32 |
|
* 4+ func datafile funcfile v0 .. transform |
33 |
|
* 0 |
34 |
|
* 4+ red grn blu specularity A5 .. |
35 |
+ |
* |
36 |
+ |
* Arguments for MAT_TFUNC are: |
37 |
+ |
* 2+ func funcfile transform |
38 |
+ |
* 0 |
39 |
+ |
* 4+ red grn blu rspec trans tspec A7 .. |
40 |
+ |
* |
41 |
+ |
* Arguments for MAT_TDATA are: |
42 |
+ |
* 4+ func datafile funcfile v0 .. transform |
43 |
+ |
* 0 |
44 |
+ |
* 4+ red grn blu rspec trans tspec A7 .. |
45 |
+ |
* |
46 |
+ |
* Arguments for the more general MAT_BRTDF are: |
47 |
+ |
* 10+ rrefl grefl brefl |
48 |
+ |
* rtrns gtrns btrns |
49 |
+ |
* rbrtd gbrtd bbrtd |
50 |
+ |
* funcfile transform |
51 |
+ |
* 0 |
52 |
+ |
* 6+ red grn blu rspec trans tspec A7 .. |
53 |
+ |
* |
54 |
+ |
* In addition to the normal variables available to functions, |
55 |
+ |
* we define the following: |
56 |
+ |
* NxP, NyP, NzP - perturbed surface normal |
57 |
+ |
* RdotP - perturbed ray dot product |
58 |
+ |
* CrP, CgP, CbP - perturbed material color |
59 |
|
*/ |
60 |
|
|
61 |
|
extern double funvalue(), varvalue(); |
62 |
+ |
extern XF funcxf; |
63 |
|
|
64 |
|
typedef struct { |
65 |
|
OBJREC *mp; /* material pointer */ |
66 |
|
RAY *pr; /* intersected ray */ |
67 |
< |
DATARRAY *dp; /* data array for PDATA or MDATA */ |
67 |
> |
DATARRAY *dp; /* data array for PDATA, MDATA or TDATA */ |
68 |
|
COLOR mcolor; /* color of this material */ |
69 |
< |
COLOR scolor; /* color of specular component */ |
69 |
> |
COLOR scolor; /* color of specular reflection */ |
70 |
|
double rspec; /* specular reflection */ |
71 |
|
double rdiff; /* diffuse reflection */ |
72 |
+ |
double trans; /* transmissivity */ |
73 |
+ |
double tspec; /* specular transmission */ |
74 |
+ |
double tdiff; /* diffuse transmission */ |
75 |
|
FVECT pnorm; /* perturbed surface normal */ |
76 |
|
double pdot; /* perturbed dot product */ |
77 |
|
} BRDFDAT; /* BRDF material data */ |
83 |
|
FVECT ldir; /* light source direction */ |
84 |
|
double omega; /* light source size */ |
85 |
|
{ |
58 |
– |
extern XF funcxf; |
86 |
|
double ldot; |
87 |
|
double dtmp; |
88 |
|
COLOR ctmp; |
89 |
|
FVECT ldx; |
90 |
|
double pt[MAXDIM]; |
91 |
+ |
register char **sa; |
92 |
|
register int i; |
93 |
|
|
94 |
|
setcolor(cval, 0.0, 0.0, 0.0); |
95 |
|
|
96 |
|
ldot = DOT(np->pnorm, ldir); |
97 |
|
|
98 |
< |
if (ldot < 0.0) |
98 |
> |
if (ldot <= FTINY && ldot >= -FTINY) |
99 |
> |
return; /* too close to grazing */ |
100 |
> |
if (ldot < 0.0 ? np->trans <= FTINY : np->trans >= 1.0-FTINY) |
101 |
|
return; /* wrong side */ |
102 |
|
|
103 |
< |
