1 |
greg |
1.25 |
/* Copyright (c) 1990 Regents of the University of California */ |
2 |
greg |
1.1 |
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3 |
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#ifndef lint |
4 |
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static char SCCSid[] = "$SunId$ LBL"; |
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#endif |
6 |
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7 |
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/* |
8 |
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* source.c - routines dealing with illumination sources. |
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* |
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* 8/20/85 |
11 |
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*/ |
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13 |
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#include "ray.h" |
14 |
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15 |
greg |
1.4 |
#include "octree.h" |
16 |
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17 |
greg |
1.1 |
#include "source.h" |
18 |
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19 |
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#include "otypes.h" |
20 |
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21 |
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#include "cone.h" |
22 |
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23 |
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#include "face.h" |
24 |
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25 |
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#include "random.h" |
26 |
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27 |
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28 |
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extern double dstrsrc; /* source distribution amount */ |
29 |
greg |
1.4 |
extern double shadthresh; /* relative shadow threshold */ |
30 |
greg |
1.12 |
extern double shadcert; /* shadow testing certainty */ |
31 |
greg |
1.1 |
|
32 |
greg |
1.4 |
SRCREC *source = NULL; /* our list of sources */ |
33 |
greg |
1.1 |
int nsources = 0; /* the number of sources */ |
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35 |
greg |
1.25 |
static CONTRIB *srccnt; /* source contributions in direct() */ |
36 |
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static CNTPTR *cntord; /* source ordering in direct() */ |
37 |
greg |
1.1 |
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38 |
greg |
1.25 |
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39 |
greg |
1.1 |
marksources() /* find and mark source objects */ |
40 |
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{ |
41 |
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register OBJREC *o, *m; |
42 |
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register int i; |
43 |
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44 |
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for (i = 0; i < nobjects; i++) { |
45 |
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46 |
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o = objptr(i); |
47 |
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48 |
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if (o->omod == OVOID) |
49 |
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continue; |
50 |
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51 |
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m = objptr(o->omod); |
52 |
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53 |
greg |
1.24 |
if (!islight(m->otype)) |
54 |
greg |
1.1 |
continue; |
55 |
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56 |
greg |
1.6 |
if (m->oargs.nfargs != (m->otype == MAT_GLOW ? 4 : |
57 |
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m->otype == MAT_SPOT ? 7 : 3)) |
58 |
greg |
1.1 |
objerror(m, USER, "bad # arguments"); |
59 |
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60 |
greg |
1.6 |
if (m->otype == MAT_GLOW && |
61 |
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o->otype != OBJ_SOURCE && |
62 |
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m->oargs.farg[3] <= FTINY) |
63 |
greg |
1.1 |
continue; /* don't bother */ |
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65 |
greg |
1.4 |
if (source == NULL) |
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source = (SRCREC *)malloc(sizeof(SRCREC)); |
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else |
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source = (SRCREC *)realloc((char *)source, |
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(unsigned)(nsources+1)*sizeof(SRCREC)); |
70 |
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if (source == NULL) |
71 |
greg |
1.25 |
goto memerr; |
72 |
greg |
1.1 |
|
73 |
greg |
1.4 |
newsource(&source[nsources], o); |
74 |
greg |
1.1 |
|
75 |
greg |
1.6 |
if (m->otype == MAT_GLOW) { |
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source[nsources].sflags |= SPROX; |
77 |
