPECULAR, np->tspec) == 0) { |
466 |
|
|
dimlist[ndims++] = (int)np->mp; |
467 |
greg |
2.34 |
for (niter = 0; niter < MAXITER; niter++) { |
468 |
|
|
if (niter) |
469 |
|
|
d = frandom(); |
470 |
|
|
else |
471 |
|
|
d = urand(ilhash(dimlist,ndims)+1823+samplendx); |
472 |
|
|
multisamp(rv, 2, d); |
473 |
|
|
d = 2.0*PI * rv[0]; |
474 |
gwlarson |
2.37 |
cosp = tcos(d); |
475 |
|
|
sinp = tsin(d); |
476 |
greg |
2.34 |
rv[1] = 1.0 - specjitter*rv[1]; |
477 |
|
|
if (rv[1] <= FTINY) |
478 |
|
|
d = 1.0; |
479 |
|
|
else |
480 |
gwlarson |
2.37 |
d = sqrt( np->alpha2 * -log(rv[1]) ); |
481 |
greg |
2.34 |
for (i = 0; i < 3; i++) |
482 |
|
|
sr.rdir[i] = np->prdir[i] + d*(cosp*u[i] + sinp*v[i]); |
483 |
|
|
if (DOT(sr.rdir, r->ron) < -FTINY) { |
484 |
|
|
normalize(sr.rdir); /* OK, normalize */ |
485 |
|
|
rayvalue(&sr); |
486 |
|
|
scalecolor(sr.rcol, np->tspec); |
487 |
|
|
multcolor(sr.rcol, np->mcolor); /* modified */ |
488 |
|
|
addcolor(r->rcol, sr.rcol); |
489 |
|
|
break; |
490 |
|
|
} |
491 |
|
|
} |
492 |
greg |
2.8 |
ndims--; |
493 |
|
|
} |
494 |
greg |
1.1 |
} |