if (np->rdiff > FTINY) { |
103 |
> |
if (ldot > 0.0 && np->rdiff > FTINY) { |
104 |
|
/* |
105 |
|
* Compute and add diffuse reflected component to returned |
106 |
|
* color. The diffuse reflected component will always be |
111 |
|
scalecolor(ctmp, dtmp); |
112 |
|
addcolor(cval, ctmp); |
113 |
|
} |
114 |
< |
if (np->rspec > FTINY) { |
114 |
> |
if (ldot < 0.0 && np->tdiff > FTINY) { |
115 |
|
/* |
116 |
< |
* Compute specular component. |
116 |
> |
* Diffuse transmitted component. |
117 |
|
*/ |
118 |
< |
setfunc(np->mp, np->pr); |
119 |
< |
/* transform light vector */ |
120 |
< |
multv3(ldx, ldir, funcxf.xfm); |
121 |
< |
for (i = 0; i < 3; i++) |
92 |
< |
ldx[i] /= funcxf.sca; |
93 |
< |
/* evaluate BRDF */ |
94 |
< |
errno = 0; |
95 |
< |
if (np->dp == NULL) |
96 |
< |
dtmp = funvalue(np->mp->oargs.sarg[0], 3, ldx); |
97 |
< |
else { |
98 |
< |
for (i = 0; i < np->dp->nd; i++) |
99 |
< |
pt[i] = funvalue(np->mp->oargs.sarg[3+i], |
100 |
< |
3, ldx); |
101 |
< |
dtmp = datavalue(np->dp, pt); |
102 |
< |
dtmp = funvalue(np->mp->oargs.sarg[0], 1, &dtmp); |
103 |
< |
} |
104 |
< |
if (errno) |
105 |
< |
goto computerr; |
106 |
< |
if (dtmp > FTINY) { |
107 |
< |
copycolor(ctmp, np->scolor); |
108 |
< |
dtmp *= ldot * omega; |
109 |
< |
scalecolor(ctmp, dtmp); |
110 |
< |
addcolor(cval, ctmp); |
111 |
< |
} |
118 |
> |
copycolor(ctmp, np->mcolor); |
119 |
> |
dtmp = -ldot * omega * np->tdiff / PI; |
120 |
> |
scalecolor(ctmp, dtmp); |
121 |
> |
addcolor(cval, ctmp); |
122 |
|
} |
123 |
+ |
if (ldot > 0.0 ? np->rspec <= FTINY : np->tspec <= FTINY) |
124 |
+ |
return; /* no specular component */ |
125 |
+ |
/* set up function */ |
126 |
+ |
setfunc(np->mp, np->pr); |
127 |
+ |
sa = np->mp->oargs.sarg; |
128 |
+ |
errno = 0; |
129 |
+ |
/* transform light vector */ |
130 |
+ |
multv3(ldx, ldir, funcxf.xfm); |
131 |
+ |
for (i = 0; i < 3; i++) |
132 |
+ |
ldx[i] /= funcxf.sca; |
133 |
+ |
/* compute BRTDF */ |
134 |
+ |
if (np->mp->otype == MAT_BRTDF) { |
135 |
+ |
colval(ctmp,RED) = funvalue(sa[6], 3, ldx); |
136 |
+ |
if (sa[7] == sa[6]) |
137 |
+ |
colval(ctmp,GRN) = colval(ctmp,RED); |
138 |
+ |
else |
139 |
+ |
colval(ctmp,GRN) = funvalue(sa[7], 3, ldx); |
140 |
+ |
if (sa[8] == sa[6]) |
141 |
+ |
colval(ctmp,BLU) = colval(ctmp,RED); |
142 |
+ |
else if (sa[8] == sa[7]) |
143 |
+ |
colval(ctmp,BLU) = colval(ctmp,GRN); |
144 |
+ |
else |
145 |
+ |
colval(ctmp,BLU) = funvalue(sa[8], 3, ldx); |
146 |
+ |
dtmp = bright(ctmp); |
147 |
+ |
} else if (np->dp == NULL) { |
148 |
+ |
dtmp = funvalue(sa[0], 3, ldx); |
149 |
+ |
