1 |
greg |
1.1 |
#ifndef lint |
2 |
greg |
2.41 |
static const char RCSid[] = "$Id$"; |
3 |
greg |
1.1 |
#endif |
4 |
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/* |
5 |
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* normal.c - shading function for normal materials. |
6 |
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* |
7 |
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* 8/19/85 |
8 |
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* 12/19/85 - added stuff for metals. |
9 |
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* 6/26/87 - improved specular model. |
10 |
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* 9/28/87 - added model for translucent materials. |
11 |
greg |
2.2 |
* Later changes described in delta comments. |
12 |
greg |
1.1 |
*/ |
13 |
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|
14 |
greg |
2.39 |
#include "copyright.h" |
15 |
greg |
2.38 |
|
16 |
greg |
1.1 |
#include "ray.h" |
17 |
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18 |
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#include "otypes.h" |
19 |
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20 |
greg |
2.2 |
#include "random.h" |
21 |
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22 |
greg |
2.34 |
#ifndef MAXITER |
23 |
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#define MAXITER 10 /* maximum # specular ray attempts */ |
24 |
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#endif |
25 |
greg |
2.38 |
/* estimate of Fresnel function */ |
26 |
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#define FRESNE(ci) (exp(-6.0*(ci)) - 0.00247875217) |
27 |
greg |
2.34 |
|
28 |
greg |
2.38 |
static void gaussamp(); |
29 |
greg |
2.24 |
|
30 |
greg |
1.1 |
/* |
31 |
greg |
2.22 |
* This routine implements the isotropic Gaussian |
32 |
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* model described by Ward in Siggraph `92 article. |
33 |
greg |
1.1 |
* We orient the surface towards the incoming ray, so a single |
34 |
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* surface can be used to represent an infinitely thin object. |
35 |
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* |
36 |
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* Arguments for MAT_PLASTIC and MAT_METAL are: |
37 |
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* red grn blu specular-frac. facet-slope |
38 |
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* |
39 |
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* Arguments for MAT_TRANS are: |
40 |
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* red grn blu rspec rough trans tspec |
41 |
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*/ |
42 |
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43 |
greg |
2.2 |
/* specularity flags */ |
44 |
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#define SP_REFL 01 /* has reflected specular component */ |
45 |
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#define SP_TRAN 02 /* has transmitted specular */ |
46 |
greg |
2.11 |
#define SP_PURE 04 /* purely specular (zero roughness) */ |
47 |
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#define SP_FLAT 010 /* flat reflecting surface */ |
48 |
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#define SP_RBLT 020 /* reflection below sample threshold */ |
49 |
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#define SP_TBLT 040 /* transmission below threshold */ |
50 |
greg |
1.1 |
|
51 |
greg |
1.3 |
typedef struct { |
52 |
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OBJREC *mp; /* material pointer */ |
53 |
greg |
2.16 |
RAY *rp; /* ray pointer */ |
54 |
greg |
2.2 |
short specfl; /* specularity flags, defined above */ |
55 |
greg |
1.1 |
COLOR mcolor; /* color of this material */ |
