1 |
greg |
1.1 |
#ifndef lint |
2 |
greg |
2.60 |
static const char RCSid[] = "$Id: normal.c,v 2.59 2010/10/13 15:29:02 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 srcdirf_t dirnorm; |
69 |
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static void gaussamp(RAY *r, NORMDAT *np); |
70 |
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|
71 |
greg |
1.3 |
|
72 |
greg |
2.38 |
static void |
73 |
schorsch |
2.47 |
dirnorm( /* compute source contribution */ |
74 |
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COLOR cval, /* returned coefficient */ |
75 |
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void *nnp, /* material data */ |
76 |
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FVECT ldir, /* light source direction */ |
77 |
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double omega /* light source size */ |
78 |
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) |
79 |
greg |
1.3 |
{ |
80 |
schorsch |
2.47 |
register NORMDAT *np = nnp; |
81 |
greg |
1.1 |
double ldot; |
82 |
greg |
2.49 |
double lrdiff, ltdiff; |
83 |
greg |
2.54 |
double dtmp, d2, d3, d4; |
84 |
greg |
2.16 |
FVECT vtmp; |
85 |
greg |
1.3 |
COLOR ctmp; |
86 |
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87 |
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setcolor(cval, 0.0, 0.0, 0.0); |
88 |
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89 |
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ldot = DOT(np->pnorm, ldir); |
90 |
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91 |
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if (ldot < 0.0 ? np->trans <= FTINY : np->trans >= 1.0-FTINY) |
92 |
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return; /* wrong side */ |
93 |
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94 |
greg |
2.38 |
/* Fresnel estimate */ |
95 |
greg |
2.49 |
lrdiff = np->rdiff; |
96 |
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ltdiff = np->tdiff; |
97 |
greg |
2.51 |
if (np->specfl & SP_PURE && np->rspec >= FRESTHRESH && |
98 |
greg |
2.49 |
(lrdiff > FTINY) | (ltdiff > FTINY)) { |
99 |
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dtmp = 1. - FRESNE(fabs(ldot)); |
100 |
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lrdiff *= dtmp; |
101 |
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ltdiff *= dtmp; |
102 |
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} |
103 |
greg |
2.38 |
|
104 |
greg |
2.49 |
if (ldot > FTINY && lrdiff > FTINY) { |
105 |
greg |
1.3 |
/* |
106 |
greg |
1.4 |
* Compute and add diffuse reflected component to returned |
107 |
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* color. The diffuse reflected component will always be |
108 |
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* modified by the color of the material. |
109 |
greg |
1.3 |
*/ |
110 |
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copycolor(ctmp, np->mcolor); |
111 |
greg |
2.49 |
dtmp = ldot * omega * lrdiff * (1.0/PI); |
112 |
greg |
1.3 |
scalecolor(ctmp, dtmp); |
113 |
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addcolor(cval, ctmp); |
114 |
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} |
115 |
greg |
2.2 |
if (ldot > FTINY && (np->specfl&(SP_REFL|SP_PURE)) == SP_REFL) { |
116 |
greg |
1.3 |
/* |
117 |
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* Compute specular reflection coefficient using |
118 |
