1 |
greg |
2.1 |
#ifndef lint |
2 |
greg |
2.56 |
static const char RCSid[] = "$Id: aniso.c,v 2.55 2012/07/29 21:56:16 greg Exp $"; |
3 |
greg |
2.1 |
#endif |
4 |
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/* |
5 |
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* Shading functions for anisotropic materials. |
6 |
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*/ |
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8 |
greg |
2.35 |
#include "copyright.h" |
9 |
greg |
2.34 |
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10 |
greg |
2.1 |
#include "ray.h" |
11 |
greg |
2.40 |
#include "ambient.h" |
12 |
greg |
2.1 |
#include "otypes.h" |
13 |
schorsch |
2.41 |
#include "rtotypes.h" |
14 |
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#include "source.h" |
15 |
greg |
2.1 |
#include "func.h" |
16 |
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#include "random.h" |
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18 |
greg |
2.32 |
#ifndef MAXITER |
19 |
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#define MAXITER 10 /* maximum # specular ray attempts */ |
20 |
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#endif |
21 |
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22 |
greg |
2.1 |
/* |
23 |
greg |
2.22 |
* This routine implements the anisotropic Gaussian |
24 |
greg |
2.54 |
* model described by Ward in Siggraph `92 article, updated with |
25 |
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* normalization and sampling adjustments due to Geisler-Moroder and Duer. |
26 |
greg |
2.1 |
* We orient the surface towards the incoming ray, so a single |
27 |
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* surface can be used to represent an infinitely thin object. |
28 |
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* |
29 |
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* Arguments for MAT_PLASTIC2 and MAT_METAL2 are: |
30 |
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* 4+ ux uy uz funcfile [transform...] |
31 |
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* 0 |
32 |
greg |
2.54 |
* 6 red grn blu specular-frac. u-rough v-rough |
33 |
greg |
2.1 |
* |
34 |
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* Real arguments for MAT_TRANS2 are: |
35 |
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* 8 red grn blu rspec u-rough v-rough trans tspec |
36 |
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*/ |
37 |
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38 |
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/* specularity flags */ |
39 |
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#define SP_REFL 01 /* has reflected specular component */ |
40 |
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#define SP_TRAN 02 /* has transmitted specular */ |
41 |
greg |
2.10 |
#define SP_FLAT 04 /* reflecting surface is flat */ |
42 |
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#define SP_RBLT 010 /* reflection below sample threshold */ |
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#define SP_TBLT 020 /* transmission below threshold */ |
44 |
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#define SP_BADU 040 /* bad u direction calculation */ |
45 |
greg |
2.1 |
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46 |
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typedef struct { |
47 |
greg |
2.2 |
OBJREC *mp; /* material pointer */ |
48 |
greg |
2.1 |
RAY *rp; /* ray pointer */ |
49 |
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short specfl; /* specularity flags, defined above */ |
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COLOR mcolor; /* color of this material */ |
51 |
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COLOR scolor; /* color of specular component */ |
52 |
greg |
2.6 |
FVECT vrefl; /* vector in reflected direction */ |
53 |
greg |
2.1 |
FVECT prdir; /* vector in transmitted direction */ |
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FVECT u, v; /* u and v vectors orienting anisotropy */ |
55 |
greg |