56 |
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COLOR scolor; /* color of specular component */ |
57 |
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FVECT vrefl; /* vector in direction of reflected ray */ |
58 |
greg |
1.14 |
FVECT prdir; /* vector in transmitted direction */ |
59 |
greg |
2.2 |
double alpha2; /* roughness squared */ |
60 |
greg |
1.1 |
double rdiff, rspec; /* reflected specular, diffuse */ |
61 |
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double trans; /* transmissivity */ |
62 |
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double tdiff, tspec; /* transmitted specular, diffuse */ |
63 |
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FVECT pnorm; /* perturbed surface normal */ |
64 |
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double pdot; /* perturbed dot product */ |
65 |
greg |
1.3 |
} NORMDAT; /* normal material data */ |
66 |
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67 |
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68 |
greg |
2.38 |
static void |
69 |
greg |
1.3 |
dirnorm(cval, np, ldir, omega) /* compute source contribution */ |
70 |
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COLOR cval; /* returned coefficient */ |
71 |
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register NORMDAT *np; /* material data */ |
72 |
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FVECT ldir; /* light source direction */ |
73 |
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double omega; /* light source size */ |
74 |
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{ |
75 |
greg |
1.1 |
double ldot; |
76 |
greg |
2.38 |
double ldiff; |
77 |
greg |
2.16 |
double dtmp, d2; |
78 |
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FVECT vtmp; |
79 |
greg |
1.3 |
COLOR ctmp; |
80 |
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81 |
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setcolor(cval, 0.0, 0.0, 0.0); |
82 |
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83 |
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ldot = DOT(np->pnorm, ldir); |
84 |
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85 |
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if (ldot < 0.0 ? np->trans <= FTINY : np->trans >= 1.0-FTINY) |
86 |
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return; /* wrong side */ |
87 |
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88 |
greg |
2.38 |
/* Fresnel estimate */ |
89 |
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ldiff = np->rdiff; |
90 |
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if (np->specfl & SP_PURE && (np->rspec > FTINY & ldiff > FTINY)) |
91 |
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ldiff *= 1. - FRESNE(fabs(ldot)); |
92 |
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93 |
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if (ldot > FTINY && ldiff > FTINY) { |
94 |
greg |
1.3 |
/* |
95 |
greg |
1.4 |
* Compute and add diffuse reflected component to returned |
96 |
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* color. The diffuse reflected component will always be |
97 |
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* modified by the color of the material. |
98 |
greg |
1.3 |
*/ |
99 |
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copycolor(ctmp, np->mcolor); |
100 |
greg |
2.38 |
dtmp = ldot * omega * ldiff / PI; |
101 |
greg |
1.3 |
scalecolor(ctmp, dtmp); |
102 |
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addcolor(cval, ctmp); |
103 |
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} |
104 |
greg |
2.2 |
if (ldot > FTINY && (np->specfl&(SP_REFL|SP_PURE)) == SP_REFL) { |
105 |
greg |
1.3 |
/* |
106 |
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* Compute specular reflection coefficient using |