greg |
2.54 |
* Gaussian distribution model. |
119 |
greg |
1.3 |
*/ |
120 |
greg |
2.3 |
/* roughness */ |
121 |
greg |
2.16 |
dtmp = np->alpha2; |
122 |
greg |
2.3 |
/* + source if flat */ |
123 |
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if (np->specfl & SP_FLAT) |
124 |
greg |
2.48 |
dtmp += omega * (0.25/PI); |
125 |
greg |
2.23 |
/* half vector */ |
126 |
greg |
2.18 |
vtmp[0] = ldir[0] - np->rp->rdir[0]; |
127 |
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vtmp[1] = ldir[1] - np->rp->rdir[1]; |
128 |
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vtmp[2] = ldir[2] - np->rp->rdir[2]; |
129 |
greg |
2.16 |
d2 = DOT(vtmp, np->pnorm); |
130 |
greg |
2.23 |
d2 *= d2; |
131 |
greg |
2.54 |
d3 = DOT(vtmp,vtmp); |
132 |
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d4 = (d3 - d2) / d2; |
133 |
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/* new W-G-M-D model */ |
134 |
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dtmp = exp(-d4/dtmp) * d3 / (PI * d2*d2 * dtmp); |
135 |
greg |
1.3 |
/* worth using? */ |
136 |
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if (dtmp > FTINY) { |
137 |
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copycolor(ctmp, np->scolor); |
138 |
greg |
2.54 |
dtmp *= ldot * omega; |
139 |
greg |
1.3 |
scalecolor(ctmp, dtmp); |
140 |
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addcolor(cval, ctmp); |
141 |
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} |
142 |
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} |
143 |
greg |
2.49 |
if (ldot < -FTINY && ltdiff > FTINY) { |
144 |
greg |
1.3 |
/* |
145 |
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* Compute diffuse transmission. |
146 |
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*/ |
147 |
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copycolor(ctmp, np->mcolor); |
148 |
greg |
2.49 |
dtmp = -ldot * omega * ltdiff * (1.0/PI); |
149 |
greg |
1.3 |
scalecolor(ctmp, dtmp); |
150 |
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addcolor(cval, ctmp); |
151 |
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} |
152 |
greg |
2.2 |
if (ldot < -FTINY && (np->specfl&(SP_TRAN|SP_PURE)) == SP_TRAN) { |
153 |
greg |
1.3 |
/* |
154 |
greg |
1.4 |
* Compute specular transmission. Specular transmission |
155 |
greg |
1.13 |
* is always modified by material color. |
156 |
greg |
1.3 |
*/ |
157 |
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/* roughness + source */ |
158 |
greg |
2.48 |
dtmp = np->alpha2 + omega*(1.0/PI); |
159 |
greg |
2.54 |
/* Gaussian */ |
160 |
greg |
2.53 |
dtmp = exp((2.*DOT(np->prdir,ldir)-2.)/dtmp)/(PI*dtmp); |
161 |
greg |
1.3 |
/* worth using? */ |
162 |
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if (dtmp > FTINY) { |
163 |
greg |
1.13 |
copycolor(ctmp, np->mcolor); |
164 |
greg |
2.52 |
dtmp *= np->tspec * omega * sqrt(-ldot/np->pdot); |
165 |
greg |
1.13 |
scalecolor(ctmp, dtmp); |
166 |
greg |
1.3 |
addcolor(cval, ctmp); |
167 |
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} |
168 |
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} |
169 |
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} |
170 |
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171 |
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|
172 |
schorsch |
2.47 |
extern int |
173 |
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m_normal( /* color a ray that hit something normal */ |