2.18 |
double u_alpha; /* u roughness */ |
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double v_alpha; /* v roughness */ |
57 |
greg |
2.1 |
double rdiff, rspec; /* reflected specular, diffuse */ |
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double trans; /* transmissivity */ |
59 |
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double tdiff, tspec; /* transmitted specular, diffuse */ |
60 |
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FVECT pnorm; /* perturbed surface normal */ |
61 |
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double pdot; /* perturbed dot product */ |
62 |
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} ANISODAT; /* anisotropic material data */ |
63 |
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64 |
greg |
2.55 |
static void getacoords(ANISODAT *np); |
65 |
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static void agaussamp(ANISODAT *np); |
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greg |
2.34 |
|
67 |
greg |
2.1 |
|
68 |
greg |
2.34 |
static void |
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schorsch |
2.41 |
diraniso( /* compute source contribution */ |
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COLOR cval, /* returned coefficient */ |
71 |
greg |
2.54 |
void *nnp, /* material data */ |
72 |
schorsch |
2.41 |
FVECT ldir, /* light source direction */ |
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double omega /* light source size */ |
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) |
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greg |
2.1 |
{ |
76 |
greg |
2.54 |
ANISODAT *np = nnp; |
77 |
greg |
2.1 |
double ldot; |
78 |
greg |
2.16 |
double dtmp, dtmp1, dtmp2; |
79 |
greg |
2.1 |
FVECT h; |
80 |
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double au2, av2; |
81 |
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COLOR ctmp; |
82 |
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83 |
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setcolor(cval, 0.0, 0.0, 0.0); |
84 |
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85 |
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ldot = DOT(np->pnorm, ldir); |
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87 |
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if (ldot < 0.0 ? np->trans <= FTINY : np->trans >= 1.0-FTINY) |
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return; /* wrong side */ |
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90 |
greg |
2.54 |
if ((ldot > FTINY) & (np->rdiff > FTINY)) { |
91 |
greg |
2.1 |
/* |
92 |
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* Compute and add diffuse reflected component to returned |
93 |
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* color. The diffuse reflected component will always be |
94 |
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* modified by the color of the material. |
95 |
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*/ |
96 |
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copycolor(ctmp, np->mcolor); |
97 |
greg |
2.42 |
dtmp = ldot * omega * np->rdiff * (1.0/PI); |
98 |
greg |
2.1 |
scalecolor(ctmp, dtmp); |
99 |
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addcolor(cval, ctmp); |
100 |
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} |
101 |
greg |
2.10 |
if (ldot > FTINY && (np->specfl&(SP_REFL|SP_BADU)) == SP_REFL) { |
102 |
greg |
2.1 |
/* |
103 |
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* Compute specular reflection coefficient using |
104 |
greg |
2.46 |
* anisotropic Gaussian distribution model. |
105 |
greg |
2.1 |
*/ |
106 |
greg |
2.2 |
/* add source width if flat */ |
107 |
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if (np->specfl & SP_FLAT) |
108 |
greg |
2.42 |
au2 = av2 = omega * (0.25/PI); |
109 |
greg |
2.2 |
else |
110 |
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au2 = av2 = 0.0; |
111 |
greg |
2.18 |
au2 += np->u_alpha*np->u_alpha; |
112 |
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av2 += np->v_alpha*np->v_alpha; |