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source[nsources].sl.prox = m->oargs.farg[3]; |
78 |
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if (o->otype == OBJ_SOURCE) |
79 |
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source[nsources].sflags |= SSKIP; |
80 |
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} else if (m->otype == MAT_SPOT) { |
81 |
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source[nsources].sflags |= SSPOT; |
82 |
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source[nsources].sl.s = makespot(m); |
83 |
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} |
84 |
greg |
1.1 |
nsources++; |
85 |
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} |
86 |
greg |
1.25 |
if (nsources <= 0) { |
87 |
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error(WARNING, "no light sources found"); |
88 |
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return; |
89 |
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} |
90 |
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srccnt = (CONTRIB *)malloc(nsources*sizeof(CONTRIB)); |
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cntord = (CNTPTR *)malloc(nsources*sizeof(CNTPTR)); |
92 |
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if (srccnt != NULL && cntord != NULL) |
93 |
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return; |
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/* fall through */ |
95 |
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memerr: |
96 |
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error(SYSTEM, "out of memory in marksources"); |
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greg |
1.1 |
} |
98 |
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99 |
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100 |
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newsource(src, so) /* add a source to the array */ |
101 |
greg |
1.4 |
register SRCREC *src; |
102 |
greg |
1.1 |
register OBJREC *so; |
103 |
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{ |
104 |
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double cos(), tan(), sqrt(); |
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double theta; |
106 |
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FACE *f; |
107 |
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CONE *co; |
108 |
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int j; |
109 |
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register int i; |
110 |
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111 |
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src->sflags = 0; |
112 |
greg |
1.6 |
src->nhits = 1; src->ntests = 2; /* start probability = 1/2 */ |
113 |
greg |
1.1 |
src->so = so; |
114 |
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115 |
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switch (so->otype) { |
116 |
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case OBJ_SOURCE: |
117 |
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if (so->oargs.nfargs != 4) |
118 |
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objerror(so, USER, "bad arguments"); |
119 |
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src->sflags |= SDISTANT; |
120 |
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VCOPY(src->sloc, so->oargs.farg); |
121 |
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if (normalize(src->sloc) == 0.0) |
122 |
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objerror(so, USER, "zero direction"); |
123 |
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theta = PI/180.0/2.0 * so->oargs.farg[3]; |
124 |
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if (theta <= FTINY) |
125 |
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objerror(so, USER, "zero size"); |
126 |
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src->ss = theta >= PI/4 ? 1.0 : tan(theta); |
127 |
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src->ss2 = 2.0*PI * (1.0 - cos(theta)); |
128 |
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break; |
129 |
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case OBJ_SPHERE: |
130 |
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VCOPY(src->sloc, so->oargs.farg); |
131 |
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src->ss = so->oargs.farg[3]; |
132 |
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src->ss2 = PI * src->ss * src->ss; |
133 |
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break; |
134 |
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case OBJ_FACE: |
135 |
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/* get the face */ |
136 |
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f = getface(so); |
137 |
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/* find the center */ |
138 |
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for (j = 0; j < 3; j++) { |
139 |
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src->sloc[j] = 0.0; |
140 |
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for (i = 0; i < f->nv; i++) |
141 |