174 |
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register OBJREC *m, |
175 |
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register RAY *r |
176 |
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) |
177 |
greg |
1.3 |
{ |
178 |
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NORMDAT nd; |
179 |
greg |
2.38 |
double fest; |
180 |
greg |
1.9 |
double transtest, transdist; |
181 |
greg |
2.29 |
double mirtest, mirdist; |
182 |
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int hastexture; |
183 |
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double d; |
184 |
greg |
1.1 |
COLOR ctmp; |
185 |
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register int i; |
186 |
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/* easy shadow test */ |
187 |
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if (r->crtype & SHADOW && m->otype != MAT_TRANS) |
188 |
greg |
2.27 |
return(1); |
189 |
greg |
2.2 |
|
190 |
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if (m->oargs.nfargs != (m->otype == MAT_TRANS ? 7 : 5)) |
191 |
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objerror(m, USER, "bad number of arguments"); |
192 |
greg |
2.29 |
/* check for back side */ |
193 |
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if (r->rod < 0.0) { |
194 |
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if (!backvis && m->otype != MAT_TRANS) { |
195 |
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raytrans(r); |
196 |
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return(1); |
197 |
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} |
198 |
greg |
2.40 |
raytexture(r, m->omod); |
199 |
greg |
2.29 |
flipsurface(r); /* reorient if backvis */ |
200 |
greg |
2.40 |
} else |
201 |
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raytexture(r, m->omod); |
202 |
greg |
1.3 |
nd.mp = m; |
203 |
greg |
2.16 |
nd.rp = r; |
204 |
greg |
1.1 |
/* get material color */ |
205 |
greg |
1.3 |
setcolor(nd.mcolor, m->oargs.farg[0], |
206 |
greg |
1.1 |
m->oargs.farg[1], |
207 |
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m->oargs.farg[2]); |
208 |
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/* get roughness */ |
209 |
greg |
2.2 |
nd.specfl = 0; |
210 |
greg |
1.3 |
nd.alpha2 = m->oargs.farg[4]; |
211 |
greg |
2.2 |
if ((nd.alpha2 *= nd.alpha2) <= FTINY) |
212 |
|
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nd.specfl |= SP_PURE; |
213 |
greg |
2.40 |
|
214 |
schorsch |
2.45 |
if ( (hastexture = (DOT(r->pert,r->pert) > FTINY*FTINY)) ) { |
215 |
greg |
2.29 |
nd.pdot = raynormal(nd.pnorm, r); /* perturb normal */ |
216 |
greg |
2.41 |
} else { |
217 |
greg |
2.29 |
VCOPY(nd.pnorm, r->ron); |
218 |
|
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nd.pdot = r->rod; |
219 |
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} |
220 |
greg |
2.42 |
if (r->ro != NULL && isflat(r->ro->otype)) |
221 |
|
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nd.specfl |= SP_FLAT; |
222 |
greg |
1.13 |
if (nd.pdot < .001) |
223 |
|
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nd.pdot = .001; /* non-zero for dirnorm() */ |
224 |
greg |
1.3 |
multcolor(nd.mcolor, r->pcol); /* modify material color */ |
225 |
greg |
2.29 |
mirtest = transtest = 0; |
226 |
|
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mirdist = transdist = r->rot; |
227 |
greg |
2.30 |