113 |
greg |
2.1 |
/* half vector */ |
114 |
greg |
2.54 |
VSUB(h, ldir, np->rp->rdir); |
115 |
greg |
2.1 |
/* ellipse */ |
116 |
greg |
2.16 |
dtmp1 = DOT(np->u, h); |
117 |
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dtmp1 *= dtmp1 / au2; |
118 |
greg |
2.1 |
dtmp2 = DOT(np->v, h); |
119 |
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dtmp2 *= dtmp2 / av2; |
120 |
greg |
2.46 |
/* new W-G-M-D model */ |
121 |
greg |
2.23 |
dtmp = DOT(np->pnorm, h); |
122 |
greg |
2.46 |
dtmp *= dtmp; |
123 |
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dtmp1 = (dtmp1 + dtmp2) / dtmp; |
124 |
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dtmp = exp(-dtmp1) * DOT(h,h) / |
125 |
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(PI * dtmp*dtmp * sqrt(au2*av2)); |
126 |
greg |
2.1 |
/* worth using? */ |
127 |
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if (dtmp > FTINY) { |
128 |
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copycolor(ctmp, np->scolor); |
129 |
greg |
2.46 |
dtmp *= ldot * omega; |
130 |
greg |
2.1 |
scalecolor(ctmp, dtmp); |
131 |
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addcolor(cval, ctmp); |
132 |
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} |
133 |
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} |
134 |
greg |
2.54 |
if ((ldot < -FTINY) & (np->tdiff > FTINY)) { |
135 |
greg |
2.1 |
/* |
136 |
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* Compute diffuse transmission. |
137 |
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*/ |
138 |
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copycolor(ctmp, np->mcolor); |
139 |
greg |
2.42 |
dtmp = -ldot * omega * np->tdiff * (1.0/PI); |
140 |
greg |
2.1 |
scalecolor(ctmp, dtmp); |
141 |
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addcolor(cval, ctmp); |
142 |
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} |
143 |
greg |
2.10 |
if (ldot < -FTINY && (np->specfl&(SP_TRAN|SP_BADU)) == SP_TRAN) { |
144 |
greg |
2.1 |
/* |
145 |
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* Compute specular transmission. Specular transmission |
146 |
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* is always modified by material color. |
147 |
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*/ |
148 |
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/* roughness + source */ |
149 |
greg |
2.42 |
au2 = av2 = omega * (1.0/PI); |
150 |
greg |
2.18 |
au2 += np->u_alpha*np->u_alpha; |
151 |
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av2 += np->v_alpha*np->v_alpha; |
152 |
greg |
2.16 |
/* "half vector" */ |
153 |
greg |
2.54 |
VSUB(h, ldir, np->prdir); |
154 |
greg |
2.19 |
dtmp = DOT(h,h); |
155 |
greg |
2.16 |
if (dtmp > FTINY*FTINY) { |
156 |
greg |
2.19 |
dtmp1 = DOT(h,np->pnorm); |
157 |
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dtmp = 1.0 - dtmp1*dtmp1/dtmp; |
158 |
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if (dtmp > FTINY*FTINY) { |
159 |
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dtmp1 = DOT(h,np->u); |
160 |
greg |
2.23 |
dtmp1 *= dtmp1 / au2; |
161 |
greg |
2.19 |
dtmp2 = DOT(h,np->v); |
162 |
greg |
2.23 |
dtmp2 *= dtmp2 / av2; |
163 |
greg |
2.19 |
dtmp = (dtmp1 + dtmp2) / dtmp; |
164 |
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} |
165 |
greg |
2.16 |
} else |
166 |
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dtmp = 0.0; |
167 |
greg |
2.46 |
/* Gaussian */ |
168 |
greg |
2.44 |
dtmp = exp(-dtmp) * (1.0/PI) * sqrt(-ldot/(np->pdot*au2*av2)); |
169 |
greg |
2.1 |
/* worth using? */ |
170 |
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if (dtmp > FTINY) { |
171 |
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copycolor(ctmp, np->mcolor); |
172 |
greg |
2.16 |
dtmp *= np->tspec * omega; |
173 |
greg |
2.1 |
scalecolor(ctmp, dtmp); |
174 |
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addcolor(cval, ctmp); |
175 |
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} |
176 |
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} |
177 |
