1 |
greg |
1.1 |
#ifndef lint |
2 |
greg |
2.62 |
static const char RCSid[] = "$Id: normal.c,v 2.61 2011/10/26 03:44:56 greg Exp $"; |
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 |
greg |
2.46 |
#include "ambient.h" |
18 |
schorsch |
2.47 |
#include "source.h" |
19 |
greg |
1.1 |
#include "otypes.h" |
20 |
schorsch |
2.47 |
#include "rtotypes.h" |
21 |
greg |
2.2 |
#include "random.h" |
22 |
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23 |
greg |
2.34 |
#ifndef MAXITER |
24 |
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#define MAXITER 10 /* maximum # specular ray attempts */ |
25 |
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#endif |
26 |
greg |
2.38 |
/* estimate of Fresnel function */ |
27 |
greg |
2.44 |
#define FRESNE(ci) (exp(-5.85*(ci)) - 0.00287989916) |
28 |
greg |
2.51 |
#define FRESTHRESH 0.017999 /* minimum specularity for approx. */ |
29 |
greg |
2.34 |
|
30 |
greg |
2.24 |
|
31 |
greg |
1.1 |
/* |
32 |
greg |
2.22 |
* This routine implements the isotropic Gaussian |
33 |
|
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* model described by Ward in Siggraph `92 article. |
34 |
greg |
1.1 |
* We orient the surface towards the incoming ray, so a single |
35 |
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* surface can be used to represent an infinitely thin object. |
36 |
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* |
37 |
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* Arguments for MAT_PLASTIC and MAT_METAL are: |
38 |
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* red grn blu specular-frac. facet-slope |
39 |
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* |
40 |
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* Arguments for MAT_TRANS are: |
41 |
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* red grn blu rspec rough trans tspec |
42 |
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*/ |
43 |
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|
44 |
greg |
2.2 |
/* specularity flags */ |
45 |
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#define SP_REFL 01 /* has reflected specular component */ |
46 |
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#define SP_TRAN 02 /* has transmitted specular */ |
47 |
greg |
2.11 |
#define SP_PURE 04 /* purely specular (zero roughness) */ |
48 |
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#define SP_FLAT 010 /* flat reflecting surface */ |
49 |
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#define SP_RBLT 020 /* reflection below sample threshold */ |
50 |
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#define SP_TBLT 040 /* transmission below threshold */ |
51 |
greg |
1.1 |
|
52 |
greg |
1.3 |
typedef struct { |
53 |
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OBJREC *mp; /* material pointer */ |
54 |
greg |
2.16 |
RAY *rp; /* ray pointer */ |
55 |
greg |
2.2 |
short specfl; /* specularity flags, defined above */ |
56 |
greg |
1.1 |
COLOR mcolor; /* color of this material */ |
57 |
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COLOR scolor; /* color of specular component */ |
58 |
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FVECT vrefl; /* vector in direction of reflected ray */ |
59 |
greg |
1.14 |
FVECT prdir; /* vector in transmitted direction */ |
60 |
greg |
2.2 |
double alpha2; /* roughness squared */ |
61 |
greg |