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src->sloc[j] += VERTEX(f,i)[j]; |
142 |
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src->sloc[j] /= f->nv; |
143 |
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} |
144 |
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if (!inface(src->sloc, f)) |
145 |
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objerror(so, USER, "cannot hit center"); |
146 |
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src->ss = sqrt(f->area / PI); |
147 |
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src->ss2 = f->area; |
148 |
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break; |
149 |
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case OBJ_RING: |
150 |
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/* get the ring */ |
151 |
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co = getcone(so, 0); |
152 |
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VCOPY(src->sloc, CO_P0(co)); |
153 |
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if (CO_R0(co) > 0.0) |
154 |
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objerror(so, USER, "cannot hit center"); |
155 |
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src->ss = CO_R1(co); |
156 |
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src->ss2 = PI * src->ss * src->ss; |
157 |
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break; |
158 |
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default: |
159 |
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objerror(so, USER, "illegal material"); |
160 |
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} |
161 |
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} |
162 |
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163 |
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164 |
greg |
1.6 |
SPOT * |
165 |
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makespot(m) /* make a spotlight */ |
166 |
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register OBJREC *m; |
167 |
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{ |
168 |
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extern double cos(); |
169 |
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register SPOT *ns; |
170 |
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171 |
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if ((ns = (SPOT *)malloc(sizeof(SPOT))) == NULL) |
172 |
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error(SYSTEM, "out of memory in makespot"); |
173 |
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ns->siz = 2.0*PI * (1.0 - cos(PI/180.0/2.0 * m->oargs.farg[3])); |
174 |
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VCOPY(ns->aim, m->oargs.farg+4); |
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if ((ns->flen = normalize(ns->aim)) == 0.0) |
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objerror(m, USER, "zero focus vector"); |
177 |
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return(ns); |
178 |
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} |
179 |
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180 |
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181 |
greg |
1.1 |
double |
182 |
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srcray(sr, r, sn) /* send a ray to a source, return domega */ |
183 |
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register RAY *sr; /* returned source ray */ |
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RAY *r; /* ray which hit object */ |
185 |
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register int sn; /* source number */ |
186 |
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{ |
187 |
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register double *norm = NULL; /* plane normal */ |
188 |
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double ddot; /* (distance times) cosine */ |
189 |
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FVECT vd; |
190 |
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double d; |
191 |
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register int i; |
192 |
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193 |
greg |
1.4 |
if (source[sn].sflags & SSKIP) |
194 |
greg |
1.1 |
return(0.0); /* skip this source */ |
195 |
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196 |
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rayorigin(sr, r, SHADOW, 1.0); /* ignore limits */ |
197 |
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198 |
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sr->rsrc = sn; /* remember source */ |
199 |
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/* get source direction */ |
200 |
greg |
1.4 |
if (source[sn].sflags & SDISTANT) |
201 |
greg |
1.1 |
/* constant direction */ |
202 |
greg |
1.4 |
VCOPY(sr->rdir, source[sn].sloc); |
203 |
greg |
1.1 |
else { /* compute direction */ |
204 |
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for (i = 0; i < 3; i++) |
205 |
greg |
1.4 |
sr->rdir[i] = source[sn].sloc[i] - sr->rorg[i]; |
206 |