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} |
178 |
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179 |
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180 |
greg |
2.54 |
int |
181 |
schorsch |
2.41 |
m_aniso( /* shade ray that hit something anisotropic */ |
182 |
greg |
2.54 |
OBJREC *m, |
183 |
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RAY *r |
184 |
schorsch |
2.41 |
) |
185 |
greg |
2.1 |
{ |
186 |
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ANISODAT nd; |
187 |
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COLOR ctmp; |
188 |
greg |
2.54 |
int i; |
189 |
greg |
2.1 |
/* easy shadow test */ |
190 |
greg |
2.10 |
if (r->crtype & SHADOW) |
191 |
greg |
2.27 |
return(1); |
192 |
greg |
2.1 |
|
193 |
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if (m->oargs.nfargs != (m->otype == MAT_TRANS2 ? 8 : 6)) |
194 |
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objerror(m, USER, "bad number of real arguments"); |
195 |
greg |
2.36 |
/* check for back side */ |
196 |
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if (r->rod < 0.0) { |
197 |
greg |
2.56 |
if (!backvis) { |
198 |
greg |
2.36 |
raytrans(r); |
199 |
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return(1); |
200 |
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} |
201 |
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raytexture(r, m->omod); |
202 |
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flipsurface(r); /* reorient if backvis */ |
203 |
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} else |
204 |
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raytexture(r, m->omod); |
205 |
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/* get material color */ |
206 |
greg |
2.2 |
nd.mp = m; |
207 |
greg |
2.1 |
nd.rp = r; |
208 |
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setcolor(nd.mcolor, m->oargs.farg[0], |
209 |
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m->oargs.farg[1], |
210 |
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m->oargs.farg[2]); |
211 |
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/* get roughness */ |
212 |
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nd.specfl = 0; |
213 |
greg |
2.18 |
nd.u_alpha = m->oargs.farg[4]; |
214 |
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nd.v_alpha = m->oargs.farg[5]; |
215 |
greg |
2.54 |
if ((nd.u_alpha <= FTINY) | (nd.v_alpha <= FTINY)) |
216 |
greg |
2.10 |
objerror(m, USER, "roughness too small"); |
217 |
greg |
2.36 |
|
218 |
greg |
2.1 |
nd.pdot = raynormal(nd.pnorm, r); /* perturb normal */ |
219 |
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if (nd.pdot < .001) |
220 |
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nd.pdot = .001; /* non-zero for diraniso() */ |
221 |
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multcolor(nd.mcolor, r->pcol); /* modify material color */ |
222 |
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/* get specular component */ |
223 |
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if ((nd.rspec = m->oargs.farg[3]) > FTINY) { |
224 |
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nd.specfl |= SP_REFL; |
225 |
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/* compute specular color */ |
226 |
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if (m->otype == MAT_METAL2) |
227 |
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copycolor(nd.scolor, nd.mcolor); |
228 |
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else |
229 |
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setcolor(nd.scolor, 1.0, 1.0, 1.0); |
230 |
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scalecolor(nd.scolor, nd.rspec); |
231 |
greg |
2.4 |
/* check threshold */ |
232 |
greg |
2.25 |
if (specthresh >= nd.rspec-FTINY) |
233 |
greg |
2.4 |
nd.specfl |= SP_RBLT; |
234 |
greg |
2.6 |
/* compute refl. direction */ |
235 |
greg |
2.47 |
VSUM(nd.vrefl, r->rdir, nd.pnorm, 2.0*nd.pdot); |
236 |
greg |
2.6 |
if (DOT(nd.vrefl, r->ron) <= FTINY) /* penetration? */ |
237 |
greg |
2.47 |
