| 1 | greg | 1.1 | #ifndef lint | 
| 2 | schorsch | 2.19 | static const char       RCSid[] = "$Id: m_brdf.c,v 2.18 2003/03/05 16:16:53 greg Exp $"; | 
| 3 | greg | 1.1 | #endif | 
| 4 |  |  | /* | 
| 5 |  |  | *  Shading for materials with arbitrary BRDF's | 
| 6 |  |  | */ | 
| 7 |  |  |  | 
| 8 | greg | 2.16 | #include "copyright.h" | 
| 9 | greg | 2.15 |  | 
| 10 | greg | 1.1 | #include  "ray.h" | 
| 11 |  |  |  | 
| 12 |  |  | #include  "data.h" | 
| 13 |  |  |  | 
| 14 |  |  | #include  "otypes.h" | 
| 15 |  |  |  | 
| 16 | greg | 2.2 | #include  "func.h" | 
| 17 |  |  |  | 
| 18 | greg | 1.1 | /* | 
| 19 |  |  | *      Arguments to this material include the color and specularity. | 
| 20 |  |  | *  String arguments include the reflection function and files. | 
| 21 |  |  | *  The BRDF is currently used just for the specular component to light | 
| 22 |  |  | *  sources.  Reflectance values or data coordinates are functions | 
| 23 | greg | 2.7 | *  of the direction to the light source.  (Data modification functions | 
| 24 |  |  | *  are passed the source direction as args 2-4.) | 
| 25 | greg | 1.1 | *      We orient the surface towards the incoming ray, so a single | 
| 26 |  |  | *  surface can be used to represent an infinitely thin object. | 
| 27 |  |  | * | 
| 28 |  |  | *  Arguments for MAT_PFUNC and MAT_MFUNC are: | 
| 29 | greg | 1.4 | *      2+      func    funcfile        transform | 
| 30 | greg | 1.1 | *      0 | 
| 31 | greg | 1.4 | *      4+      red     grn     blu     specularity     A5 .. | 
| 32 | greg | 1.1 | * | 
| 33 |  |  | *  Arguments for MAT_PDATA and MAT_MDATA are: | 
| 34 | greg | 1.4 | *      4+      func    datafile        funcfile        v0 ..   transform | 
| 35 | greg | 1.1 | *      0 | 
| 36 | greg | 1.4 | *      4+      red     grn     blu     specularity     A5 .. | 
| 37 | greg | 1.5 | * | 
| 38 |  |  | *  Arguments for MAT_TFUNC are: | 
| 39 |  |  | *      2+      func    funcfile        transform | 
| 40 |  |  | *      0 | 
| 41 |  |  | *      4+      red     grn     blu     rspec   trans   tspec   A7 .. | 
| 42 |  |  | * | 
| 43 |  |  | *  Arguments for MAT_TDATA are: | 
| 44 |  |  | *      4+      func    datafile        funcfile        v0 ..   transform | 
| 45 |  |  | *      0 | 
| 46 |  |  | *      4+      red     grn     blu     rspec   trans   tspec   A7 .. | 
| 47 |  |  | * | 
| 48 |  |  | *  Arguments for the more general MAT_BRTDF are: | 
| 49 |  |  | *      10+     rrefl   grefl   brefl | 
| 50 |  |  | *              rtrns   gtrns   btrns | 
| 51 |  |  | *              rbrtd   gbrtd   bbrtd | 
| 52 |  |  | *              funcfile        transform | 
| 53 |  |  | *      0 | 
| 54 | greg | 2.6 | *      9+      rdf     gdf     bdf | 
| 55 |  |  | *              rdb     gdb     bdb | 
| 56 |  |  | *              rdt     gdt     bdt     A10 .. | 
