1 |
/* Copyright (c) 1991 Regents of the University of California */ |
2 |
|
3 |
#ifndef lint |
4 |
static char SCCSid[] = "$SunId$ LBL"; |
5 |
#endif |
6 |
|
7 |
/* |
8 |
* ambient.c - routines dealing with ambient (inter-reflected) component. |
9 |
* |
10 |
* The macro AMBFLUSH (if defined) is the number of ambient values |
11 |
* to wait before flushing to the ambient file. |
12 |
* |
13 |
* 5/9/86 |
14 |
*/ |
15 |
|
16 |
#include "ray.h" |
17 |
|
18 |
#include "octree.h" |
19 |
|
20 |
#include "otypes.h" |
21 |
|
22 |
#include "ambient.h" |
23 |
|
24 |
#include "random.h" |
25 |
|
26 |
#define OCTSCALE 0.5 /* ceil((valid rad.)/(cube size)) */ |
27 |
|
28 |
typedef struct ambtree { |
29 |
AMBVAL *alist; /* ambient value list */ |
30 |
struct ambtree *kid; /* 8 child nodes */ |
31 |
} AMBTREE; /* ambient octree */ |
32 |
|
33 |
extern CUBE thescene; /* contains space boundaries */ |
34 |
|
35 |
#define MAXASET 511 /* maximum number of elements in ambient set */ |
36 |
OBJECT ambset[MAXASET+1]={0}; /* ambient include/exclude set */ |
37 |
|
38 |
double maxarad; /* maximum ambient radius */ |
39 |
double minarad; /* minimum ambient radius */ |
40 |
|
41 |
static AMBTREE atrunk; /* our ambient trunk node */ |
42 |
|
43 |
static FILE *ambfp = NULL; /* ambient file pointer */ |
44 |
|
45 |
#define newambval() (AMBVAL *)bmalloc(sizeof(AMBVAL)) |
46 |
|
47 |
#define newambtree() (AMBTREE *)calloc(8, sizeof(AMBTREE)) |
48 |
|
49 |
|
50 |
setambres(ar) /* set ambient resolution */ |
51 |
int ar; |
52 |
{ |
53 |
/* set min & max radii */ |
54 |
if (ar <= 0) { |
55 |
minarad = 0.0; |
56 |
maxarad = thescene.cusize / 2.0; |
57 |
} else { |
58 |
minarad = thescene.cusize / ar; |
59 |
maxarad = 16.0 * minarad; /* heuristic */ |
60 |
if (maxarad > thescene.cusize / 2.0) |
61 |
maxarad = thescene.cusize / 2.0; |
62 |
} |
63 |
} |
64 |
|
65 |
|
66 |
setambient(afile) /* initialize calculation */ |
67 |
char *afile; |
68 |
{ |
69 |
long ftell(); |
70 |
AMBVAL amb; |
71 |
/* init ambient limits */ |
72 |
setambres(ambres); |
73 |
/* open ambient file */ |
74 |
if (afile != NULL) |
75 |
if ((ambfp = fopen(afile, "r+")) != NULL) { |
76 |
while (fread((char *)&amb,sizeof(AMBVAL),1,ambfp) == 1) |
77 |
avinsert(&amb, &atrunk, thescene.cuorg, |
78 |
thescene.cusize); |
79 |
/* align */ |
80 |
fseek(ambfp, -(ftell(ambfp)%sizeof(AMBVAL)), 1); |
81 |
} else if ((ambfp = fopen(afile, "w")) == NULL) { |
82 |
sprintf(errmsg, "cannot open ambient file \"%s\"", |
83 |
afile); |
84 |
error(SYSTEM, errmsg); |
85 |
} |
86 |
} |
87 |
|
88 |
|
89 |
ambnotify(obj) /* record new modifier */ |
90 |
OBJECT obj; |
91 |
{ |
92 |
static int hitlimit = 0; |
93 |
register OBJREC *o = objptr(obj); |
94 |
register char **amblp; |
95 |
|
96 |
if (hitlimit || !ismodifier(o->otype)) |
97 |
return; |
98 |
for (amblp = amblist; *amblp != NULL; amblp++) |
99 |
if (!strcmp(o->oname, *amblp)) { |
100 |
if (ambset[0] >= MAXASET) { |
101 |
error(WARNING, "too many modifiers in ambient list"); |
102 |
hitlimit++; |
103 |
return; /* should this be fatal? */ |
104 |
} |
105 |
insertelem(ambset, obj); |
106 |
return; |
107 |
} |
108 |
} |
109 |
|
110 |
|
111 |
ambient(acol, r) /* compute ambient component for ray */ |