VSUM(nd.vrefl, r->rdir, r->ron, 2.0*r->rod); |
238 |
greg |
2.1 |
} |
239 |
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/* compute transmission */ |
240 |
greg |
2.16 |
if (m->otype == MAT_TRANS2) { |
241 |
greg |
2.1 |
nd.trans = m->oargs.farg[6]*(1.0 - nd.rspec); |
242 |
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nd.tspec = nd.trans * m->oargs.farg[7]; |
243 |
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nd.tdiff = nd.trans - nd.tspec; |
244 |
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if (nd.tspec > FTINY) { |
245 |
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nd.specfl |= SP_TRAN; |
246 |
greg |
2.4 |
/* check threshold */ |
247 |
greg |
2.25 |
if (specthresh >= nd.tspec-FTINY) |
248 |
greg |
2.4 |
nd.specfl |= SP_TBLT; |
249 |
greg |
2.10 |
if (DOT(r->pert,r->pert) <= FTINY*FTINY) { |
250 |
greg |
2.1 |
VCOPY(nd.prdir, r->rdir); |
251 |
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} else { |
252 |
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for (i = 0; i < 3; i++) /* perturb */ |
253 |
greg |
2.17 |
nd.prdir[i] = r->rdir[i] - r->pert[i]; |
254 |
greg |
2.6 |
if (DOT(nd.prdir, r->ron) < -FTINY) |
255 |
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normalize(nd.prdir); /* OK */ |
256 |
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else |
257 |
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VCOPY(nd.prdir, r->rdir); |
258 |
greg |
2.1 |
} |
259 |
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} |
260 |
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} else |
261 |
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nd.tdiff = nd.tspec = nd.trans = 0.0; |
262 |
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263 |
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/* diffuse reflection */ |
264 |
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nd.rdiff = 1.0 - nd.trans - nd.rspec; |
265 |
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|
266 |
greg |
2.39 |
if (r->ro != NULL && isflat(r->ro->otype)) |
267 |
greg |
2.4 |
nd.specfl |= SP_FLAT; |
268 |
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|
269 |
greg |
2.55 |
getacoords(&nd); /* set up coordinates */ |
270 |
greg |
2.1 |
|
271 |
greg |
2.10 |
if (nd.specfl & (SP_REFL|SP_TRAN) && !(nd.specfl & SP_BADU)) |
272 |
greg |
2.55 |
agaussamp(&nd); |
273 |
greg |
2.1 |
|
274 |
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if (nd.rdiff > FTINY) { /* ambient from this side */ |
275 |
greg |
2.43 |
copycolor(ctmp, nd.mcolor); /* modified by material color */ |
276 |
greg |
2.52 |
scalecolor(ctmp, nd.rdiff); |
277 |
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if (nd.specfl & SP_RBLT) /* add in specular as well? */ |
278 |
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addcolor(ctmp, nd.scolor); |
279 |
greg |
2.43 |
multambient(ctmp, r, nd.pnorm); |
280 |
greg |
2.1 |
addcolor(r->rcol, ctmp); /* add to returned color */ |
281 |
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} |
282 |
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if (nd.tdiff > FTINY) { /* ambient from other side */ |
283 |
greg |
2.31 |
FVECT bnorm; |
284 |
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|
285 |
greg |
2.1 |
flipsurface(r); |
286 |
greg |
2.31 |
bnorm[0] = -nd.pnorm[0]; |
287 |
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bnorm[1] = -nd.pnorm[1]; |
288 |
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bnorm[2] = -nd.pnorm[2]; |
289 |
greg |
2.43 |
copycolor(ctmp, nd.mcolor); /* modified by color */ |
290 |
greg |
2.4 |
if (nd.specfl & SP_TBLT) |
291 |
|
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scalecolor(ctmp, nd.trans); |
292 |
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else |
293 |
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scalecolor(ctmp, nd.tdiff); |
294 |
greg |
2.43 |
multambient(ctmp, r, bnorm); |
295 |
greg |
2.1 |
addcolor(r->rcol, ctmp); |
296 |
|
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flipsurface(r); |
297 |
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} |