107 |
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* gaussian distribution model. |
108 |
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*/ |
109 |
greg |
2.3 |
/* roughness */ |
110 |
greg |
2.16 |
dtmp = np->alpha2; |
111 |
greg |
2.3 |
/* + source if flat */ |
112 |
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if (np->specfl & SP_FLAT) |
113 |
greg |
2.16 |
dtmp += omega/(4.0*PI); |
114 |
greg |
2.23 |
/* half vector */ |
115 |
greg |
2.18 |
vtmp[0] = ldir[0] - np->rp->rdir[0]; |
116 |
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vtmp[1] = ldir[1] - np->rp->rdir[1]; |
117 |
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vtmp[2] = ldir[2] - np->rp->rdir[2]; |
118 |
greg |
2.16 |
d2 = DOT(vtmp, np->pnorm); |
119 |
greg |
2.23 |
d2 *= d2; |
120 |
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d2 = (DOT(vtmp,vtmp) - d2) / d2; |
121 |
greg |
1.3 |
/* gaussian */ |
122 |
greg |
2.16 |
dtmp = exp(-d2/dtmp)/(4.*PI*dtmp); |
123 |
greg |
1.3 |
/* worth using? */ |
124 |
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if (dtmp > FTINY) { |
125 |
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copycolor(ctmp, np->scolor); |
126 |
greg |
2.14 |
dtmp *= omega * sqrt(ldot/np->pdot); |
127 |
greg |
1.3 |
scalecolor(ctmp, dtmp); |
128 |
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addcolor(cval, ctmp); |
129 |
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} |
130 |
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} |
131 |
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if (ldot < -FTINY && np->tdiff > FTINY) { |
132 |
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/* |
133 |
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* Compute diffuse transmission. |
134 |
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*/ |
135 |
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copycolor(ctmp, np->mcolor); |
136 |
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dtmp = -ldot * omega * np->tdiff / PI; |
137 |
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scalecolor(ctmp, dtmp); |
138 |
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addcolor(cval, ctmp); |
139 |
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} |
140 |
greg |
2.2 |
if (ldot < -FTINY && (np->specfl&(SP_TRAN|SP_PURE)) == SP_TRAN) { |
141 |
greg |
1.3 |
/* |
142 |
greg |
1.4 |
* Compute specular transmission. Specular transmission |
143 |
greg |
1.13 |
* is always modified by material color. |
144 |
greg |
1.3 |
*/ |
145 |
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/* roughness + source */ |
146 |
greg |
2.19 |
dtmp = np->alpha2 + omega/PI; |
147 |
greg |
1.3 |
/* gaussian */ |
148 |
greg |
2.21 |
dtmp = exp((2.*DOT(np->prdir,ldir)-2.)/dtmp)/(PI*dtmp); |
149 |
greg |
1.3 |
/* worth using? */ |
150 |
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if (dtmp > FTINY) { |
151 |
greg |
1.13 |
copycolor(ctmp, np->mcolor); |
152 |
greg |
2.18 |
dtmp *= np->tspec * omega * sqrt(-ldot/np->pdot); |
153 |
greg |
1.13 |
scalecolor(ctmp, dtmp); |
154 |
greg |
1.3 |
addcolor(cval, ctmp); |
155 |
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} |
156 |
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} |
157 |
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} |
158 |
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159 |
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160 |
greg |
2.38 |
int |
161 |
greg |
2.2 |
m_normal(m, r) /* color a ray that hit something normal */ |
162 |
greg |
1.3 |
register OBJREC *m; |
163 |
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register RAY *r; |
164 |
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{ |
165 |
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NORMDAT nd; |
166 |
greg |
2.38 |
double fest; |
167 |
greg |