greg |
1.1 |
|
207 |
greg |
1.4 |
if (source[sn].so->otype == OBJ_FACE) |
208 |
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norm = getface(source[sn].so)->norm; |
209 |
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else if (source[sn].so->otype == OBJ_RING) |
210 |
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norm = getcone(source[sn].so,0)->ad; |
211 |
greg |
1.1 |
|
212 |
greg |
1.2 |
if (norm != NULL && (ddot = -DOT(sr->rdir, norm)) <= FTINY) |
213 |
greg |
1.1 |
return(0.0); /* behind surface! */ |
214 |
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} |
215 |
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if (dstrsrc > FTINY) { |
216 |
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/* distribute source direction */ |
217 |
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for (i = 0; i < 3; i++) |
218 |
greg |
1.4 |
vd[i] = dstrsrc * source[sn].ss * (1.0 - 2.0*frandom()); |
219 |
greg |
1.1 |
|
220 |
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if (norm != NULL) { /* project offset */ |
221 |
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d = DOT(vd, norm); |
222 |
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for (i = 0; i < 3; i++) |
223 |
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vd[i] -= d * norm[i]; |
224 |
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} |
225 |
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for (i = 0; i < 3; i++) /* offset source direction */ |
226 |
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sr->rdir[i] += vd[i]; |
227 |
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228 |
greg |
1.4 |
} else if (source[sn].sflags & SDISTANT) |
229 |
greg |
1.1 |
/* already normalized */ |
230 |
greg |
1.4 |
return(source[sn].ss2); |
231 |
greg |
1.1 |
|
232 |
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if ((d = normalize(sr->rdir)) == 0.0) |
233 |
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/* at source! */ |
234 |
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return(0.0); |
235 |
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236 |
greg |
1.4 |
if (source[sn].sflags & SDISTANT) |
237 |
greg |
1.1 |
/* domega constant */ |
238 |
greg |
1.4 |
return(source[sn].ss2); |
239 |
greg |
1.1 |
|
240 |
greg |
1.6 |
/* check proximity */ |
241 |
greg |
1.27 |
if (source[sn].sflags & SPROX && |
242 |
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d > source[sn].sl.prox) |
243 |
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return(0.0); |
244 |
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/* compute dot product */ |
245 |
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if (norm != NULL) |
246 |
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ddot /= d; |
247 |
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else |
248 |
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ddot = 1.0; |
249 |
greg |
1.6 |
/* check angle */ |
250 |
greg |
1.27 |
if (source[sn].sflags & SSPOT) { |
251 |
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if (source[sn].sl.s->siz < 2.0*PI * |
252 |
greg |
1.6 |
(1.0 + DOT(source[sn].sl.s->aim,sr->rdir))) |
253 |
greg |
1.27 |
return(0.0); |
254 |
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d += source[sn].sl.s->flen; /* adjust length */ |
255 |
greg |
1.1 |
} |
256 |
greg |
1.27 |
/* compute domega */ |
257 |
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return(ddot*source[sn].ss2/(d*d)); |
258 |
greg |
1.1 |
} |
259 |
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260 |
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261 |
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sourcehit(r) /* check to see if ray hit distant source */ |
262 |
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register RAY *r; |
263 |
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{ |
264 |
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int first, last; |
265 |
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register int i; |
266 |
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267 |
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if (r->rsrc >= 0) { /* check only one if aimed */ |
268 |
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first = last = r->rsrc; |
269 |
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} else { /* otherwise check all */ |
270 |
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first = 0; last = nsources-1; |
271 |
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} |
272 |
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for (i = first; i <= last; i++) |
273 |
greg |
1.4 |
if (source[i].sflags & SDISTANT) |
274 |
greg |
1.1 |
/* |
275 |
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* Check to see if ray is within |
276 |
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* solid angle of source. |
277 |
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*/ |
278 |
greg |
1.4 |
if (2.0*PI * (1.0 - DOT(source[i].sloc,r->rdir)) |
279 |
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<= source[i].ss2) { |