298 |
|
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/* add direct component */ |
299 |
|
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direct(r, diraniso, &nd); |
300 |
greg |
2.27 |
|
301 |
|
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return(1); |
302 |
greg |
2.1 |
} |
303 |
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|
304 |
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|
305 |
greg |
2.34 |
static void |
306 |
schorsch |
2.41 |
getacoords( /* set up coordinate system */ |
307 |
greg |
2.54 |
ANISODAT *np |
308 |
schorsch |
2.41 |
) |
309 |
greg |
2.1 |
{ |
310 |
greg |
2.54 |
MFUNC *mf; |
311 |
|
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int i; |
312 |
greg |
2.1 |
|
313 |
|
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mf = getfunc(np->mp, 3, 0x7, 1); |
314 |
greg |
2.55 |
setfunc(np->mp, np->rp); |
315 |
greg |
2.1 |
errno = 0; |
316 |
|
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for (i = 0; i < 3; i++) |
317 |
|
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np->u[i] = evalue(mf->ep[i]); |
318 |
greg |
2.54 |
if ((errno == EDOM) | (errno == ERANGE)) { |
319 |
greg |
2.1 |
objerror(np->mp, WARNING, "compute error"); |
320 |
|
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np->specfl |= SP_BADU; |
321 |
|
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return; |
322 |
|
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} |
323 |
greg |
2.53 |
if (mf->fxp != &unitxf) |
324 |
|
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multv3(np->u, np->u, mf->fxp->xfm); |
325 |
greg |
2.1 |
fcross(np->v, np->pnorm, np->u); |
326 |
|
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if (normalize(np->v) == 0.0) { |
327 |
|
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objerror(np->mp, WARNING, "illegal orientation vector"); |
328 |
|
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np->specfl |= SP_BADU; |
329 |
|
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return; |
330 |
|
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} |
331 |
|
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fcross(np->u, np->v, np->pnorm); |
332 |
|
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} |
333 |
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|
334 |
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|
335 |
greg |
2.34 |
static void |
336 |
greg |
2.46 |
agaussamp( /* sample anisotropic Gaussian specular */ |
337 |
greg |
2.54 |
ANISODAT *np |
338 |
schorsch |
2.41 |
) |
339 |
greg |
2.1 |
{ |
340 |
|
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RAY sr; |
341 |
|
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FVECT h; |
342 |
|
|
double rv[2]; |
343 |
|
|
double d, sinp, cosp; |
344 |
greg |
2.47 |
COLOR scol; |
345 |
greg |
2.50 |
int maxiter, ntrials, nstarget, nstaken; |
346 |
greg |
2.54 |
int i; |
347 |
greg |
2.1 |
/* compute reflection */ |
348 |
greg |
2.4 |
if ((np->specfl & (SP_REFL|SP_RBLT)) == SP_REFL && |
349 |
greg |
2.55 |
rayorigin(&sr, SPECULAR, np->rp, np->scolor) == 0) { |
350 |
greg |
2.50 |
nstarget = 1; |
351 |
greg |
2.47 |
if (specjitter > 1.5) { /* multiple samples? */ |
352 |
greg |
2.55 |
nstarget = specjitter*np->rp->rweight + .5; |
353 |
greg |
2.50 |
if (sr.rweight <= minweight*nstarget) |
354 |
|
|
nstarget = sr.rweight/minweight; |
355 |
|
|
if (nstarget > 1) { |
356 |
|
|
d = 1./nstarget; |
357 |
|
|
scalecolor(sr.rcoef, d); |
358 |
greg |
2.48 |
sr.rweight *= d; |
359 |
greg |
2.47 |
} else |
360 |
greg |
2.50 |
nstarget = 1; |
361 |
greg |
2.47 |
} |
362 |
greg |
2.50 |
setcolor(scol, 0., 0., 0.); |
363 |
greg |
2.51 |
dimlist[ndims++] = (int)(size_t)np->mp; |
364 |
greg |
2.50 |
maxiter = MAXITER*nstarget; |
365 |
|
|
for (nstaken = ntrials = 0; nstaken < nstarget && |
366 |
|
|
ntrials < maxiter; ntrials++) { |
367 |
|
|
if (ntrials) |
368 |
greg |
2.32 |
d = frandom(); |
369 |
|
|
else |
370 |
|
|
d = urand(ilhash(dimlist,ndims)+samplendx); |
371 |
|
|
multisamp(rv, 2, d); |
372 |
|
|
d = 2.0*PI * rv[0]; |
373 |
gwlarson |
2.33 |