1.1 |
double rdiff, rspec; /* reflected specular, diffuse */ |
62 |
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double trans; /* transmissivity */ |
63 |
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double tdiff, tspec; /* transmitted specular, diffuse */ |
64 |
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FVECT pnorm; /* perturbed surface normal */ |
65 |
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double pdot; /* perturbed dot product */ |
66 |
greg |
1.3 |
} NORMDAT; /* normal material data */ |
67 |
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|
68 |
schorsch |
2.47 |
static void gaussamp(RAY *r, NORMDAT *np); |
69 |
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70 |
greg |
1.3 |
|
71 |
greg |
2.38 |
static void |
72 |
schorsch |
2.47 |
dirnorm( /* compute source contribution */ |
73 |
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COLOR cval, /* returned coefficient */ |
74 |
greg |
2.62 |
void *nnp, /* material data */ |
75 |
schorsch |
2.47 |
FVECT ldir, /* light source direction */ |
76 |
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double omega /* light source size */ |
77 |
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) |
78 |
greg |
1.3 |
{ |
79 |
greg |
2.62 |
NORMDAT *np = nnp; |
80 |
greg |
1.1 |
double ldot; |
81 |
greg |
2.49 |
double lrdiff, ltdiff; |
82 |
greg |
2.54 |
double dtmp, d2, d3, d4; |
83 |
greg |
2.16 |
FVECT vtmp; |
84 |
greg |
1.3 |
COLOR ctmp; |
85 |
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86 |
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setcolor(cval, 0.0, 0.0, 0.0); |
87 |
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88 |
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ldot = DOT(np->pnorm, ldir); |
89 |
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90 |
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if (ldot < 0.0 ? np->trans <= FTINY : np->trans >= 1.0-FTINY) |
91 |
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return; /* wrong side */ |
92 |
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93 |
greg |
2.38 |
/* Fresnel estimate */ |
94 |
greg |
2.49 |
lrdiff = np->rdiff; |
95 |
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ltdiff = np->tdiff; |
96 |
greg |
2.51 |
if (np->specfl & SP_PURE && np->rspec >= FRESTHRESH && |
97 |
greg |
2.49 |
(lrdiff > FTINY) | (ltdiff > FTINY)) { |
98 |
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dtmp = 1. - FRESNE(fabs(ldot)); |
99 |
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lrdiff *= dtmp; |
100 |
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ltdiff *= dtmp; |
101 |
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} |
102 |
greg |
2.38 |
|
103 |
greg |
2.49 |
if (ldot > FTINY && lrdiff > FTINY) { |
104 |
greg |
1.3 |
/* |
105 |
greg |
1.4 |
* Compute and add diffuse reflected component to returned |
106 |
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* color. The diffuse reflected component will always be |
107 |
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* modified by the color of the material. |
108 |
greg |
1.3 |
*/ |
109 |
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copycolor(ctmp, np->mcolor); |
110 |
greg |
2.49 |
dtmp = ldot * omega * lrdiff * (1.0/PI); |
111 |
greg |
1.3 |
scalecolor(ctmp, dtmp); |
112 |
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addcolor(cval, ctmp); |