nd.rspec = m->oargs.farg[3]; |
228 |
greg |
2.38 |
/* compute Fresnel approx. */ |
229 |
greg |
2.51 |
if (nd.specfl & SP_PURE && nd.rspec >= FRESTHRESH) { |
230 |
greg |
2.38 |
fest = FRESNE(r->rod); |
231 |
|
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nd.rspec += fest*(1. - nd.rspec); |
232 |
|
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} else |
233 |
|
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fest = 0.; |
234 |
greg |
1.3 |
/* compute transmission */ |
235 |
greg |
1.1 |
if (m->otype == MAT_TRANS) { |
236 |
greg |
1.3 |
nd.trans = m->oargs.farg[5]*(1.0 - nd.rspec); |
237 |
|
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nd.tspec = nd.trans * m->oargs.farg[6]; |
238 |
|
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nd.tdiff = nd.trans - nd.tspec; |
239 |
greg |
2.2 |
if (nd.tspec > FTINY) { |
240 |
|
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nd.specfl |= SP_TRAN; |
241 |
greg |
2.5 |
/* check threshold */ |
242 |
greg |
2.25 |
if (!(nd.specfl & SP_PURE) && |
243 |
|
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specthresh >= nd.tspec-FTINY) |
244 |
greg |
2.5 |
nd.specfl |= SP_TBLT; |
245 |
greg |
2.29 |
if (!hastexture || r->crtype & SHADOW) { |
246 |
greg |
2.2 |
VCOPY(nd.prdir, r->rdir); |
247 |
|
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transtest = 2; |
248 |
|
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} else { |
249 |
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for (i = 0; i < 3; i++) /* perturb */ |
250 |
greg |
2.19 |
nd.prdir[i] = r->rdir[i] - r->pert[i]; |
251 |
greg |
2.7 |
if (DOT(nd.prdir, r->ron) < -FTINY) |
252 |
|
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normalize(nd.prdir); /* OK */ |
253 |
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else |
254 |
|
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VCOPY(nd.prdir, r->rdir); |
255 |
greg |
2.2 |
} |
256 |
greg |
1.14 |
} |
257 |
greg |
1.1 |
} else |
258 |
greg |
1.3 |
nd.tdiff = nd.tspec = nd.trans = 0.0; |
259 |
greg |
1.1 |
/* transmitted ray */ |
260 |
gregl |
2.36 |
if ((nd.specfl&(SP_TRAN|SP_PURE|SP_TBLT)) == (SP_TRAN|SP_PURE)) { |
261 |
greg |
1.3 |
RAY lr; |
262 |
greg |
2.50 |
copycolor(lr.rcoef, nd.mcolor); /* modified by color */ |
263 |
|
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scalecolor(lr.rcoef, nd.tspec); |
264 |
|
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if (rayorigin(&lr, TRANS, r, lr.rcoef) == 0) { |
265 |
greg |
1.14 |
VCOPY(lr.rdir, nd.prdir); |
266 |
greg |
1.1 |
rayvalue(&lr); |
267 |
greg |
2.50 |
multcolor(lr.rcol, lr.rcoef); |
268 |
greg |
1.1 |
addcolor(r->rcol, lr.rcol); |
269 |
greg |
1.9 |
transtest *= bright(lr.rcol); |
270 |
|
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transdist = r->rot + lr.rt; |
271 |
greg |
1.1 |
} |
272 |
greg |
2.11 |
} else |
273 |
|
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transtest = 0; |
274 |
greg |
2.2 |
|
275 |
greg |
2.29 |
if (r->crtype & SHADOW) { /* the rest is shadow */ |
276 |
|
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r->rt = transdist; |
277 |
greg |
2.27 |
return(1); |
278 |
greg |
2.30 |
} |
279 |
|
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/* get specular reflection */ |
280 |
|
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if (nd.rspec > FTINY) { |
281 |
|
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nd.specfl |= SP_REFL; |