| 57 | greg | 1.5 | * | 
| 58 |  |  | *      In addition to the normal variables available to functions, | 
| 59 |  |  | *  we define the following: | 
| 60 |  |  | *              NxP, NyP, NzP -         perturbed surface normal | 
| 61 |  |  | *              RdotP -                 perturbed ray dot product | 
| 62 | greg | 2.6 | *              CrP, CgP, CbP -         perturbed material color (or pattern) | 
| 63 | greg | 1.1 | */ | 
| 64 |  |  |  | 
| 65 |  |  | typedef struct { | 
| 66 |  |  | OBJREC  *mp;            /* material pointer */ | 
| 67 |  |  | RAY  *pr;               /* intersected ray */ | 
| 68 | greg | 1.5 | DATARRAY  *dp;          /* data array for PDATA, MDATA or TDATA */ | 
| 69 | greg | 2.6 | COLOR  mcolor;          /* material (or pattern) color */ | 
| 70 |  |  | COLOR  rdiff;           /* diffuse reflection */ | 
| 71 |  |  | COLOR  tdiff;           /* diffuse transmission */ | 
| 72 |  |  | double  rspec;          /* specular reflectance (1 for BRDTF) */ | 
| 73 |  |  | double  trans;          /* transmissivity (.5 for BRDTF) */ | 
| 74 |  |  | double  tspec;          /* specular transmittance (1 for BRDTF) */ | 
| 75 | greg | 1.1 | FVECT  pnorm;           /* perturbed surface normal */ | 
| 76 |  |  | double  pdot;           /* perturbed dot product */ | 
| 77 |  |  | }  BRDFDAT;             /* BRDF material data */ | 
| 78 |  |  |  | 
| 79 |  |  |  | 
| 80 | greg | 2.15 | static void | 
| 81 | greg | 1.1 | dirbrdf(cval, np, ldir, omega)          /* compute source contribution */ | 
| 82 |  |  | COLOR  cval;                    /* returned coefficient */ | 
| 83 |  |  | register BRDFDAT  *np;          /* material data */ | 
| 84 |  |  | FVECT  ldir;                    /* light source direction */ | 
| 85 |  |  | double  omega;                  /* light source size */ | 
| 86 |  |  | { | 
| 87 |  |  | double  ldot; | 
| 88 |  |  | double  dtmp; | 
| 89 |  |  | COLOR  ctmp; | 
| 90 | greg | 1.4 | FVECT  ldx; | 
| 91 | greg | 2.12 | static double  vldx[5], pt[MAXDIM]; | 
| 92 | greg | 1.5 | register char   **sa; | 
| 93 | greg | 1.1 | register int    i; | 
| 94 | greg | 2.12 | #define lddx (vldx+1) | 
| 95 | greg | 1.1 |  | 
| 96 |  |  | setcolor(cval, 0.0, 0.0, 0.0); | 
| 97 |  |  |  | 
| 98 |  |  | ldot = DOT(np->pnorm, ldir); | 
| 99 |  |  |  | 
| 100 | greg | 1.5 | if (ldot <= FTINY && ldot >= -FTINY) | 
| 101 |  |  | return;         /* too close to grazing */ | 
| 102 | greg | 2.6 |  | 
| 103 | greg | 1.5 | if (ldot < 0.0 ? np->trans <= FTINY : np->trans >= 1.0-FTINY) | 
| 104 | greg | 1.1 | return;         /* wrong side */ | 
| 105 |  |  |  | 
| 106 | greg | 2.6 | if (ldot > 0.0) { | 
| 107 | greg | 1.1 | /* | 
| 108 |  |  | *  Compute and add diffuse reflected component to returned | 
| 109 |  |  | *  color.  The diffuse reflected component will always be | 