113 |
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} |
114 |
greg |
2.2 |
if (ldot > FTINY && (np->specfl&(SP_REFL|SP_PURE)) == SP_REFL) { |
115 |
greg |
1.3 |
/* |
116 |
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* Compute specular reflection coefficient using |
117 |
greg |
2.54 |
* Gaussian distribution model. |
118 |
greg |
1.3 |
*/ |
119 |
greg |
2.3 |
/* roughness */ |
120 |
greg |
2.16 |
dtmp = np->alpha2; |
121 |
greg |
2.3 |
/* + source if flat */ |
122 |
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if (np->specfl & SP_FLAT) |
123 |
greg |
2.48 |
dtmp += omega * (0.25/PI); |
124 |
greg |
2.23 |
/* half vector */ |
125 |
greg |
2.62 |
VSUB(vtmp, ldir, np->rp->rdir); |
126 |
greg |
2.16 |
d2 = DOT(vtmp, np->pnorm); |
127 |
greg |
2.23 |
d2 *= d2; |
128 |
greg |
2.54 |
d3 = DOT(vtmp,vtmp); |
129 |
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d4 = (d3 - d2) / d2; |
130 |
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/* new W-G-M-D model */ |
131 |
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dtmp = exp(-d4/dtmp) * d3 / (PI * d2*d2 * dtmp); |
132 |
greg |
1.3 |
/* worth using? */ |
133 |
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if (dtmp > FTINY) { |
134 |
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copycolor(ctmp, np->scolor); |
135 |
greg |
2.54 |
dtmp *= ldot * omega; |
136 |
greg |
1.3 |
scalecolor(ctmp, dtmp); |
137 |
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addcolor(cval, ctmp); |
138 |
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} |
139 |
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} |
140 |
greg |
2.49 |
if (ldot < -FTINY && ltdiff > FTINY) { |
141 |
greg |
1.3 |
/* |
142 |
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* Compute diffuse transmission. |
143 |
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*/ |
144 |
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copycolor(ctmp, np->mcolor); |
145 |
greg |
2.49 |
dtmp = -ldot * omega * ltdiff * (1.0/PI); |
146 |
greg |
1.3 |
scalecolor(ctmp, dtmp); |
147 |
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addcolor(cval, ctmp); |
148 |
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} |
149 |
greg |
2.2 |
if (ldot < -FTINY && (np->specfl&(SP_TRAN|SP_PURE)) == SP_TRAN) { |
150 |
greg |
1.3 |
/* |
151 |
greg |
1.4 |
* Compute specular transmission. Specular transmission |
152 |
greg |
1.13 |
* is always modified by material color. |
153 |
greg |
1.3 |
*/ |
154 |
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/* roughness + source */ |
155 |
greg |
2.48 |
dtmp = np->alpha2 + omega*(1.0/PI); |
156 |
greg |
2.54 |
/* Gaussian */ |
157 |
greg |
2.53 |
dtmp = exp((2.*DOT(np->prdir,ldir)-2.)/dtmp)/(PI*dtmp); |
158 |
greg |
1.3 |
/* worth using? */ |
159 |
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if (dtmp > FTINY) { |
160 |
greg |
1.13 |
copycolor(ctmp, np->mcolor); |
161 |
greg |
2.52 |
dtmp *= np->tspec * omega * sqrt(-ldot/np->pdot); |
162 |
greg |
1.13 |
scalecolor(ctmp, dtmp); |
163 |
greg |
1.3 |
addcolor(cval, ctmp); |
164 |
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} |
165 |
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} |
166 |
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} |
167 |
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168 |
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169 |