282 |
|
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/* compute specular color */ |
283 |
greg |
2.38 |
if (m->otype != MAT_METAL) { |
284 |
|
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setcolor(nd.scolor, nd.rspec, nd.rspec, nd.rspec); |
285 |
|
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} else if (fest > FTINY) { |
286 |
|
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d = nd.rspec*(1. - fest); |
287 |
|
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for (i = 0; i < 3; i++) |
288 |
|
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nd.scolor[i] = fest + nd.mcolor[i]*d; |
289 |
|
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} else { |
290 |
greg |
2.30 |
copycolor(nd.scolor, nd.mcolor); |
291 |
greg |
2.38 |
scalecolor(nd.scolor, nd.rspec); |
292 |
|
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} |
293 |
greg |
2.30 |
/* check threshold */ |
294 |
|
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if (!(nd.specfl & SP_PURE) && specthresh >= nd.rspec-FTINY) |
295 |
|
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nd.specfl |= SP_RBLT; |
296 |
|
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/* compute reflected ray */ |
297 |
greg |
2.55 |
VSUM(nd.vrefl, r->rdir, nd.pnorm, 2.*nd.pdot); |
298 |
greg |
2.30 |
/* penetration? */ |
299 |
|
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if (hastexture && DOT(nd.vrefl, r->ron) <= FTINY) |
300 |
greg |
2.55 |
VSUM(nd.vrefl, r->rdir, r->ron, 2.*r->rod); |
301 |
greg |
2.53 |
checknorm(nd.vrefl); |
302 |
gregl |
2.36 |
} |
303 |
|
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/* reflected ray */ |
304 |
|
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if ((nd.specfl&(SP_REFL|SP_PURE|SP_RBLT)) == (SP_REFL|SP_PURE)) { |
305 |
|
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RAY lr; |
306 |
greg |
2.50 |
if (rayorigin(&lr, REFLECTED, r, nd.scolor) == 0) { |
307 |
gregl |
2.36 |
VCOPY(lr.rdir, nd.vrefl); |
308 |
|
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rayvalue(&lr); |
309 |
greg |
2.50 |
multcolor(lr.rcol, lr.rcoef); |
310 |
gregl |
2.36 |
addcolor(r->rcol, lr.rcol); |
311 |
|
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if (!hastexture && nd.specfl & SP_FLAT) { |
312 |
|
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mirtest = 2.*bright(lr.rcol); |
313 |
|
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mirdist = r->rot + lr.rt; |
314 |
greg |
2.30 |
} |
315 |
|
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} |
316 |
greg |
2.29 |
} |
317 |
greg |
1.1 |
/* diffuse reflection */ |
318 |
greg |
1.3 |
nd.rdiff = 1.0 - nd.trans - nd.rspec; |
319 |
greg |
1.1 |
|
320 |
greg |
2.2 |
if (nd.specfl & SP_PURE && nd.rdiff <= FTINY && nd.tdiff <= FTINY) |
321 |
greg |
2.27 |
return(1); /* 100% pure specular */ |
322 |
greg |
2.3 |
|
323 |
gregl |
2.36 |
if (!(nd.specfl & SP_PURE)) |
324 |
|
|
gaussamp(r, &nd); /* checks *BLT flags */ |
325 |
greg |
2.2 |
|
326 |
greg |
1.3 |
if (nd.rdiff > FTINY) { /* ambient from this side */ |
327 |
greg |
2.50 |
copycolor(ctmp, nd.mcolor); /* modified by material color */ |
328 |
greg |
2.5 |
if (nd.specfl & SP_RBLT) |
329 |
|
|
scalecolor(ctmp, 1.0-nd.trans); |
330 |
|
|
else |
331 |
|
|
scalecolor(ctmp, nd.rdiff); |
332 |
greg |
2.50 |
multambient(ctmp, r, hastexture ? nd.pnorm : r->ron); |
333 |
greg |
1.2 |
addcolor(r->rcol, ctmp); /* add to returned color */ |