1.9 |
double transtest, transdist; |
168 |
greg |
2.29 |
double mirtest, mirdist; |
169 |
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int hastexture; |
170 |
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double d; |
171 |
greg |
1.1 |
COLOR ctmp; |
172 |
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register int i; |
173 |
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/* easy shadow test */ |
174 |
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if (r->crtype & SHADOW && m->otype != MAT_TRANS) |
175 |
greg |
2.27 |
return(1); |
176 |
greg |
2.2 |
|
177 |
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if (m->oargs.nfargs != (m->otype == MAT_TRANS ? 7 : 5)) |
178 |
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objerror(m, USER, "bad number of arguments"); |
179 |
greg |
2.29 |
/* check for back side */ |
180 |
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if (r->rod < 0.0) { |
181 |
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if (!backvis && m->otype != MAT_TRANS) { |
182 |
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raytrans(r); |
183 |
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return(1); |
184 |
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} |
185 |
greg |
2.40 |
raytexture(r, m->omod); |
186 |
greg |
2.29 |
flipsurface(r); /* reorient if backvis */ |
187 |
greg |
2.40 |
} else |
188 |
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raytexture(r, m->omod); |
189 |
greg |
1.3 |
nd.mp = m; |
190 |
greg |
2.16 |
nd.rp = r; |
191 |
greg |
1.1 |
/* get material color */ |
192 |
greg |
1.3 |
setcolor(nd.mcolor, m->oargs.farg[0], |
193 |
greg |
1.1 |
m->oargs.farg[1], |
194 |
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m->oargs.farg[2]); |
195 |
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/* get roughness */ |
196 |
greg |
2.2 |
nd.specfl = 0; |
197 |
greg |
1.3 |
nd.alpha2 = m->oargs.farg[4]; |
198 |
greg |
2.2 |
if ((nd.alpha2 *= nd.alpha2) <= FTINY) |
199 |
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nd.specfl |= SP_PURE; |
200 |
greg |
2.40 |
|
201 |
greg |
2.41 |
if (hastexture = (DOT(r->pert,r->pert) > FTINY*FTINY)) { |
202 |
greg |
2.29 |
nd.pdot = raynormal(nd.pnorm, r); /* perturb normal */ |
203 |
greg |
2.41 |
} else { |
204 |
greg |
2.29 |
VCOPY(nd.pnorm, r->ron); |
205 |
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nd.pdot = r->rod; |
206 |
greg |
2.41 |
if (r->ro != NULL && isflat(r->ro->otype)) |
207 |
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nd.specfl |= SP_FLAT; |
208 |
greg |
2.29 |
} |
209 |
greg |
1.13 |
if (nd.pdot < .001) |
210 |
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nd.pdot = .001; /* non-zero for dirnorm() */ |
211 |
greg |
1.3 |
multcolor(nd.mcolor, r->pcol); /* modify material color */ |
212 |
greg |
2.29 |
mirtest = transtest = 0; |
213 |
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mirdist = transdist = r->rot; |
214 |
greg |
2.30 |
nd.rspec = m->oargs.farg[3]; |
215 |
greg |
2.38 |
/* compute Fresnel approx. */ |
216 |
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if (nd.specfl & SP_PURE && nd.rspec > FTINY) { |
217 |
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fest = FRESNE(r->rod); |
218 |
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nd.rspec += fest*(1. - nd.rspec); |
219 |
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} else |
220 |
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fest = 0.; |
221 |
greg |
1.3 |
/* compute transmission */ |
222 |
greg |
1.1 |
if (m->otype == MAT_TRANS) { |
223 |
greg |
1.3 |
nd.trans = m->oargs.farg[5]*(1.0 - nd.rspec); |
224 |
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nd.tspec = nd.trans * m->oargs.farg[6]; |
225 |
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nd.tdiff = nd.trans - nd.tspec; |