greg |
2.62 |
int |
170 |
schorsch |
2.47 |
m_normal( /* color a ray that hit something normal */ |
171 |
greg |
2.62 |
OBJREC *m, |
172 |
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RAY *r |
173 |
schorsch |
2.47 |
) |
174 |
greg |
1.3 |
{ |
175 |
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NORMDAT nd; |
176 |
greg |
2.38 |
double fest; |
177 |
greg |
1.9 |
double transtest, transdist; |
178 |
greg |
2.29 |
double mirtest, mirdist; |
179 |
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int hastexture; |
180 |
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double d; |
181 |
greg |
1.1 |
COLOR ctmp; |
182 |
greg |
2.62 |
int i; |
183 |
greg |
1.1 |
/* easy shadow test */ |
184 |
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if (r->crtype & SHADOW && m->otype != MAT_TRANS) |
185 |
greg |
2.27 |
return(1); |
186 |
greg |
2.2 |
|
187 |
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if (m->oargs.nfargs != (m->otype == MAT_TRANS ? 7 : 5)) |
188 |
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objerror(m, USER, "bad number of arguments"); |
189 |
greg |
2.29 |
/* check for back side */ |
190 |
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if (r->rod < 0.0) { |
191 |
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if (!backvis && m->otype != MAT_TRANS) { |
192 |
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raytrans(r); |
193 |
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return(1); |
194 |
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} |
195 |
greg |
2.40 |
raytexture(r, m->omod); |
196 |
greg |
2.29 |
flipsurface(r); /* reorient if backvis */ |
197 |
greg |
2.40 |
} else |
198 |
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raytexture(r, m->omod); |
199 |
greg |
1.3 |
nd.mp = m; |
200 |
greg |
2.16 |
nd.rp = r; |
201 |
greg |
1.1 |
/* get material color */ |
202 |
greg |
1.3 |
setcolor(nd.mcolor, m->oargs.farg[0], |
203 |
greg |
1.1 |
m->oargs.farg[1], |
204 |
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m->oargs.farg[2]); |
205 |
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/* get roughness */ |
206 |
greg |
2.2 |
nd.specfl = 0; |
207 |
greg |
1.3 |
nd.alpha2 = m->oargs.farg[4]; |
208 |
greg |
2.2 |
if ((nd.alpha2 *= nd.alpha2) <= FTINY) |
209 |
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nd.specfl |= SP_PURE; |
210 |
greg |
2.40 |
|
211 |
schorsch |
2.45 |
if ( (hastexture = (DOT(r->pert,r->pert) > FTINY*FTINY)) ) { |
212 |
greg |
2.29 |
nd.pdot = raynormal(nd.pnorm, r); /* perturb normal */ |
213 |
greg |
2.41 |
} else { |
214 |
greg |
2.29 |
VCOPY(nd.pnorm, r->ron); |
215 |
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nd.pdot = r->rod; |
216 |
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} |
217 |
greg |
2.42 |
if (r->ro != NULL && isflat(r->ro->otype)) |
218 |
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nd.specfl |= SP_FLAT; |
219 |
greg |
1.13 |
if (nd.pdot < .001) |
220 |
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nd.pdot = .001; /* non-zero for dirnorm() */ |
221 |
greg |
1.3 |
multcolor(nd.mcolor, r->pcol); /* modify material color */ |
222 |
greg |
2.29 |
mirtest = transtest = 0; |
223 |
|
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mirdist = transdist = r->rot; |
224 |
greg |
2.30 |
nd.rspec = m->oargs.farg[3]; |
225 |
greg |
2.38 |
/* compute Fresnel approx. */ |