| 110 |  |  | *  modified by the color of the material. | 
| 111 |  |  | */ | 
| 112 | greg | 2.6 | copycolor(ctmp, np->rdiff); | 
| 113 |  |  | dtmp = ldot * omega / PI; | 
| 114 | greg | 1.1 | scalecolor(ctmp, dtmp); | 
| 115 |  |  | addcolor(cval, ctmp); | 
| 116 | greg | 2.6 | } else { | 
| 117 | greg | 1.1 | /* | 
| 118 | greg | 1.5 | *  Diffuse transmitted component. | 
| 119 | greg | 1.1 | */ | 
| 120 | greg | 2.6 | copycolor(ctmp, np->tdiff); | 
| 121 |  |  | dtmp = -ldot * omega / PI; | 
| 122 | greg | 1.5 | scalecolor(ctmp, dtmp); | 
| 123 |  |  | addcolor(cval, ctmp); | 
| 124 | greg | 1.1 | } | 
| 125 | greg | 1.5 | if (ldot > 0.0 ? np->rspec <= FTINY : np->tspec <= FTINY) | 
| 126 |  |  | return;         /* no specular component */ | 
| 127 |  |  | /* set up function */ | 
| 128 | greg | 1.10 | setbrdfunc(np); | 
| 129 | greg | 1.5 | sa = np->mp->oargs.sarg; | 
| 130 |  |  | errno = 0; | 
| 131 |  |  | /* transform light vector */ | 
| 132 |  |  | multv3(ldx, ldir, funcxf.xfm); | 
| 133 |  |  | for (i = 0; i < 3; i++) | 
| 134 | greg | 2.3 | lddx[i] = ldx[i]/funcxf.sca; | 
| 135 | greg | 2.12 | lddx[3] = omega; | 
| 136 | greg | 1.5 | /* compute BRTDF */ | 
| 137 |  |  | if (np->mp->otype == MAT_BRTDF) { | 
| 138 | greg | 2.6 | if (sa[6][0] == '0')            /* special case */ | 
| 139 |  |  | colval(ctmp,RED) = 0.0; | 
| 140 |  |  | else | 
| 141 | greg | 2.12 | colval(ctmp,RED) = funvalue(sa[6], 4, lddx); | 
| 142 | greg | 1.7 | if (!strcmp(sa[7],sa[6])) | 
| 143 | greg | 1.5 | colval(ctmp,GRN) = colval(ctmp,RED); | 
| 144 |  |  | else | 
| 145 | greg | 2.12 | colval(ctmp,GRN) = funvalue(sa[7], 4, lddx); | 
| 146 | greg | 1.7 | if (!strcmp(sa[8],sa[6])) | 
| 147 | greg | 1.5 | colval(ctmp,BLU) = colval(ctmp,RED); | 
| 148 | greg | 1.7 | else if (!strcmp(sa[8],sa[7])) | 
| 149 | greg | 1.5 | colval(ctmp,BLU) = colval(ctmp,GRN); | 
| 150 |  |  | else | 
| 151 | greg | 2.12 | colval(ctmp,BLU) = funvalue(sa[8], 4, lddx); | 
| 152 | greg | 1.5 | dtmp = bright(ctmp); | 
| 153 |  |  | } else if (np->dp == NULL) { | 
| 154 | greg | 2.12 | dtmp = funvalue(sa[0], 4, lddx); | 
| 155 | greg | 1.5 | setcolor(ctmp, dtmp, dtmp, dtmp); | 
| 156 |  |  | } else { | 
| 157 |  |  | for (i = 0; i < np->dp->nd; i++) | 
| 158 | greg | 2.12 | pt[i] = funvalue(sa[3+i], 4, lddx); | 
| 159 | greg | 2.7 | vldx[0] = datavalue(np->dp, pt); | 
| 160 | greg | 2.12 | dtmp = funvalue(sa[0], 5, vldx); | 
| 161 | greg | 1.5 | setcolor(ctmp, dtmp, dtmp, dtmp); | 
| 162 |  |  | } | 
| 163 | greg | 2.18 | if (errno == EDOM || errno == ERANGE) { | 
| 164 | greg | 2.2 | objerror(np->mp, WARNING, "compute error"); | 
| 165 |  |  | return; | 
| 166 |  |  | } | 
| 167 | greg | 1.5 | if (dtmp <= FTINY) | 
| 168 |  |  | return; | 
| 169 |  |  | if (ldot > 0.0) { | 
| 170 |  |  | /* | 