setcolor(ctmp, dtmp, dtmp, dtmp); |
150 |
+ |
} else { |
151 |
+ |
for (i = 0; i < np->dp->nd; i++) |
152 |
+ |
pt[i] = funvalue(sa[3+i], 3, ldx); |
153 |
+ |
dtmp = datavalue(np->dp, pt); |
154 |
+ |
dtmp = funvalue(sa[0], 1, &dtmp); |
155 |
+ |
setcolor(ctmp, dtmp, dtmp, dtmp); |
156 |
+ |
} |
157 |
+ |
if (errno) |
158 |
+ |
goto computerr; |
159 |
+ |
if (dtmp <= FTINY) |
160 |
+ |
return; |
161 |
+ |
if (ldot > 0.0) { |
162 |
+ |
/* |
163 |
+ |
* Compute reflected non-diffuse component. |
164 |
+ |
*/ |
165 |
+ |
multcolor(ctmp, np->scolor); |
166 |
+ |
dtmp = ldot * omega; |
167 |
+ |
scalecolor(ctmp, dtmp); |
168 |
+ |
addcolor(cval, ctmp); |
169 |
+ |
} else { |
170 |
+ |
/* |
171 |
+ |
* Compute transmitted non-diffuse component. |
172 |
+ |
*/ |
173 |
+ |
dtmp = -ldot * omega * np->tspec; |
174 |
+ |
scalecolor(ctmp, dtmp); |
175 |
+ |
addcolor(cval, ctmp); |
176 |
+ |
} |
177 |
|
return; |
178 |
|
computerr: |
179 |
|
objerror(np->mp, WARNING, "compute error"); |
185 |
|
register OBJREC *m; |
186 |
|
register RAY *r; |
187 |
|
{ |
188 |
+ |
int minsa, minfa; |
189 |
|
BRDFDAT nd; |
190 |
|
COLOR ctmp; |
191 |
+ |
double dtmp; |
192 |
+ |
FVECT vec; |
193 |
|
register int i; |
194 |
< |
|
195 |
< |
if (m->oargs.nsargs < 2 || m->oargs.nfargs < 4) |
194 |
> |
/* check arguments */ |
195 |
> |
switch (m->otype) { |
196 |
> |
case MAT_PFUNC: case MAT_MFUNC: |
197 |
> |
minsa = 2; minfa = 4; break; |
198 |
> |
case MAT_PDATA: case MAT_MDATA: |
199 |
> |
minsa = 4; minfa = 4; break; |
200 |
> |
case MAT_TFUNC: |
201 |
> |
minsa = 2; minfa = 6; break; |
202 |
> |
case MAT_TDATA: |
203 |
> |
minsa = 4; minfa = 6; break; |
204 |
> |
case MAT_BRTDF: |
205 |
> |
minsa = 10; minfa = 6; break; |
206 |
> |
} |
207 |
> |
if (m->oargs.nsargs < minsa || m->oargs.nfargs < minfa) |
208 |
|
objerror(m, USER, "bad # arguments"); |
130 |
– |
/* easy shadow test */ |
131 |
– |
if (r->crtype & SHADOW) |
132 |
– |
return; |
209 |
|
nd.mp = m; |
210 |
|
nd.pr = r; |
211 |
+ |
/* get specular component */ |
212 |
+ |
nd.rspec = m->oargs.farg[3]; |
213 |
+ |
/* compute transmission */ |
214 |
+ |
if (m->otype == MAT_TFUNC || m->otype == MAT_TDATA |
215 |
+ |
|| m->otype == MAT_BRTDF) { |
216 |
+ |
nd.trans = m->oargs.farg[4]*(1.0 - nd.rspec); |
217 |
+ |
nd.tspec = nd.trans * m->oargs.farg[5]; |
218 |
+ |
nd.tdiff = nd.trans - nd.tspec; |
219 |
+ |
} else |
220 |
+ |
nd.tdiff = nd.tspec = nd.trans = 0.0; |
221 |
+ |
/* early shadow check */ |
222 |
+ |
if (r->crtype & SHADOW && (m->otype != MAT_BRTDF || nd.tspec <= FTINY)) |
223 |
+ |
return; |