112 |
COLOR acol; |
113 |
register RAY *r; |
114 |
{ |
115 |
static int rdepth = 0; /* ambient recursion */ |
116 |
double d; |
117 |
|
118 |
if (ambdiv <= 0) /* no ambient calculation */ |
119 |
goto dumbamb; |
120 |
/* check number of bounces */ |
121 |
if (rdepth >= ambounce) |
122 |
goto dumbamb; |
123 |
/* check ambient list */ |
124 |
if (ambincl != -1 && r->ro != NULL && |
125 |
ambincl != inset(ambset, r->ro->omod)) |
126 |
goto dumbamb; |
127 |
|
128 |
if (ambacc <= FTINY) { /* no ambient storage */ |
129 |
rdepth++; |
130 |
d = doambient(acol, r, r->rweight, NULL, NULL); |
131 |
rdepth--; |
132 |
if (d == 0.0) |
133 |
goto dumbamb; |
134 |
return; |
135 |
} |
136 |
/* get ambient value */ |
137 |
setcolor(acol, 0.0, 0.0, 0.0); |
138 |
d = sumambient(acol, r, rdepth, |
139 |
&atrunk, thescene.cuorg, thescene.cusize); |
140 |
if (d > FTINY) |
141 |
scalecolor(acol, 1.0/d); |
142 |
else { |
143 |
d = makeambient(acol, r, rdepth++); |
144 |
rdepth--; |
145 |
} |
146 |
if (d > FTINY) |
147 |
return; |
148 |
dumbamb: /* return global value */ |
149 |
copycolor(acol, ambval); |
150 |
} |
151 |
|
152 |
|
153 |
double |
154 |
sumambient(acol, r, al, at, c0, s) /* get interpolated ambient value */ |
155 |
COLOR acol; |
156 |
register RAY *r; |
157 |
int al; |
158 |
AMBTREE *at; |
159 |
FVECT c0; |
160 |
double s; |
161 |
{ |
162 |
extern double sqrt(); |
163 |
double d, e1, e2, wt, wsum; |
164 |
COLOR ct; |
165 |
FVECT ck0; |
166 |
int i; |
167 |
register int j; |
168 |
register AMBVAL *av; |
169 |
/* do this node */ |
170 |
wsum = 0.0; |
171 |
for (av = at->alist; av != NULL; av = av->next) { |
172 |
/* |
173 |
* Ambient level test. |
174 |
*/ |
175 |
if (av->lvl > al || av->weight < r->rweight-FTINY) |
176 |
continue; |
177 |
/* |
178 |
* Ambient radius test. |
179 |
*/ |
180 |
e1 = 0.0; |
181 |
for (j = 0; j < 3; j++) { |
182 |
d = av->pos[j] - r->rop[j]; |
183 |
e1 += d * d; |
184 |
} |
185 |
e1 /= av->rad * av->rad; |
186 |
if (e1 > ambacc*ambacc*1.21) |
187 |
continue; |
188 |
/* |
189 |
* Normal direction test. |
190 |
*/ |
191 |
e2 = (1.0 - DOT(av->dir, r->ron)) * r->rweight; |
192 |
if (e2 < 0.0) e2 = 0.0; |
193 |
if (e1 + e2 > ambacc*ambacc*1.21) |
194 |
continue; |
195 |
/* |
196 |
* Ray behind test. |
197 |
*/ |
198 |
d = 0.0; |
199 |
for (j = 0; j < 3; j++) |
200 |
d += (r->rop[j] - av->pos[j]) * |
201 |
(av->dir[j] + r->ron[j]); |
202 |
if (d*0.5 < -minarad*ambacc-.001) |
203 |
continue; |
204 |
/* |
205 |
* Jittering final test reduces image artifacts. |
206 |
*/ |
207 |
wt = sqrt(e1) + sqrt(e2); |
208 |
wt *= .9 + .2*urand(9015+samplendx); |
209 |
if (wt > ambacc) |
210 |
continue; |
211 |
if (wt <= 1e-3) |
212 |
wt = 1e3; |
213 |
else |
214 |
wt = 1.0 / wt; |
215 |
wsum += wt; |
216 |
extambient(ct, av, r->rop, r->ron); |
217 |
scalecolor(ct, wt); |
218 |
addcolor(acol, ct); |
219 |
} |
220 |
if (at->kid == NULL) |
221 |
return(wsum); |
222 |
/* do children */ |
223 |
s *= 0.5; |
224 |
for (i = 0; i < 8; i++) { |
225 |
for (j = 0; j < 3; j++) { |
226 |
ck0[j] = c0[j]; |
227 |
if (1<<j & i) |
228 |
ck0[j] += s; |
229 |
if (r->rop[j] < ck0[j] - OCTSCALE*s) |
230 |
break; |
231 |
if (r->rop[j] > ck0[j] + (1.0+OCTSCALE)*s) |