| 171 |  |  | *  Compute reflected non-diffuse component. | 
| 172 |  |  | */ | 
| 173 | schorsch | 2.19 | if ((np->mp->otype == MAT_MFUNC) | (np->mp->otype == MAT_MDATA)) | 
| 174 | greg | 1.6 | multcolor(ctmp, np->mcolor); | 
| 175 |  |  | dtmp = ldot * omega * np->rspec; | 
| 176 | greg | 1.5 | scalecolor(ctmp, dtmp); | 
| 177 |  |  | addcolor(cval, ctmp); | 
| 178 |  |  | } else { | 
| 179 |  |  | /* | 
| 180 |  |  | *  Compute transmitted non-diffuse component. | 
| 181 |  |  | */ | 
| 182 | schorsch | 2.19 | if ((np->mp->otype == MAT_TFUNC) | (np->mp->otype == MAT_TDATA)) | 
| 183 | greg | 1.6 | multcolor(ctmp, np->mcolor); | 
| 184 | greg | 1.5 | dtmp = -ldot * omega * np->tspec; | 
| 185 |  |  | scalecolor(ctmp, dtmp); | 
| 186 |  |  | addcolor(cval, ctmp); | 
| 187 |  |  | } | 
| 188 | greg | 2.12 | #undef lddx | 
| 189 | greg | 1.1 | } | 
| 190 |  |  |  | 
| 191 |  |  |  | 
| 192 | greg | 2.15 | int | 
| 193 |  |  | m_brdf(m, r)                    /* color a ray that hit a BRDTfunc material */ | 
| 194 | greg | 1.1 | register OBJREC  *m; | 
| 195 |  |  | register RAY  *r; | 
| 196 |  |  | { | 
| 197 | greg | 2.15 | int  hitfront = 1; | 
| 198 | greg | 1.1 | BRDFDAT  nd; | 
| 199 | greg | 2.6 | RAY  sr; | 
| 200 | greg | 1.7 | double  transtest, transdist; | 
| 201 | greg | 2.6 | int  hasrefl, hastrans; | 
| 202 | greg | 1.1 | COLOR  ctmp; | 
| 203 | greg | 2.14 | FVECT  vtmp; | 
| 204 | greg | 2.6 | register MFUNC  *mf; | 
| 205 | greg | 1.1 | register int  i; | 
| 206 | greg | 1.5 | /* check arguments */ | 
| 207 | schorsch | 2.19 | if ((m->oargs.nsargs < 10) | (m->oargs.nfargs < 9)) | 
| 208 | greg | 2.6 | objerror(m, USER, "bad # arguments"); | 
| 209 |  |  | nd.mp = m; | 
| 210 |  |  | nd.pr = r; | 
| 211 |  |  | /* dummy values */ | 
| 212 |  |  | nd.rspec = nd.tspec = 1.0; | 
| 213 |  |  | nd.trans = 0.5; | 
| 214 |  |  | /* diffuse reflectance */ | 
| 215 |  |  | if (r->rod > 0.0) | 
| 216 |  |  | setcolor(nd.rdiff, m->oargs.farg[0], | 
| 217 |  |  | m->oargs.farg[1], | 
| 218 |  |  | m->oargs.farg[2]); | 
| 219 |  |  | else | 
| 220 |  |  | setcolor(nd.rdiff, m->oargs.farg[3], | 
| 221 |  |  | m->oargs.farg[4], | 
| 222 |  |  | m->oargs.farg[5]); | 
| 223 |  |  | /* diffuse transmittance */ | 
| 224 |  |  | setcolor(nd.tdiff, m->oargs.farg[6], | 
| 225 |  |  | m->oargs.farg[7], | 
| 226 |  |  | m->oargs.farg[8]); | 
| 227 | greg | 2.17 | /* get modifiers */ | 
| 228 | greg | 2.6 | raytexture(r, m->omod); | 
| 229 |  |  | nd.pdot = raynormal(nd.pnorm, r);       /* perturb normal */ | 
| 230 |  |  | if (r->rod < 0.0) {                     /* orient perturbed values */ | 
| 231 |  |  | nd.pdot = -nd.pdot; | 
| 232 |  |  | for (i = 0; i < 3; i++) { | 
| 233 |  |  | nd.pnorm[i] = -nd.pnorm[i]; | 
| 234 |  |  | r->pert[i] = -r->pert[i]; | 
| 235 |  |  | } | 
| 236 | greg | 2.15 | hitfront = 0; | 