280 |
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r->ro = source[i].so; |
281 |
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if (!(source[i].sflags & SSKIP)) |
282 |
greg |
1.1 |
break; |
283 |
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} |
284 |
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285 |
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if (r->ro != NULL) { |
286 |
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for (i = 0; i < 3; i++) |
287 |
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r->ron[i] = -r->rdir[i]; |
288 |
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r->rod = 1.0; |
289 |
greg |
1.26 |
r->rox = NULL; |
290 |
greg |
1.1 |
return(1); |
291 |
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} |
292 |
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return(0); |
293 |
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} |
294 |
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295 |
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296 |
greg |
1.4 |
static int |
297 |
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cntcmp(sc1, sc2) /* contribution compare (descending) */ |
298 |
greg |
1.9 |
register CNTPTR *sc1, *sc2; |
299 |
greg |
1.4 |
{ |
300 |
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if (sc1->brt > sc2->brt) |
301 |
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return(-1); |
302 |
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if (sc1->brt < sc2->brt) |
303 |
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return(1); |
304 |
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return(0); |
305 |
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} |
306 |
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307 |
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308 |
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direct(r, f, p) /* add direct component */ |
309 |
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RAY *r; /* ray that hit surface */ |
310 |
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int (*f)(); /* direct component coefficient function */ |
311 |
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char *p; /* data for f */ |
312 |
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{ |
313 |
greg |
1.12 |
extern double pow(); |
314 |
greg |
1.4 |
register int sn; |
315 |
greg |
1.12 |
int nshadcheck, ncnts; |
316 |
greg |
1.10 |
double prob, ourthresh, hwt, test2, hit2; |
317 |
greg |
1.4 |
RAY sr; |
318 |
greg |
1.25 |
/* NOTE: srccnt and cntord global so no recursion */ |
319 |
greg |
1.22 |
if (nsources <= 0) |
320 |
greg |
1.25 |
return; /* no sources?! */ |
321 |
greg |
1.12 |
/* compute number to check */ |
322 |
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nshadcheck = pow((double)nsources, shadcert) + .5; |
323 |
greg |
1.8 |
/* modify threshold */ |
324 |
|
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ourthresh = shadthresh / r->rweight; |
325 |
greg |
1.4 |
/* potential contributions */ |
326 |
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for (sn = 0; sn < nsources; sn++) { |
327 |
greg |
1.9 |
cntord[sn].sno = sn; |
328 |
|
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cntord[sn].brt = 0.0; |
329 |
greg |
1.4 |
/* get source ray */ |
330 |
|
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if ((srccnt[sn].dom = srcray(&sr, r, sn)) == 0.0) |
331 |
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continue; |
332 |
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VCOPY(srccnt[sn].dir, sr.rdir); |
333 |
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/* compute coefficient */ |
334 |
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(*f)(srccnt[sn].val, p, srccnt[sn].dir, srccnt[sn].dom); |
335 |
greg |
1.9 |
cntord[sn].brt = bright(srccnt[sn].val); |
336 |
greg |
1.15 |
if (cntord[sn].brt <= 0.0) |
337 |
greg |
1.4 |
continue; |
338 |
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/* compute intersection */ |
339 |
|
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if (!( source[sn].sflags & SDISTANT ? |
340 |
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sourcehit(&sr) : |
341 |
|
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(*ofun[source[sn].so->otype].funp) |
342 |
greg |
1.25 |
(source[sn].so, &sr) )) { |
343 |
|
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sprintf(errmsg, |
344 |
|
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"aiming failure for light source \"%s\"", |
345 |
|
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source[sn].so->oname); |
346 |
|
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error(WARNING, errmsg); |
347 |
greg |
1.28 |
cntord[sn].brt = 0.0; |
348 |
greg |
1.4 |
continue; |
349 |
greg |
1.25 |
} |
350 |
greg |
1.4 |
/* compute contribution */ |
351 |
greg |
1.19 |
raycont(&sr); |
352 |
greg |
1.4 |
multcolor(srccnt[sn].val, sr.rcol); |
353 |
greg |
1.9 |
cntord[sn].brt = bright(srccnt[sn].val); |
354 |
greg |
1.4 |
} |
355 |
|
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/* sort contributions */ |