232 |
break; |
233 |
} |
234 |
if (j == 3) |
235 |
wsum += sumambient(acol, r, al, at->kid+i, ck0, s); |
236 |
} |
237 |
return(wsum); |
238 |
} |
239 |
|
240 |
|
241 |
double |
242 |
makeambient(acol, r, al) /* make a new ambient value */ |
243 |
COLOR acol; |
244 |
register RAY *r; |
245 |
int al; |
246 |
{ |
247 |
AMBVAL amb; |
248 |
FVECT gp, gd; |
249 |
/* compute weight */ |
250 |
amb.weight = pow(AVGREFL, (double)al); |
251 |
if (r->rweight < 0.2*amb.weight) /* heuristic */ |
252 |
amb.weight = r->rweight; |
253 |
/* compute ambient */ |
254 |
amb.rad = doambient(acol, r, amb.weight, gp, gd); |
255 |
if (amb.rad == 0.0) |
256 |
return(0.0); |
257 |
/* store it */ |
258 |
VCOPY(amb.pos, r->rop); |
259 |
VCOPY(amb.dir, r->ron); |
260 |
amb.lvl = al; |
261 |
copycolor(amb.val, acol); |
262 |
VCOPY(amb.gpos, gp); |
263 |
VCOPY(amb.gdir, gd); |
264 |
/* insert into tree */ |
265 |
avinsert(&amb, &atrunk, thescene.cuorg, thescene.cusize); |
266 |
avsave(&amb); /* write to file */ |
267 |
return(amb.rad); |
268 |
} |
269 |
|
270 |
|
271 |
extambient(cr, ap, pv, nv) /* extrapolate value at pv, nv */ |
272 |
COLOR cr; |
273 |
register AMBVAL *ap; |
274 |
FVECT pv, nv; |
275 |
{ |
276 |
FVECT v1, v2; |
277 |
register int i; |
278 |
double d; |
279 |
|
280 |
d = 1.0; /* zeroeth order */ |
281 |
/* gradient due to translation */ |
282 |
for (i = 0; i < 3; i++) |
283 |
d += ap->gpos[i]*(pv[i]-ap->pos[i]); |
284 |
/* gradient due to rotation */ |
285 |
VCOPY(v1, ap->dir); |
286 |
fcross(v2, v1, nv); |
287 |
d += DOT(ap->gdir, v2); |
288 |
if (d <= 0.0) { |
289 |
setcolor(cr, 0.0, 0.0, 0.0); |
290 |
return; |
291 |
} |
292 |
copycolor(cr, ap->val); |
293 |
scalecolor(cr, d); |
294 |
} |
295 |
|
296 |
|
297 |
static |
298 |
avsave(av) /* save an ambient value */ |
299 |
AMBVAL *av; |
300 |
{ |
301 |
#ifdef AMBFLUSH |
302 |
static int nunflshed = 0; |
303 |
#endif |
304 |
if (ambfp == NULL) |
305 |
return; |
306 |
if (fwrite((char *)av, sizeof(AMBVAL), 1, ambfp) != 1) |
307 |
goto writerr; |
308 |
#ifdef AMBFLUSH |
309 |
if (++nunflshed >= AMBFLUSH) { |
310 |
if (fflush(ambfp) == EOF) |
311 |
goto writerr; |
312 |
nunflshed = 0; |
313 |
} |
314 |
#endif |
315 |
return; |
316 |
writerr: |
317 |
error(SYSTEM, "error writing ambient file"); |
318 |
} |
319 |
|
320 |
|
321 |
static |
322 |
avinsert(aval, at, c0, s) /* insert ambient value in a tree */ |
323 |
AMBVAL *aval; |
324 |
register AMBTREE *at; |
325 |
FVECT c0; |
326 |
double s; |
327 |
{ |
328 |
FVECT ck0; |
329 |
int branch; |
330 |
register AMBVAL *av; |
331 |
register int i; |
332 |
|
333 |
if ((av = newambval()) == NULL) |
334 |
goto memerr; |
335 |
copystruct(av, aval); |
336 |
VCOPY(ck0, c0); |
337 |
while (s*(OCTSCALE/2) > av->rad*ambacc) { |
338 |
if (at->kid == NULL) |
339 |
if ((at->kid = newambtree()) == NULL) |
340 |
goto memerr; |
341 |
s *= 0.5; |
342 |
branch = 0; |
343 |
for (i = 0; i < 3; i++) |
344 |
if (av->pos[i] > ck0[i] + s) { |
345 |
ck0[i] += s; |
346 |
branch |= 1 << i; |
347 |
} |
348 |
at = at->kid + branch; |
349 |
} |
350 |
av->next = at->alist; |
351 |
at->alist = av; |
352 |
return; |
353 |
memerr: |
354 |
error(SYSTEM, "out of memory in avinsert"); |
355 |
} |