| 237 | greg | 1.5 | } | 
| 238 | greg | 2.6 | copycolor(nd.mcolor, r->pcol);          /* get pattern color */ | 
| 239 |  |  | multcolor(nd.rdiff, nd.mcolor);         /* modify diffuse values */ | 
| 240 |  |  | multcolor(nd.tdiff, nd.mcolor); | 
| 241 |  |  | hasrefl = bright(nd.rdiff) > FTINY; | 
| 242 |  |  | hastrans = bright(nd.tdiff) > FTINY; | 
| 243 |  |  | /* load cal file */ | 
| 244 |  |  | nd.dp = NULL; | 
| 245 |  |  | mf = getfunc(m, 9, 0x3f, 0); | 
| 246 |  |  | /* compute transmitted ray */ | 
| 247 |  |  | setbrdfunc(&nd); | 
| 248 |  |  | transtest = 0; | 
| 249 | greg | 2.8 | transdist = r->rot; | 
| 250 | greg | 2.6 | errno = 0; | 
| 251 |  |  | setcolor(ctmp, evalue(mf->ep[3]), | 
| 252 |  |  | evalue(mf->ep[4]), | 
| 253 |  |  | evalue(mf->ep[5])); | 
| 254 | greg | 2.18 | if (errno == EDOM || errno == ERANGE) | 
| 255 | greg | 2.6 | objerror(m, WARNING, "compute error"); | 
| 256 |  |  | else if (rayorigin(&sr, r, TRANS, bright(ctmp)) == 0) { | 
| 257 |  |  | if (!(r->crtype & SHADOW) && | 
| 258 |  |  | DOT(r->pert,r->pert) > FTINY*FTINY) { | 
| 259 |  |  | for (i = 0; i < 3; i++) /* perturb direction */ | 
| 260 |  |  | sr.rdir[i] = r->rdir[i] - .75*r->pert[i]; | 
| 261 |  |  | if (normalize(sr.rdir) == 0.0) { | 
| 262 |  |  | objerror(m, WARNING, "illegal perturbation"); | 
| 263 |  |  | VCOPY(sr.rdir, r->rdir); | 
| 264 |  |  | } | 
| 265 |  |  | } else { | 
| 266 |  |  | VCOPY(sr.rdir, r->rdir); | 
| 267 |  |  | transtest = 2; | 
| 268 |  |  | } | 
| 269 |  |  | rayvalue(&sr); | 
| 270 |  |  | multcolor(sr.rcol, ctmp); | 
| 271 |  |  | addcolor(r->rcol, sr.rcol); | 
| 272 |  |  | transtest *= bright(sr.rcol); | 
| 273 |  |  | transdist = r->rot + sr.rt; | 
| 274 |  |  | } | 
| 275 |  |  | if (r->crtype & SHADOW)                 /* the rest is shadow */ | 
| 276 | greg | 2.10 | return(1); | 
| 277 | greg | 2.6 | /* compute reflected ray */ | 
| 278 |  |  | setbrdfunc(&nd); | 
| 279 |  |  | errno = 0; | 
| 280 |  |  | setcolor(ctmp, evalue(mf->ep[0]), | 
| 281 |  |  | evalue(mf->ep[1]), | 
| 282 |  |  | evalue(mf->ep[2])); | 
| 283 | greg | 2.18 | if (errno == EDOM || errno == ERANGE) | 
| 284 | greg | 2.6 | objerror(m, WARNING, "compute error"); | 
| 285 |  |  | else if (rayorigin(&sr, r, REFLECTED, bright(ctmp)) == 0) { | 
| 286 |  |  | for (i = 0; i < 3; i++) | 
| 287 |  |  | sr.rdir[i] = r->rdir[i] + 2.0*nd.pdot*nd.pnorm[i]; | 
| 288 |  |  | rayvalue(&sr); | 
| 289 |  |  | multcolor(sr.rcol, ctmp); | 
| 290 |  |  | addcolor(r->rcol, sr.rcol); | 
| 291 |  |  | } | 
| 292 |  |  | /* compute ambient */ | 
| 293 |  |  | if (hasrefl) { | 
| 294 | greg | 2.15 | if (!hitfront) | 
| 295 | greg | 2.6 | flipsurface(r); | 
| 296 | greg | 2.15 | ambient(ctmp, r, nd.pnorm); | 
| 297 | greg | 2.6 | multcolor(ctmp, nd.rdiff); | 
| 298 |  |  | addcolor(r->rcol, ctmp);        /* add to returned color */ | 