226 |
greg |
2.51 |
if (nd.specfl & SP_PURE && nd.rspec >= FRESTHRESH) { |
227 |
greg |
2.62 |
fest = FRESNE(nd.pdot); |
228 |
greg |
2.38 |
nd.rspec += fest*(1. - nd.rspec); |
229 |
|
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} else |
230 |
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fest = 0.; |
231 |
greg |
1.3 |
/* compute transmission */ |
232 |
greg |
1.1 |
if (m->otype == MAT_TRANS) { |
233 |
greg |
1.3 |
nd.trans = m->oargs.farg[5]*(1.0 - nd.rspec); |
234 |
|
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nd.tspec = nd.trans * m->oargs.farg[6]; |
235 |
|
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nd.tdiff = nd.trans - nd.tspec; |
236 |
greg |
2.2 |
if (nd.tspec > FTINY) { |
237 |
|
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nd.specfl |= SP_TRAN; |
238 |
greg |
2.5 |
/* check threshold */ |
239 |
greg |
2.25 |
if (!(nd.specfl & SP_PURE) && |
240 |
|
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specthresh >= nd.tspec-FTINY) |
241 |
greg |
2.5 |
nd.specfl |= SP_TBLT; |
242 |
greg |
2.29 |
if (!hastexture || r->crtype & SHADOW) { |
243 |
greg |
2.2 |
VCOPY(nd.prdir, r->rdir); |
244 |
|
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transtest = 2; |
245 |
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} else { |
246 |
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for (i = 0; i < 3; i++) /* perturb */ |
247 |
greg |
2.19 |
nd.prdir[i] = r->rdir[i] - r->pert[i]; |
248 |
greg |
2.7 |
if (DOT(nd.prdir, r->ron) < -FTINY) |
249 |
|
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normalize(nd.prdir); /* OK */ |
250 |
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else |
251 |
|
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VCOPY(nd.prdir, r->rdir); |
252 |
greg |
2.2 |
} |
253 |
greg |
1.14 |
} |
254 |
greg |
1.1 |
} else |
255 |
greg |
1.3 |
nd.tdiff = nd.tspec = nd.trans = 0.0; |
256 |
greg |
1.1 |
/* transmitted ray */ |
257 |
gregl |
2.36 |
if ((nd.specfl&(SP_TRAN|SP_PURE|SP_TBLT)) == (SP_TRAN|SP_PURE)) { |
258 |
greg |
1.3 |
RAY lr; |
259 |
greg |
2.50 |
copycolor(lr.rcoef, nd.mcolor); /* modified by color */ |
260 |
|
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scalecolor(lr.rcoef, nd.tspec); |
261 |
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if (rayorigin(&lr, TRANS, r, lr.rcoef) == 0) { |
262 |
greg |
1.14 |
VCOPY(lr.rdir, nd.prdir); |
263 |
greg |
1.1 |
rayvalue(&lr); |
264 |
greg |
2.50 |
multcolor(lr.rcol, lr.rcoef); |
265 |
greg |
1.1 |
addcolor(r->rcol, lr.rcol); |
266 |
greg |
1.9 |
transtest *= bright(lr.rcol); |
267 |
|
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transdist = r->rot + lr.rt; |
268 |
greg |
1.1 |
} |
269 |
greg |
2.11 |
} else |
270 |
|
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transtest = 0; |
271 |
greg |
2.2 |
|
272 |
greg |
2.29 |
if (r->crtype & SHADOW) { /* the rest is shadow */ |
273 |
|
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r->rt = transdist; |
274 |
greg |
2.27 |
return(1); |
275 |
greg |
2.30 |
} |
276 |
|
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/* get specular reflection */ |
277 |
|
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if (nd.rspec > FTINY) { |
278 |
|
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nd.specfl |= SP_REFL; |
279 |
|
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/* compute specular color */ |