334 |
|
|
} |
335 |
greg |
1.3 |
if (nd.tdiff > FTINY) { /* ambient from other side */ |
336 |
greg |
2.50 |
copycolor(ctmp, nd.mcolor); /* modified by color */ |
337 |
|
|
if (nd.specfl & SP_TBLT) |
338 |
|
|
scalecolor(ctmp, nd.trans); |
339 |
|
|
else |
340 |
|
|
scalecolor(ctmp, nd.tdiff); |
341 |
greg |
1.1 |
flipsurface(r); |
342 |
greg |
2.32 |
if (hastexture) { |
343 |
|
|
FVECT bnorm; |
344 |
|
|
bnorm[0] = -nd.pnorm[0]; |
345 |
|
|
bnorm[1] = -nd.pnorm[1]; |
346 |
|
|
bnorm[2] = -nd.pnorm[2]; |
347 |
greg |
2.50 |
multambient(ctmp, r, bnorm); |
348 |
greg |
2.32 |
} else |
349 |
greg |
2.50 |
multambient(ctmp, r, r->ron); |
350 |
greg |
1.1 |
addcolor(r->rcol, ctmp); |
351 |
|
|
flipsurface(r); |
352 |
|
|
} |
353 |
greg |
1.3 |
/* add direct component */ |
354 |
|
|
direct(r, dirnorm, &nd); |
355 |
greg |
1.9 |
/* check distance */ |
356 |
greg |
2.29 |
d = bright(r->rcol); |
357 |
|
|
if (transtest > d) |
358 |
greg |
1.9 |
r->rt = transdist; |
359 |
greg |
2.29 |
else if (mirtest > d) |
360 |
|
|
r->rt = mirdist; |
361 |
greg |
2.27 |
|
362 |
|
|
return(1); |
363 |
greg |
2.2 |
} |
364 |
|
|
|
365 |
|
|
|
366 |
greg |
2.38 |
static void |
367 |
greg |
2.54 |
gaussamp( /* sample Gaussian specular */ |
368 |
schorsch |
2.47 |
RAY *r, |
369 |
|
|
register NORMDAT *np |
370 |
|
|
) |
371 |
greg |
2.2 |
{ |
372 |
|
|
RAY sr; |
373 |
|
|
FVECT u, v, h; |
374 |
|
|
double rv[2]; |
375 |
|
|
double d, sinp, cosp; |
376 |
greg |
2.55 |
COLOR scol; |
377 |
greg |
2.58 |
int maxiter, ntrials, nstarget, nstaken; |
378 |
greg |
2.2 |
register int i; |
379 |
greg |
2.13 |
/* quick test */ |
380 |
|
|
if ((np->specfl & (SP_REFL|SP_RBLT)) != SP_REFL && |
381 |
|
|
(np->specfl & (SP_TRAN|SP_TBLT)) != SP_TRAN) |
382 |
|
|
return; |
383 |
greg |
2.2 |
/* set up sample coordinates */ |
384 |
|
|
v[0] = v[1] = v[2] = 0.0; |
385 |
|
|
for (i = 0; i < 3; i++) |
386 |
|
|
if (np->pnorm[i] < 0.6 && np->pnorm[i] > -0.6) |
387 |
|
|
break; |
388 |
|
|
v[i] = 1.0; |
389 |
|
|
fcross(u, v, np->pnorm); |
390 |
|
|
normalize(u); |
391 |
|
|
fcross(v, np->pnorm, u); |
392 |
|
|
/* compute reflection */ |
393 |
greg |
2.5 |
if ((np->specfl & (SP_REFL|SP_RBLT)) == SP_REFL && |
394 |
greg |
2.50 |
rayorigin(&sr, SPECULAR, r, np->scolor) == 0) { |
395 |
greg |
2.58 |
nstarget = 1; |
396 |
greg |
2.55 |
if (specjitter > 1.5) { /* multiple samples? */ |
397 |
greg |
2.58 |
nstarget = specjitter*r->rweight + .5; |
398 |
|
|
if (sr.rweight <= minweight*nstarget) |
399 |
|
|
nstarget = sr.rweight/minweight; |
400 |
|
|
if (nstarget > 1) { |
401 |
|
|
d = 1./nstarget; |
402 |
|
|
scalecolor(sr.rcoef, d); |
403 |
greg |
2.56 |
sr.rweight *= d; |
404 |
greg |
2.55 |
} else |
405 |
greg |
2.58 |
nstarget = 1; |
406 |
greg |
2.55 |
} |
407 |
greg |
2.58 |
setcolor(scol, 0., 0., 0.); |
408 |
greg |
2.60 |
dimlist[ndims++] = (int)(size_t)np->mp; |
409 |
greg |
2.58 |
maxiter = MAXITER*nstarget; |
410 |
|
|
for (nstaken = ntrials = 0; nstaken < nstarget && |
411 |
|
|
ntrials < maxiter; ntrials++) { |
412 |
|
|
if (ntrials) |
413 |
greg |
2.34 |
d = frandom(); |
414 |
|
|
else |
415 |
|
|
d = urand(ilhash(dimlist,ndims)+samplendx); |
416 |
|
|
multisamp(rv, 2, d); |
417 |
|
|
d = 2.0*PI * rv[0]; |
418 |
gwlarson |
2.37 |
cosp = tcos(d); |
419 |
|
|
sinp = tsin(d); |
420 |
greg |
2.55 |
if ((0. <= specjitter) & (specjitter < 1.)) |
421 |
|
|
rv[1] = 1.0 - specjitter*rv[1]; |