224 |
+ |
/* diffuse reflection */ |
225 |
+ |
nd.rdiff = 1.0 - nd.trans - nd.rspec; |
226 |
+ |
/* get material color */ |
227 |
+ |
setcolor(nd.mcolor, m->oargs.farg[0], |
228 |
+ |
m->oargs.farg[1], |
229 |
+ |
m->oargs.farg[2]); |
230 |
+ |
/* fix orientation */ |
231 |
+ |
if (r->rod < 0.0) |
232 |
+ |
flipsurface(r); |
233 |
+ |
/* get modifiers */ |
234 |
+ |
raytexture(r, m->omod); |
235 |
+ |
nd.pdot = raynormal(nd.pnorm, r); /* perturb normal */ |
236 |
+ |
multcolor(nd.mcolor, r->pcol); /* modify material color */ |
237 |
+ |
r->rt = r->rot; /* default ray length */ |
238 |
|
/* load auxiliary files */ |
239 |
< |
if (m->otype == MAT_PDATA || m->otype == MAT_MDATA) { |
239 |
> |
if (m->otype == MAT_PDATA || m->otype == MAT_MDATA |
240 |
> |
|| m->otype == MAT_TDATA) { |
241 |
|
nd.dp = getdata(m->oargs.sarg[1]); |
242 |
|
for (i = 3; i < m->oargs.nsargs; i++) |
243 |
|
if (m->oargs.sarg[i][0] == '-') |
246 |
|
objerror(m, USER, "dimension error"); |
247 |
|
if (!fundefined(m->oargs.sarg[3])) |
248 |
|
loadfunc(m->oargs.sarg[2]); |
249 |
+ |
} else if (m->otype == MAT_BRTDF) { |
250 |
+ |
nd.dp = NULL; |
251 |
+ |
if (!fundefined(m->oargs.sarg[7])) |
252 |
+ |
loadfunc(m->oargs.sarg[9]); |
253 |
|
} else { |
254 |
|
nd.dp = NULL; |
255 |
|
if (!fundefined(m->oargs.sarg[0])) |
256 |
|
loadfunc(m->oargs.sarg[1]); |
257 |
|
} |
258 |
< |
/* get material color */ |
259 |
< |
setcolor(nd.mcolor, m->oargs.farg[0], |
260 |
< |
m->oargs.farg[1], |
261 |
< |
m->oargs.farg[2]); |
262 |
< |
/* get roughness */ |
263 |
< |
if (r->rod < 0.0) |
264 |
< |
flipsurface(r); |
265 |
< |
/* get modifiers */ |
266 |
< |
raytexture(r, m->omod); |
267 |
< |
nd.pdot = raynormal(nd.pnorm, r); /* perturb normal */ |
268 |
< |
multcolor(nd.mcolor, r->pcol); /* modify material color */ |
269 |
< |
r->rt = r->rot; /* default ray length */ |
270 |
< |
/* get specular component */ |
271 |
< |
nd.rspec = m->oargs.farg[3]; |
272 |
< |
|
258 |
> |
/* set special variables */ |
259 |
> |
setfunc(m, r); |
260 |
> |
multv3(vec, nd.pnorm, funcxf.xfm); |
261 |
> |
varset("NxP", '=', vec[0]/funcxf.sca); |
262 |
> |
varset("NyP", '=', vec[1]/funcxf.sca); |
263 |
> |
varset("NzP", '=', vec[2]/funcxf.sca); |
264 |
> |
varset("RdotP", '=', nd.pdot); |
265 |
> |
varset("CrP", '=', colval(nd.mcolor,RED)); |
266 |
> |
varset("CgP", '=', colval(nd.mcolor,GRN)); |
267 |
> |
varset("CbP", '=', colval(nd.mcolor,BLU)); |
268 |
> |
/* compute transmitted ray */ |
269 |
> |
if (m->otype == MAT_BRTDF && nd.tspec > FTINY) { |
270 |
> |
RAY sr; |
271 |
> |
errno = 0; |
272 |