226 |
greg |
2.2 |
if (nd.tspec > FTINY) { |
227 |
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nd.specfl |= SP_TRAN; |
228 |
greg |
2.5 |
/* check threshold */ |
229 |
greg |
2.25 |
if (!(nd.specfl & SP_PURE) && |
230 |
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specthresh >= nd.tspec-FTINY) |
231 |
greg |
2.5 |
nd.specfl |= SP_TBLT; |
232 |
greg |
2.29 |
if (!hastexture || r->crtype & SHADOW) { |
233 |
greg |
2.2 |
VCOPY(nd.prdir, r->rdir); |
234 |
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transtest = 2; |
235 |
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} else { |
236 |
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for (i = 0; i < 3; i++) /* perturb */ |
237 |
greg |
2.19 |
nd.prdir[i] = r->rdir[i] - r->pert[i]; |
238 |
greg |
2.7 |
if (DOT(nd.prdir, r->ron) < -FTINY) |
239 |
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normalize(nd.prdir); /* OK */ |
240 |
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else |
241 |
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VCOPY(nd.prdir, r->rdir); |
242 |
greg |
2.2 |
} |
243 |
greg |
1.14 |
} |
244 |
greg |
1.1 |
} else |
245 |
greg |
1.3 |
nd.tdiff = nd.tspec = nd.trans = 0.0; |
246 |
greg |
1.1 |
/* transmitted ray */ |
247 |
gregl |
2.36 |
if ((nd.specfl&(SP_TRAN|SP_PURE|SP_TBLT)) == (SP_TRAN|SP_PURE)) { |
248 |
greg |
1.3 |
RAY lr; |
249 |
|
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if (rayorigin(&lr, r, TRANS, nd.tspec) == 0) { |
250 |
greg |
1.14 |
VCOPY(lr.rdir, nd.prdir); |
251 |
greg |
1.1 |
rayvalue(&lr); |
252 |
greg |
1.3 |
scalecolor(lr.rcol, nd.tspec); |
253 |
greg |
1.8 |
multcolor(lr.rcol, nd.mcolor); /* modified by color */ |
254 |
greg |
1.1 |
addcolor(r->rcol, lr.rcol); |
255 |
greg |
1.9 |
transtest *= bright(lr.rcol); |
256 |
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transdist = r->rot + lr.rt; |
257 |
greg |
1.1 |
} |
258 |
greg |
2.11 |
} else |
259 |
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transtest = 0; |
260 |
greg |
2.2 |
|
261 |
greg |
2.29 |
if (r->crtype & SHADOW) { /* the rest is shadow */ |
262 |
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r->rt = transdist; |
263 |
greg |
2.27 |
return(1); |
264 |
greg |
2.30 |
} |
265 |
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/* get specular reflection */ |
266 |
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if (nd.rspec > FTINY) { |
267 |
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nd.specfl |= SP_REFL; |
268 |
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/* compute specular color */ |
269 |
greg |
2.38 |
if (m->otype != MAT_METAL) { |
270 |
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setcolor(nd.scolor, nd.rspec, nd.rspec, nd.rspec); |
271 |
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} else if (fest > FTINY) { |
272 |
|
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d = nd.rspec*(1. - fest); |
273 |
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for (i = 0; i < 3; i++) |
274 |
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nd.scolor[i] = fest + nd.mcolor[i]*d; |
275 |
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} else { |
276 |
greg |
2.30 |
copycolor(nd.scolor, nd.mcolor); |
277 |
greg |
2.38 |
scalecolor(nd.scolor, nd.rspec); |
278 |
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} |
279 |
greg |
2.30 |
/* check threshold */ |
280 |
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if (!(nd.specfl & SP_PURE) && specthresh >= nd.rspec-FTINY) |
281 |
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nd.specfl |= SP_RBLT; |
282 |
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/* compute reflected ray */ |
283 |
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for (i = 0; i < 3; i++) |
284 |