cosp = tcos(d) * np->u_alpha; |
374 |
|
|
sinp = tsin(d) * np->v_alpha; |
375 |
greg |
2.47 |
d = 1./sqrt(cosp*cosp + sinp*sinp); |
376 |
|
|
cosp *= d; |
377 |
|
|
sinp *= d; |
378 |
|
|
if ((0. <= specjitter) & (specjitter < 1.)) |
379 |
|
|
rv[1] = 1.0 - specjitter*rv[1]; |
380 |
greg |
2.32 |
if (rv[1] <= FTINY) |
381 |
|
|
d = 1.0; |
382 |
|
|
else |
383 |
|
|
d = sqrt(-log(rv[1]) / |
384 |
|
|
(cosp*cosp/(np->u_alpha*np->u_alpha) + |
385 |
|
|
sinp*sinp/(np->v_alpha*np->v_alpha))); |
386 |
|
|
for (i = 0; i < 3; i++) |
387 |
|
|
h[i] = np->pnorm[i] + |
388 |
|
|
d*(cosp*np->u[i] + sinp*np->v[i]); |
389 |
greg |
2.55 |
d = -2.0 * DOT(h, np->rp->rdir) / (1.0 + d*d); |
390 |
|
|
VSUM(sr.rdir, np->rp->rdir, h, d); |
391 |
greg |
2.50 |
/* sample rejection test */ |
392 |
greg |
2.55 |
if ((d = DOT(sr.rdir, np->rp->ron)) <= FTINY) |
393 |
greg |
2.47 |
continue; |
394 |
|
|
checknorm(sr.rdir); |
395 |
greg |
2.50 |
if (nstarget > 1) { /* W-G-M-D adjustment */ |
396 |
|
|
if (nstaken) rayclear(&sr); |
397 |
|
|
rayvalue(&sr); |
398 |
greg |
2.55 |
d = 2./(1. + np->rp->rod/d); |
399 |
greg |
2.50 |
scalecolor(sr.rcol, d); |
400 |
|
|
addcolor(scol, sr.rcol); |
401 |
|
|
} else { |
402 |
|
|
rayvalue(&sr); |
403 |
|
|
multcolor(sr.rcol, sr.rcoef); |
404 |
greg |
2.55 |
addcolor(np->rp->rcol, sr.rcol); |
405 |
greg |
2.32 |
} |
406 |
greg |
2.50 |
++nstaken; |
407 |
|
|
} |
408 |
|
|
if (nstarget > 1) { /* final W-G-M-D weighting */ |
409 |
|
|
multcolor(scol, sr.rcoef); |
410 |
|
|
d = (double)nstarget/ntrials; |
411 |
|
|
scalecolor(scol, d); |
412 |
greg |
2.55 |
addcolor(np->rp->rcol, scol); |
413 |
greg |
2.32 |
} |
414 |
greg |
2.1 |
ndims--; |
415 |
|
|
} |
416 |
|
|
/* compute transmission */ |
417 |
greg |
2.43 |
copycolor(sr.rcoef, np->mcolor); /* modify by material color */ |
418 |
|
|
scalecolor(sr.rcoef, np->tspec); |
419 |
greg |
2.7 |
if ((np->specfl & (SP_TRAN|SP_TBLT)) == SP_TRAN && |
420 |
greg |
2.55 |
rayorigin(&sr, SPECULAR, np->rp, sr.rcoef) == 0) { |
421 |
greg |
2.50 |
nstarget = 1; |
422 |
greg |
2.47 |
if (specjitter > 1.5) { /* multiple samples? */ |
423 |
greg |
2.55 |
nstarget = specjitter*np->rp->rweight + .5; |
424 |
greg |
2.50 |
if (sr.rweight <= minweight*nstarget) |
425 |
|
|
nstarget = sr.rweight/minweight; |
426 |
|
|
if (nstarget > 1) { |
427 |
|
|
d = 1./nstarget; |
428 |
greg |
2.48 |
scalecolor(sr.rcoef, d); |
429 |
|
|
sr.rweight *= d; |
430 |
greg |
2.47 |
} else |
431 |
greg |
2.50 |
nstarget = 1; |
432 |
greg |
2.47 |
} |
433 |
greg |
2.51 |
dimlist[ndims++] = (int)(size_t)np->mp; |
434 |
greg |
2.50 |
maxiter = MAXITER*nstarget; |
435 |
|
|
for (nstaken = ntrials = 0; nstaken < nstarget && |
436 |
|
|
ntrials < maxiter; ntrials++) { |
437 |
|
|
if (ntrials) |
438 |
greg |
2.32 |
d = frandom(); |
439 |
|
|
else |
440 |
|
|
d = urand(ilhash(dimlist,ndims)+1823+samplendx); |
441 |
|
|
multisamp(rv, 2, d); |
442 |
|
|
d = 2.0*PI * rv[0]; |
443 |
gwlarson |
2.33 |
cosp = tcos(d) * np->u_alpha; |
444 |
|
|
sinp = tsin(d) * np->v_alpha; |
445 |
greg |
2.47 |
d = 1./sqrt(cosp*cosp + sinp*sinp); |
446 |
|
|
cosp *= d; |
447 |
|
|
sinp *= d; |
448 |
|
|
if ((0. <= specjitter) & (specjitter < 1.)) |
449 |
|
|
rv[1] = 1.0 - specjitter*rv[1]; |
450 |
greg |
2.32 |
if (rv[1] <= FTINY) |
451 |
|
|
d = 1.0; |
452 |
|
|
else |
453 |
|
|
d = sqrt(-log(rv[1]) / |
454 |
|
|
(cosp*cosp/(np->u_alpha*np->u_alpha) + |
455 |
gwlarson |
2.33 |
sinp*sinp/(np->v_alpha*np->v_alpha))); |
456 |
greg |
2.32 |
for (i = 0; i < 3; i++) |
457 |
|
|
sr.rdir[i] = np->prdir[i] + |
458 |
|
|
d*(cosp*np->u[i] + sinp*np->v[i]); |
459 |
greg |
2.55 |
if (DOT(sr.rdir, np->rp->ron) >= -FTINY) |
460 |
greg |
2.47 |
continue; |
461 |
|
|
normalize(sr.rdir); /* OK, normalize */ |
462 |
greg |
2.50 |
if (nstaken) /* multi-sampling */ |
463 |
greg |
2.47 |
rayclear(&sr); |
464 |
|
|
rayvalue(&sr); |
465 |
|
|
multcolor(sr.rcol, sr.rcoef); |
466 |
greg |
2.55 |
addcolor(np->rp->rcol, sr.rcol); |
467 |
greg |
2.50 |
++nstaken; |
468 |
greg |
2.32 |
} |
469 |
greg |
2.7 |
ndims--; |
470 |
|
|
} |
471 |
greg |
2.1 |
} |