> |
setcolor(ctmp, varvalue(m->oargs.sarg[0]), |
273 |
> |
varvalue(m->oargs.sarg[1]), |
274 |
> |
varvalue(m->oargs.sarg[2])); |
275 |
> |
scalecolor(ctmp, nd.tspec); |
276 |
> |
if (errno) |
277 |
> |
objerror(m, WARNING, "compute error"); |
278 |
> |
else if ((dtmp = bright(ctmp)) > FTINY && |
279 |
> |
rayorigin(&sr, r, TRANS, dtmp) == 0) { |
280 |
> |
VCOPY(sr.rdir, r->rdir); |
281 |
> |
rayvalue(&sr); |
282 |
> |
multcolor(sr.rcol, ctmp); |
283 |
> |
addcolor(r->rcol, sr.rcol); |
284 |
> |
if (dtmp > .5) |
285 |
> |
r->rt = r->rot + sr.rt; |
286 |
> |
} |
287 |
> |
} |
288 |
> |
if (r->crtype & SHADOW) /* the rest is shadow */ |
289 |
> |
return; |
290 |
|
if (nd.rspec > FTINY) { /* has specular component */ |
291 |
|
/* compute specular color */ |
292 |
|
if (m->otype == MAT_MFUNC || m->otype == MAT_MDATA) |
294 |
|
else |
295 |
|
setcolor(nd.scolor, 1.0, 1.0, 1.0); |
296 |
|
scalecolor(nd.scolor, nd.rspec); |
297 |
+ |
/* compute reflected ray */ |
298 |
+ |
if (m->otype == MAT_BRTDF) { |
299 |
+ |
RAY sr; |
300 |
+ |
errno = 0; |
301 |
+ |
setcolor(ctmp, varvalue(m->oargs.sarg[3]), |
302 |
+ |
varvalue(m->oargs.sarg[4]), |
303 |
+ |
varvalue(m->oargs.sarg[5])); |
304 |
+ |
scalecolor(ctmp, nd.rspec); |
305 |
+ |
if (errno) |
306 |
+ |
objerror(m, WARNING, "compute error"); |
307 |
+ |
else if ((dtmp = bright(ctmp)) > FTINY && |
308 |
+ |
rayorigin(&sr, r, REFLECTED, dtmp) == 0) { |
309 |
+ |
for (i = 0; i < 3; i++) |
310 |
+ |
sr.rdir[i] = r->rdir[i] + |
311 |
+ |
2.0*nd.pdot*nd.pnorm[i]; |
312 |
+ |
rayvalue(&sr); |
313 |
+ |
multcolor(sr.rcol, ctmp); |
314 |
+ |
addcolor(r->rcol, sr.rcol); |
315 |
+ |
} |
316 |
+ |
} |
317 |
|
} |
173 |
– |
/* diffuse reflection */ |
174 |
– |
nd.rdiff = 1.0 - nd.rspec; |
318 |
|
/* compute ambient */ |
319 |
|
if (nd.rdiff > FTINY) { |
320 |
|
ambient(ctmp, r); |
321 |
+ |
if (m->otype == MAT_BRTDF) |
322 |
+ |
scalecolor(ctmp, nd.rdiff); |
323 |
+ |
else |
324 |
+ |
scalecolor(ctmp, 1.0-nd.trans); |
325 |
|
multcolor(ctmp, nd.mcolor); /* modified by material color */ |
326 |
|
addcolor(r->rcol, ctmp); /* add to returned color */ |
327 |
+ |
} |
328 |
+ |
if (nd.tdiff > FTINY) { /* from other side */ |
329 |
+ |
flipsurface(r); |
330 |
+ |
ambient(ctmp, r); |
331 |
+ |
if (m->otype == MAT_BRTDF) |
332 |
+ |
scalecolor(ctmp, nd.tdiff); |
333 |
+ |
else |
334 |
+ |
scalecolor(ctmp, nd.trans); |
335 |
+ |
multcolor(ctmp, nd.mcolor); |
336 |
+ |
addcolor(r->rcol, ctmp); |
337 |
+ |
flipsurface(r); |
338 |
|
} |
339 |
|
/* add direct component */ |
340 |
|
direct(r, dirbrdf, &nd); |