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nd.vrefl[i] = r->rdir[i] + 2.*nd.pdot*nd.pnorm[i]; |
285 |
|
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/* penetration? */ |
286 |
|
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if (hastexture && DOT(nd.vrefl, r->ron) <= FTINY) |
287 |
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for (i = 0; i < 3; i++) /* safety measure */ |
288 |
|
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nd.vrefl[i] = r->rdir[i] + 2.*r->rod*r->ron[i]; |
289 |
gregl |
2.36 |
} |
290 |
|
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/* reflected ray */ |
291 |
|
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if ((nd.specfl&(SP_REFL|SP_PURE|SP_RBLT)) == (SP_REFL|SP_PURE)) { |
292 |
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RAY lr; |
293 |
|
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if (rayorigin(&lr, r, REFLECTED, nd.rspec) == 0) { |
294 |
|
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VCOPY(lr.rdir, nd.vrefl); |
295 |
|
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rayvalue(&lr); |
296 |
|
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multcolor(lr.rcol, nd.scolor); |
297 |
|
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addcolor(r->rcol, lr.rcol); |
298 |
|
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if (!hastexture && nd.specfl & SP_FLAT) { |
299 |
|
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mirtest = 2.*bright(lr.rcol); |
300 |
|
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mirdist = r->rot + lr.rt; |
301 |
greg |
2.30 |
} |
302 |
|
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} |
303 |
greg |
2.29 |
} |
304 |
greg |
1.1 |
/* diffuse reflection */ |
305 |
greg |
1.3 |
nd.rdiff = 1.0 - nd.trans - nd.rspec; |
306 |
greg |
1.1 |
|
307 |
greg |
2.2 |
if (nd.specfl & SP_PURE && nd.rdiff <= FTINY && nd.tdiff <= FTINY) |
308 |
greg |
2.27 |
return(1); /* 100% pure specular */ |
309 |
greg |
2.3 |
|
310 |
gregl |
2.36 |
if (!(nd.specfl & SP_PURE)) |
311 |
|
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gaussamp(r, &nd); /* checks *BLT flags */ |
312 |
greg |
2.2 |
|
313 |
greg |
1.3 |
if (nd.rdiff > FTINY) { /* ambient from this side */ |
314 |
greg |
2.31 |
ambient(ctmp, r, hastexture?nd.pnorm:r->ron); |
315 |
greg |
2.5 |
if (nd.specfl & SP_RBLT) |
316 |
|
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scalecolor(ctmp, 1.0-nd.trans); |
317 |
|
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else |
318 |
|
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scalecolor(ctmp, nd.rdiff); |
319 |
greg |
1.3 |
multcolor(ctmp, nd.mcolor); /* modified by material color */ |
320 |
greg |
1.2 |
addcolor(r->rcol, ctmp); /* add to returned color */ |
321 |
|
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} |
322 |
greg |
1.3 |
if (nd.tdiff > FTINY) { /* ambient from other side */ |
323 |
greg |
1.1 |
flipsurface(r); |
324 |
greg |
2.32 |
if (hastexture) { |
325 |
|
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FVECT bnorm; |
326 |
|
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bnorm[0] = -nd.pnorm[0]; |
327 |
|
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bnorm[1] = -nd.pnorm[1]; |
328 |
|
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bnorm[2] = -nd.pnorm[2]; |
329 |
|
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ambient(ctmp, r, bnorm); |
330 |
|
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} else |
331 |
|
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ambient(ctmp, r, r->ron); |
332 |
greg |
2.5 |
if (nd.specfl & SP_TBLT) |
333 |
|
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scalecolor(ctmp, nd.trans); |
334 |
|
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else |
335 |
|
|
scalecolor(ctmp, nd.tdiff); |
336 |
greg |
1.13 |