280 |
greg |
2.38 |
if (m->otype != MAT_METAL) { |
281 |
|
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setcolor(nd.scolor, nd.rspec, nd.rspec, nd.rspec); |
282 |
|
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} else if (fest > FTINY) { |
283 |
|
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d = nd.rspec*(1. - fest); |
284 |
|
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for (i = 0; i < 3; i++) |
285 |
|
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nd.scolor[i] = fest + nd.mcolor[i]*d; |
286 |
|
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} else { |
287 |
greg |
2.30 |
copycolor(nd.scolor, nd.mcolor); |
288 |
greg |
2.38 |
scalecolor(nd.scolor, nd.rspec); |
289 |
|
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} |
290 |
greg |
2.30 |
/* check threshold */ |
291 |
|
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if (!(nd.specfl & SP_PURE) && specthresh >= nd.rspec-FTINY) |
292 |
|
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nd.specfl |= SP_RBLT; |
293 |
|
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/* compute reflected ray */ |
294 |
greg |
2.55 |
VSUM(nd.vrefl, r->rdir, nd.pnorm, 2.*nd.pdot); |
295 |
greg |
2.30 |
/* penetration? */ |
296 |
|
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if (hastexture && DOT(nd.vrefl, r->ron) <= FTINY) |
297 |
greg |
2.55 |
VSUM(nd.vrefl, r->rdir, r->ron, 2.*r->rod); |
298 |
greg |
2.53 |
checknorm(nd.vrefl); |
299 |
gregl |
2.36 |
} |
300 |
|
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/* reflected ray */ |
301 |
|
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if ((nd.specfl&(SP_REFL|SP_PURE|SP_RBLT)) == (SP_REFL|SP_PURE)) { |
302 |
|
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RAY lr; |
303 |
greg |
2.50 |
if (rayorigin(&lr, REFLECTED, r, nd.scolor) == 0) { |
304 |
gregl |
2.36 |
VCOPY(lr.rdir, nd.vrefl); |
305 |
|
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rayvalue(&lr); |
306 |
greg |
2.50 |
multcolor(lr.rcol, lr.rcoef); |
307 |
gregl |
2.36 |
addcolor(r->rcol, lr.rcol); |
308 |
|
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if (!hastexture && nd.specfl & SP_FLAT) { |
309 |
|
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mirtest = 2.*bright(lr.rcol); |
310 |
|
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mirdist = r->rot + lr.rt; |
311 |
greg |
2.30 |
} |
312 |
|
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} |
313 |
greg |
2.29 |
} |
314 |
greg |
1.1 |
/* diffuse reflection */ |
315 |
greg |
1.3 |
nd.rdiff = 1.0 - nd.trans - nd.rspec; |
316 |
greg |
1.1 |
|
317 |
greg |
2.2 |
if (nd.specfl & SP_PURE && nd.rdiff <= FTINY && nd.tdiff <= FTINY) |
318 |
greg |
2.27 |
return(1); /* 100% pure specular */ |
319 |
greg |
2.3 |
|
320 |
gregl |
2.36 |
if (!(nd.specfl & SP_PURE)) |
321 |
|
|
gaussamp(r, &nd); /* checks *BLT flags */ |
322 |
greg |
2.2 |
|
323 |
greg |
1.3 |
if (nd.rdiff > FTINY) { /* ambient from this side */ |
324 |
greg |
2.50 |
copycolor(ctmp, nd.mcolor); /* modified by material color */ |
325 |
greg |
2.61 |
scalecolor(ctmp, nd.rdiff); |
326 |
|
|
if (nd.specfl & SP_RBLT) /* add in specular as well? */ |
327 |
|
|
addcolor(ctmp, nd.scolor); |
328 |
greg |
2.50 |
multambient(ctmp, r, hastexture ? nd.pnorm : r->ron); |
329 |
greg |
1.2 |
addcolor(r->rcol, ctmp); /* add to returned color */ |
330 |
|
|
} |
331 |
greg |
1.3 |