356 |
greg |
1.9 |
qsort(cntord, nsources, sizeof(CNTPTR), cntcmp); |
357 |
greg |
1.13 |
{ /* find last */ |
358 |
|
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register int l, m; |
359 |
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360 |
|
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sn = 0; ncnts = l = nsources; |
361 |
|
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while ((m = (sn + ncnts) >> 1) != l) { |
362 |
|
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if (cntord[m].brt > 0.0) |
363 |
|
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sn = m; |
364 |
|
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else |
365 |
|
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ncnts = m; |
366 |
|
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l = m; |
367 |
|
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} |
368 |
|
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} |
369 |
greg |
1.12 |
/* accumulate tail */ |
370 |
|
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for (sn = ncnts-1; sn > 0; sn--) |
371 |
|
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cntord[sn-1].brt += cntord[sn].brt; |
372 |
|
|
/* start with prob=.5 */ |
373 |
|
|
hit2 = 0.5; test2 = 1.0; |
374 |
greg |
1.10 |
/* test for shadows */ |
375 |
greg |
1.12 |
for (sn = 0; sn < ncnts; sn++) { |
376 |
greg |
1.10 |
/* check threshold */ |
377 |
greg |
1.12 |
if ((sn+nshadcheck>=ncnts ? cntord[sn].brt : |
378 |
greg |
1.27 |
cntord[sn].brt-cntord[sn+nshadcheck].brt) |
379 |
|
|
< ourthresh*bright(r->rcol)) |
380 |
greg |
1.4 |
break; |
381 |
|
|
/* get statistics */ |
382 |
greg |
1.9 |
hwt = (double)source[cntord[sn].sno].nhits / |
383 |
|
|
(double)source[cntord[sn].sno].ntests; |
384 |
greg |
1.4 |
test2 += hwt; |
385 |
greg |
1.9 |
source[cntord[sn].sno].ntests++; |
386 |
greg |
1.4 |
/* test for hit */ |
387 |
|
|
rayorigin(&sr, r, SHADOW, 1.0); |
388 |
greg |
1.9 |
VCOPY(sr.rdir, srccnt[cntord[sn].sno].dir); |
389 |
greg |
1.19 |
sr.rsrc = cntord[sn].sno; |
390 |
greg |
1.4 |
if (localhit(&sr, &thescene) && |
391 |
greg |
1.9 |
sr.ro != source[cntord[sn].sno].so) { |
392 |
greg |
1.4 |
/* check for transmission */ |
393 |
greg |
1.19 |
raycont(&sr); |
394 |
greg |
1.5 |
if (bright(sr.rcol) <= FTINY) |
395 |
greg |
1.4 |
continue; /* missed! */ |
396 |
greg |
1.9 |
(*f)(srccnt[cntord[sn].sno].val, p, |
397 |
|
|
srccnt[cntord[sn].sno].dir, |
398 |
|
|
srccnt[cntord[sn].sno].dom); |
399 |
|
|
multcolor(srccnt[cntord[sn].sno].val, sr.rcol); |
400 |
greg |
1.4 |
} |
401 |
|
|
/* add contribution if hit */ |
402 |
greg |
1.9 |
addcolor(r->rcol, srccnt[cntord[sn].sno].val); |
403 |
greg |
1.4 |
hit2 += hwt; |
404 |
greg |
1.9 |
source[cntord[sn].sno].nhits++; |
405 |
greg |
1.4 |
} |
406 |
greg |
1.7 |
/* weighted hit rate */ |
407 |
|
|
hwt = hit2 / test2; |
408 |
greg |
1.20 |
#ifdef DEBUG |
409 |
greg |
1.12 |
sprintf(errmsg, "%d tested, %d untested, %f hit rate\n", |
410 |
|
|
sn, ncnts-sn, hwt); |
411 |
|
|
eputs(errmsg); |
412 |
greg |
1.4 |
#endif |
413 |
|
|
/* add in untested sources */ |
414 |
greg |
1.12 |
for ( ; sn < ncnts; sn++) { |
415 |
greg |
1.9 |
prob = hwt * (double)source[cntord[sn].sno].nhits / |
416 |
|
|
(double)source[cntord[sn].sno].ntests; |
417 |
|
|
scalecolor(srccnt[cntord[sn].sno].val, prob); |
418 |
|
|
addcolor(r->rcol, srccnt[cntord[sn].sno].val); |
419 |
greg |
1.4 |
} |
420 |
|
|
} |
421 |
|
|
|
422 |
|
|
|
423 |
greg |
1.1 |
#define wrongsource(m, r) (m->otype!=MAT_ILLUM && \ |
424 |
|
|
r->rsrc>=0 && \ |
425 |
greg |
1.4 |
source[r->rsrc].so!=r->ro) |
426 |
greg |
1.1 |
|
427 |
|
|
#define badambient(m, r) ((r->crtype&(AMBIENT|SHADOW))==AMBIENT && \ |
428 |
greg |
1.6 |
!(r->rtype&REFLECTED) && /* hack! */\ |
429 |
|
|
!(m->otype==MAT_GLOW&&r->rot>m->oargs.farg[3])) |
430 |
greg |
1.1 |
|
431 |
|
|
#define passillum(m, r) (m->otype==MAT_ILLUM && \ |
432 |
greg |
1.4 |
!(r->rsrc>=0&&source[r->rsrc].so==r->ro)) |
433 |
greg |
1.1 |
|
434 |
|
|
|
435 |
|
|
m_light(m, r) /* ray hit a light source */ |
436 |
|
|
register OBJREC *m; |
437 |
|
|
register RAY *r; |
438 |
|
|
{ |
439 |
|
|
/* check for over-counting */ |
440 |
|
|
if (wrongsource(m, r) || badambient(m, r)) |
441 |
|
|
return; |
442 |
|
|
/* check for passed illum */ |
443 |
|
|
if (passillum(m, r)) { |
444 |
|
|
|
445 |
|
|
if (m->oargs.nsargs < 1 || !strcmp(m->oargs.sarg[0], VOIDID)) |
446 |
|
|
raytrans(r); |
447 |
|
|
else |
448 |
|
|
rayshade(r, modifier(m->oargs.sarg[0])); |
449 |
|
|
|
450 |
|
|
/* otherwise treat as source */ |
451 |
|
|
} else { |
452 |
greg |
1.16 |
/* check for behind */ |
453 |
|
|
if (r->rod < 0.0) |
454 |
|
|
return; |
455 |
greg |
1.1 |
/* get distribution pattern */ |
456 |
|
|
raytexture(r, m->omod); |
457 |
|
|
/* get source color */ |
458 |
|
|
setcolor(r->rcol, m->oargs.farg[0], |
459 |
|
|
m->oargs.farg[1], |
460 |
|
|
m->oargs.farg[2]); |
461 |
|
|
/* modify value */ |
462 |
|
|
multcolor(r->rcol, r->pcol); |
463 |
greg |
1.21 |
/* assign distance */ |
464 |
|
|
r->rt = r->rot; |
465 |
greg |
1.1 |
} |
466 |
|
|
} |