multcolor(ctmp, nd.mcolor); /* modified by color */ |
337 |
greg |
1.1 |
addcolor(r->rcol, ctmp); |
338 |
|
|
flipsurface(r); |
339 |
|
|
} |
340 |
greg |
1.3 |
/* add direct component */ |
341 |
|
|
direct(r, dirnorm, &nd); |
342 |
greg |
1.9 |
/* check distance */ |
343 |
greg |
2.29 |
d = bright(r->rcol); |
344 |
|
|
if (transtest > d) |
345 |
greg |
1.9 |
r->rt = transdist; |
346 |
greg |
2.29 |
else if (mirtest > d) |
347 |
|
|
r->rt = mirdist; |
348 |
greg |
2.27 |
|
349 |
|
|
return(1); |
350 |
greg |
2.2 |
} |
351 |
|
|
|
352 |
|
|
|
353 |
greg |
2.38 |
static void |
354 |
greg |
2.2 |
gaussamp(r, np) /* sample gaussian specular */ |
355 |
|
|
RAY *r; |
356 |
|
|
register NORMDAT *np; |
357 |
|
|
{ |
358 |
|
|
RAY sr; |
359 |
|
|
FVECT u, v, h; |
360 |
|
|
double rv[2]; |
361 |
|
|
double d, sinp, cosp; |
362 |
greg |
2.34 |
int niter; |
363 |
greg |
2.2 |
register int i; |
364 |
greg |
2.13 |
/* quick test */ |
365 |
|
|
if ((np->specfl & (SP_REFL|SP_RBLT)) != SP_REFL && |
366 |
|
|
(np->specfl & (SP_TRAN|SP_TBLT)) != SP_TRAN) |
367 |
|
|
return; |
368 |
greg |
2.2 |
/* set up sample coordinates */ |
369 |
|
|
v[0] = v[1] = v[2] = 0.0; |
370 |
|
|
for (i = 0; i < 3; i++) |
371 |
|
|
if (np->pnorm[i] < 0.6 && np->pnorm[i] > -0.6) |
372 |
|
|
break; |
373 |
|
|
v[i] = 1.0; |
374 |
|
|
fcross(u, v, np->pnorm); |
375 |
|
|
normalize(u); |
376 |
|
|
fcross(v, np->pnorm, u); |
377 |
|
|
/* compute reflection */ |
378 |
greg |
2.5 |
if ((np->specfl & (SP_REFL|SP_RBLT)) == SP_REFL && |
379 |
greg |
2.2 |
rayorigin(&sr, r, SPECULAR, np->rspec) == 0) { |
380 |
|
|
dimlist[ndims++] = (int)np->mp; |
381 |
greg |
2.34 |
for (niter = 0; niter < MAXITER; niter++) { |
382 |
|
|
if (niter) |
383 |
|
|
d = frandom(); |
384 |
|
|
else |
385 |
|
|
d = urand(ilhash(dimlist,ndims)+samplendx); |
386 |
|
|
multisamp(rv, 2, d); |
387 |
|
|
d = 2.0*PI * rv[0]; |
388 |
gwlarson |
2.37 |
cosp = tcos(d); |
389 |
|
|
sinp = tsin(d); |
390 |
greg |
2.34 |
rv[1] = 1.0 - specjitter*rv[1]; |
391 |
|
|
if (rv[1] <= FTINY) |
392 |
|
|
d = 1.0; |
393 |
|
|
else |
394 |
|
|
d = sqrt( np->alpha2 * -log(rv[1]) ); |
395 |
|
|
for (i = 0; i < 3; i++) |
396 |
|
|
h[i] = np->pnorm[i] + d*(cosp*u[i] + sinp*v[i]); |
397 |
|
|
d = -2.0 * DOT(h, r->rdir) / (1.0 + d*d); |
398 |
|
|
for (i = 0; i < 3; i++) |
399 |
|
|
sr.rdir[i] = r->rdir[i] + d*h[i]; |
400 |
|
|
if (DOT(sr.rdir, r->ron) > FTINY) { |
401 |
|
|
rayvalue(&sr); |
402 |
|
|
multcolor(sr.rcol, np->scolor); |
403 |
|
|
addcolor(r->rcol, sr.rcol); |
404 |
|
|
break; |
405 |
|
|
} |
406 |
|
|
} |
407 |
greg |
2.2 |
ndims--; |
408 |
|
|
} |
409 |
|
|
/* compute transmission */ |
410 |
greg |
2.8 |
if ((np->specfl & (SP_TRAN|SP_TBLT)) == SP_TRAN && |
411 |
|
|
rayorigin(&sr, r, SPECULAR, np->tspec) == 0) { |
412 |
|
|
dimlist[ndims++] = (int)np->mp; |
413 |
greg |
2.34 |
for (niter = 0; niter < MAXITER; niter++) { |
414 |
|
|
if (niter) |
415 |
|
|
d = frandom(); |
416 |
|
|
else |
417 |
|
|
d = urand(ilhash(dimlist,ndims)+1823+samplendx); |
418 |
|
|
multisamp(rv, 2, d); |
419 |
|
|
d = 2.0*PI * rv[0]; |
420 |
gwlarson |
2.37 |
cosp = tcos(d); |
421 |
|
|
sinp = tsin(d); |
422 |
greg |
2.34 |
rv[1] = 1.0 - specjitter*rv[1]; |
423 |
|
|
if (rv[1] <= FTINY) |
424 |
|
|
d = 1.0; |
425 |
|
|
else |
426 |
gwlarson |
2.37 |
d = sqrt( np->alpha2 * -log(rv[1]) ); |
427 |
greg |
2.34 |
for (i = 0; i < 3; i++) |
428 |
|
|
sr.rdir[i] = np->prdir[i] + d*(cosp*u[i] + sinp*v[i]); |
429 |
|
|
if (DOT(sr.rdir, r->ron) < -FTINY) { |
430 |
|
|
normalize(sr.rdir); /* OK, normalize */ |
431 |
|
|
rayvalue(&sr); |
432 |
|
|
scalecolor(sr.rcol, np->tspec); |
433 |
|
|
multcolor(sr.rcol, np->mcolor); /* modified */ |
434 |
|
|
addcolor(r->rcol, sr.rcol); |
435 |
|
|
break; |
436 |
|
|
} |
437 |
|
|
} |
438 |
greg |
2.8 |
ndims--; |
439 |
|
|
} |
440 |
greg |
1.1 |
} |