if (nd.tdiff > FTINY) { /* ambient from other side */ |
332 |
greg |
2.50 |
copycolor(ctmp, nd.mcolor); /* modified by color */ |
333 |
|
|
if (nd.specfl & SP_TBLT) |
334 |
|
|
scalecolor(ctmp, nd.trans); |
335 |
|
|
else |
336 |
|
|
scalecolor(ctmp, nd.tdiff); |
337 |
greg |
1.1 |
flipsurface(r); |
338 |
greg |
2.32 |
if (hastexture) { |
339 |
|
|
FVECT bnorm; |
340 |
|
|
bnorm[0] = -nd.pnorm[0]; |
341 |
|
|
bnorm[1] = -nd.pnorm[1]; |
342 |
|
|
bnorm[2] = -nd.pnorm[2]; |
343 |
greg |
2.50 |
multambient(ctmp, r, bnorm); |
344 |
greg |
2.32 |
} else |
345 |
greg |
2.50 |
multambient(ctmp, r, r->ron); |
346 |
greg |
1.1 |
addcolor(r->rcol, ctmp); |
347 |
|
|
flipsurface(r); |
348 |
|
|
} |
349 |
greg |
1.3 |
/* add direct component */ |
350 |
|
|
direct(r, dirnorm, &nd); |
351 |
greg |
1.9 |
/* check distance */ |
352 |
greg |
2.29 |
d = bright(r->rcol); |
353 |
|
|
if (transtest > d) |
354 |
greg |
1.9 |
r->rt = transdist; |
355 |
greg |
2.29 |
else if (mirtest > d) |
356 |
|
|
r->rt = mirdist; |
357 |
greg |
2.27 |
|
358 |
|
|
return(1); |
359 |
greg |
2.2 |
} |
360 |
|
|
|
361 |
|
|
|
362 |
greg |
2.38 |
static void |
363 |
greg |
2.54 |
gaussamp( /* sample Gaussian specular */ |
364 |
schorsch |
2.47 |
RAY *r, |
365 |
greg |
2.62 |
NORMDAT *np |
366 |
schorsch |
2.47 |
) |
367 |
greg |
2.2 |
{ |
368 |
|
|
RAY sr; |
369 |
|
|
FVECT u, v, h; |
370 |
|
|
double rv[2]; |
371 |
|
|
double d, sinp, cosp; |
372 |
greg |
2.62 |
COLOR scol; |
373 |
greg |
2.58 |
int maxiter, ntrials, nstarget, nstaken; |
374 |
greg |
2.62 |
int i; |
375 |
greg |
2.13 |
/* quick test */ |
376 |
|
|
if ((np->specfl & (SP_REFL|SP_RBLT)) != SP_REFL && |
377 |
|
|
(np->specfl & (SP_TRAN|SP_TBLT)) != SP_TRAN) |
378 |
|
|
return; |
379 |
greg |
2.2 |
/* set up sample coordinates */ |
380 |
|
|
v[0] = v[1] = v[2] = 0.0; |
381 |
|
|
for (i = 0; i < 3; i++) |
382 |
|
|
if (np->pnorm[i] < 0.6 && np->pnorm[i] > -0.6) |
383 |
|
|
break; |
384 |
|
|
v[i] = 1.0; |
385 |
|
|
fcross(u, v, np->pnorm); |
386 |
|
|
normalize(u); |
387 |
|
|
fcross(v, np->pnorm, u); |
388 |
|
|
/* compute reflection */ |
389 |
greg |
2.5 |
if ((np->specfl & (SP_REFL|SP_RBLT)) == SP_REFL && |
390 |
greg |
2.50 |
rayorigin(&sr, SPECULAR, r, np->scolor) == 0) { |
391 |
greg |
2.58 |
nstarget = 1; |
392 |
greg |
2.55 |
if (specjitter > 1.5) { /* multiple samples? */ |
393 |
greg |
2.58 |
nstarget = specjitter*r->rweight + .5; |
394 |
|
|
if (sr.rweight <= minweight*nstarget) |
395 |
|
|
nstarget = sr.rweight/minweight; |
396 |
|
|
if (nstarget > 1) { |
397 |
|
|
d = 1./nstarget; |
398 |
|
|
scalecolor(sr.rcoef, d); |
399 |
greg |
2.56 |
sr.rweight *= d; |
400 |
greg |
2.55 |
} else |
401 |
greg |
2.58 |
nstarget = 1; |
402 |
greg |
2.55 |
} |
403 |
greg |
2.58 |
setcolor(scol, 0., 0., 0.); |
404 |
greg |
2.60 |
dimlist[ndims++] = (int)(size_t)np->mp; |
405 |
greg |
2.58 |
maxiter = MAXITER*nstarget; |
406 |
|
|
for (nstaken = ntrials = 0; nstaken < nstarget && |
407 |
|
|
ntrials < maxiter; ntrials++) { |
408 |
|
|
if (ntrials) |
409 |
greg |
2.34 |
d = frandom(); |
410 |
|
|
else |
411 |
|
|
d = urand(ilhash(dimlist,ndims)+samplendx); |
412 |
|
|
multisamp(rv, 2, d); |
413 |
|
|
d = 2.0*PI * rv[0]; |
414 |
gwlarson |
2.37 |
cosp = tcos(d); |
415 |
|
|
sinp = tsin(d); |
416 |
greg |
2.55 |
if ((0. <= specjitter) & (specjitter < 1.)) |
417 |
|
|
rv[1] = 1.0 - specjitter*rv[1]; |
418 |
greg |
2.34 |