422 |
greg |
2.34 |
if (rv[1] <= FTINY) |
423 |
|
|
d = 1.0; |
424 |
|
|
else |
425 |
|
|
d = sqrt( np->alpha2 * -log(rv[1]) ); |
426 |
|
|
for (i = 0; i < 3; i++) |
427 |
|
|
h[i] = np->pnorm[i] + d*(cosp*u[i] + sinp*v[i]); |
428 |
|
|
d = -2.0 * DOT(h, r->rdir) / (1.0 + d*d); |
429 |
greg |
2.55 |
VSUM(sr.rdir, r->rdir, h, d); |
430 |
greg |
2.58 |
/* sample rejection test */ |
431 |
|
|
if ((d = DOT(sr.rdir, r->ron)) <= FTINY) |
432 |
greg |
2.55 |
continue; |
433 |
|
|
checknorm(sr.rdir); |
434 |
greg |
2.58 |
if (nstarget > 1) { /* W-G-M-D adjustment */ |
435 |
greg |
2.59 |
if (nstaken) rayclear(&sr); |
436 |
greg |
2.58 |
rayvalue(&sr); |
437 |
|
|
d = 2./(1. + r->rod/d); |
438 |
|
|
scalecolor(sr.rcol, d); |
439 |
|
|
addcolor(scol, sr.rcol); |
440 |
|
|
} else { |
441 |
|
|
rayvalue(&sr); |
442 |
|
|
multcolor(sr.rcol, sr.rcoef); |
443 |
|
|
addcolor(r->rcol, sr.rcol); |
444 |
greg |
2.34 |
} |
445 |
greg |
2.58 |
++nstaken; |
446 |
|
|
} |
447 |
|
|
if (nstarget > 1) { /* final W-G-M-D weighting */ |
448 |
|
|
multcolor(scol, sr.rcoef); |
449 |
|
|
d = (double)nstarget/ntrials; |
450 |
|
|
scalecolor(scol, d); |
451 |
|
|
addcolor(r->rcol, scol); |
452 |
greg |
2.34 |
} |
453 |
greg |
2.2 |
ndims--; |
454 |
|
|
} |
455 |
|
|
/* compute transmission */ |
456 |
greg |
2.50 |
copycolor(sr.rcoef, np->mcolor); /* modified by color */ |
457 |
|
|
scalecolor(sr.rcoef, np->tspec); |
458 |
greg |
2.8 |
if ((np->specfl & (SP_TRAN|SP_TBLT)) == SP_TRAN && |
459 |
greg |
2.50 |
rayorigin(&sr, SPECULAR, r, sr.rcoef) == 0) { |
460 |
greg |
2.58 |
nstarget = 1; |
461 |
greg |
2.55 |
if (specjitter > 1.5) { /* multiple samples? */ |
462 |
greg |
2.58 |
nstarget = specjitter*r->rweight + .5; |
463 |
|
|
if (sr.rweight <= minweight*nstarget) |
464 |
|
|
nstarget = sr.rweight/minweight; |
465 |
|
|
if (nstarget > 1) { |
466 |
|
|
d = 1./nstarget; |
467 |
greg |
2.56 |
scalecolor(sr.rcoef, d); |
468 |
|
|
sr.rweight *= d; |
469 |
greg |
2.55 |
} else |
470 |
greg |
2.58 |
nstarget = 1; |
471 |
greg |
2.55 |
} |
472 |
greg |
2.60 |
dimlist[ndims++] = (int)(size_t)np->mp; |
473 |
greg |
2.58 |
maxiter = MAXITER*nstarget; |
474 |
|
|
for (nstaken = ntrials = 0; nstaken < nstarget && |
475 |
|
|
ntrials < maxiter; ntrials++) { |
476 |
|
|
if (ntrials) |
477 |
greg |
2.34 |
d = frandom(); |
478 |
|
|
else |
479 |
greg |
2.58 |
d = urand(ilhash(dimlist,ndims)+samplendx); |
480 |
greg |
2.34 |
multisamp(rv, 2, d); |
481 |
|
|
d = 2.0*PI * rv[0]; |
482 |
gwlarson |
2.37 |
cosp = tcos(d); |
483 |
|
|
sinp = tsin(d); |
484 |
greg |
2.55 |
if ((0. <= specjitter) & (specjitter < 1.)) |
485 |
|
|
rv[1] = 1.0 - specjitter*rv[1]; |
486 |
greg |
2.34 |
if (rv[1] <= FTINY) |
487 |
|
|
d = 1.0; |
488 |
|
|
else |
489 |
gwlarson |
2.37 |
d = sqrt( np->alpha2 * -log(rv[1]) ); |
490 |
greg |
2.34 |
for (i = 0; i < 3; i++) |
491 |
|
|
sr.rdir[i] = np->prdir[i] + d*(cosp*u[i] + sinp*v[i]); |
492 |
greg |
2.58 |
/* sample rejection test */ |
493 |
greg |
2.55 |
if (DOT(sr.rdir, r->ron) >= -FTINY) |
494 |
|
|
continue; |
495 |
|
|
normalize(sr.rdir); /* OK, normalize */ |
496 |
greg |
2.59 |
if (nstaken) /* multi-sampling */ |
497 |
greg |
2.55 |
rayclear(&sr); |
498 |
|
|
rayvalue(&sr); |
499 |
|
|
multcolor(sr.rcol, sr.rcoef); |
500 |
|
|
addcolor(r->rcol, sr.rcol); |
501 |
greg |
2.58 |
++nstaken; |
502 |
greg |
2.34 |
} |
503 |
greg |
2.8 |
ndims--; |
504 |
|
|
} |
505 |
greg |
1.1 |
} |