if (rv[1] <= FTINY) |
419 |
|
|
d = 1.0; |
420 |
|
|
else |
421 |
|
|
d = sqrt( np->alpha2 * -log(rv[1]) ); |
422 |
|
|
for (i = 0; i < 3; i++) |
423 |
|
|
h[i] = np->pnorm[i] + d*(cosp*u[i] + sinp*v[i]); |
424 |
|
|
d = -2.0 * DOT(h, r->rdir) / (1.0 + d*d); |
425 |
greg |
2.55 |
VSUM(sr.rdir, r->rdir, h, d); |
426 |
greg |
2.58 |
/* sample rejection test */ |
427 |
|
|
if ((d = DOT(sr.rdir, r->ron)) <= FTINY) |
428 |
greg |
2.55 |
continue; |
429 |
|
|
checknorm(sr.rdir); |
430 |
greg |
2.58 |
if (nstarget > 1) { /* W-G-M-D adjustment */ |
431 |
greg |
2.59 |
if (nstaken) rayclear(&sr); |
432 |
greg |
2.58 |
rayvalue(&sr); |
433 |
|
|
d = 2./(1. + r->rod/d); |
434 |
|
|
scalecolor(sr.rcol, d); |
435 |
|
|
addcolor(scol, sr.rcol); |
436 |
|
|
} else { |
437 |
|
|
rayvalue(&sr); |
438 |
|
|
multcolor(sr.rcol, sr.rcoef); |
439 |
|
|
addcolor(r->rcol, sr.rcol); |
440 |
greg |
2.34 |
} |
441 |
greg |
2.58 |
++nstaken; |
442 |
|
|
} |
443 |
|
|
if (nstarget > 1) { /* final W-G-M-D weighting */ |
444 |
|
|
multcolor(scol, sr.rcoef); |
445 |
|
|
d = (double)nstarget/ntrials; |
446 |
|
|
scalecolor(scol, d); |
447 |
|
|
addcolor(r->rcol, scol); |
448 |
greg |
2.34 |
} |
449 |
greg |
2.2 |
ndims--; |
450 |
|
|
} |
451 |
|
|
/* compute transmission */ |
452 |
greg |
2.50 |
copycolor(sr.rcoef, np->mcolor); /* modified by color */ |
453 |
|
|
scalecolor(sr.rcoef, np->tspec); |
454 |
greg |
2.8 |
if ((np->specfl & (SP_TRAN|SP_TBLT)) == SP_TRAN && |
455 |
greg |
2.50 |
rayorigin(&sr, SPECULAR, r, sr.rcoef) == 0) { |
456 |
greg |
2.58 |
nstarget = 1; |
457 |
greg |
2.55 |
if (specjitter > 1.5) { /* multiple samples? */ |
458 |
greg |
2.58 |
nstarget = specjitter*r->rweight + .5; |
459 |
|
|
if (sr.rweight <= minweight*nstarget) |
460 |
|
|
nstarget = sr.rweight/minweight; |
461 |
|
|
if (nstarget > 1) { |
462 |
|
|
d = 1./nstarget; |
463 |
greg |
2.56 |
scalecolor(sr.rcoef, d); |
464 |
|
|
sr.rweight *= d; |
465 |
greg |
2.55 |
} else |
466 |
greg |
2.58 |
nstarget = 1; |
467 |
greg |
2.55 |
} |
468 |
greg |
2.60 |
dimlist[ndims++] = (int)(size_t)np->mp; |
469 |
greg |
2.58 |
maxiter = MAXITER*nstarget; |
470 |
|
|
for (nstaken = ntrials = 0; nstaken < nstarget && |
471 |
|
|
ntrials < maxiter; ntrials++) { |
472 |
|
|
if (ntrials) |
473 |
greg |
2.34 |
d = frandom(); |
474 |
|
|
else |
475 |
greg |
2.58 |
d = urand(ilhash(dimlist,ndims)+samplendx); |
476 |
greg |
2.34 |
multisamp(rv, 2, d); |
477 |
|
|
d = 2.0*PI * rv[0]; |
478 |
gwlarson |
2.37 |
cosp = tcos(d); |
479 |
|
|
sinp = tsin(d); |
480 |
greg |
2.55 |
if ((0. <= specjitter) & (specjitter < 1.)) |
481 |
|
|
rv[1] = 1.0 - specjitter*rv[1]; |
482 |
greg |
2.34 |
if (rv[1] <= FTINY) |
483 |
|
|
d = 1.0; |
484 |
|
|
else |
485 |
gwlarson |
2.37 |
d = sqrt( np->alpha2 * -log(rv[1]) ); |
486 |
greg |
2.34 |
for (i = 0; i < 3; i++) |
487 |
|
|
sr.rdir[i] = np->prdir[i] + d*(cosp*u[i] + sinp*v[i]); |
488 |
greg |
2.58 |
/* sample rejection test */ |
489 |
greg |
2.55 |
if (DOT(sr.rdir, r->ron) >= -FTINY) |
490 |
|
|
continue; |
491 |
|
|
normalize(sr.rdir); /* OK, normalize */ |
492 |
greg |
2.59 |
if (nstaken) /* multi-sampling */ |
493 |
greg |
2.55 |
rayclear(&sr); |
494 |
|
|
rayvalue(&sr); |
495 |
|
|
multcolor(sr.rcol, sr.rcoef); |
496 |
|
|
addcolor(r->rcol, sr.rcol); |
497 |
greg |
2.58 |
++nstaken; |
498 |
greg |
2.34 |
} |
499 |
greg |
2.8 |
ndims--; |
500 |
|
|
} |
501 |
greg |
1.1 |
} |