| 299 | greg | 2.15 | if (!hitfront) | 
| 300 | greg | 2.6 | flipsurface(r); | 
| 301 |  |  | } | 
| 302 |  |  | if (hastrans) {                         /* from other side */ | 
| 303 | greg | 2.15 | if (hitfront) | 
| 304 | greg | 2.6 | flipsurface(r); | 
| 305 | greg | 2.15 | vtmp[0] = -nd.pnorm[0]; | 
| 306 |  |  | vtmp[1] = -nd.pnorm[1]; | 
| 307 |  |  | vtmp[2] = -nd.pnorm[2]; | 
| 308 | greg | 2.14 | ambient(ctmp, r, vtmp); | 
| 309 | greg | 2.6 | multcolor(ctmp, nd.tdiff); | 
| 310 |  |  | addcolor(r->rcol, ctmp); | 
| 311 | greg | 2.15 | if (hitfront) | 
| 312 | greg | 2.6 | flipsurface(r); | 
| 313 |  |  | } | 
| 314 |  |  | if (hasrefl | hastrans || m->oargs.sarg[6][0] != '0') | 
| 315 |  |  | direct(r, dirbrdf, &nd);        /* add direct component */ | 
| 316 |  |  | /* check distance */ | 
| 317 |  |  | if (transtest > bright(r->rcol)) | 
| 318 |  |  | r->rt = transdist; | 
| 319 | greg | 2.10 |  | 
| 320 |  |  | return(1); | 
| 321 | greg | 2.6 | } | 
| 322 |  |  |  | 
| 323 |  |  |  | 
| 324 |  |  |  | 
| 325 | greg | 2.15 | int | 
| 326 |  |  | m_brdf2(m, r)                   /* color a ray that hit a BRDF material */ | 
| 327 | greg | 2.6 | register OBJREC  *m; | 
| 328 |  |  | register RAY  *r; | 
| 329 |  |  | { | 
| 330 |  |  | BRDFDAT  nd; | 
| 331 |  |  | COLOR  ctmp; | 
| 332 | greg | 2.14 | FVECT  vtmp; | 
| 333 | greg | 2.6 | double  dtmp; | 
| 334 |  |  | /* always a shadow */ | 
| 335 |  |  | if (r->crtype & SHADOW) | 
| 336 | greg | 2.10 | return(1); | 
| 337 | greg | 2.6 | /* check arguments */ | 
| 338 | schorsch | 2.19 | if ((m->oargs.nsargs < (hasdata(m->otype)?4:2)) | (m->oargs.nfargs < | 
| 339 |  |  | ((m->otype==MAT_TFUNC)|(m->otype==MAT_TDATA)?6:4))) | 
| 340 | greg | 1.1 | objerror(m, USER, "bad # arguments"); | 
| 341 | greg | 2.17 | /* check for back side */ | 
| 342 |  |  | if (r->rod < 0.0) { | 
| 343 |  |  | if (!backvis && m->otype != MAT_TFUNC | 
| 344 |  |  | && m->otype != MAT_TDATA) { | 
| 345 |  |  | raytrans(r); | 
| 346 |  |  | return(1); | 
| 347 |  |  | } | 
| 348 |  |  | raytexture(r, m->omod); | 
| 349 |  |  | flipsurface(r);                 /* reorient if backvis */ | 
| 350 |  |  | } else | 
| 351 |  |  | raytexture(r, m->omod); | 
| 352 |  |  |  | 
| 353 | greg | 1.1 | nd.mp = m; | 
| 354 |  |  | nd.pr = r; | 
| 355 | greg | 2.6 | /* get material color */ | 
| 356 |  |  | setcolor(nd.mcolor, m->oargs.farg[0], | 
| 357 |  |  | m->oargs.farg[1], | 
| 358 |  |  | m->oargs.farg[2]); | 
| 359 | greg | 1.5 | /* get specular component */ | 
| 360 |  |  | nd.rspec = m->oargs.farg[3]; | 
| 361 | greg | 2.6 | /* compute transmittance */ | 
| 362 | schorsch | 2.19 | if ((m->otype == MAT_TFUNC) | (m->otype == MAT_TDATA)) { | 
| 363 | greg | 1.5 | nd.trans = m->oargs.farg[4]*(1.0 - nd.rspec); | 
| 364 |  |  | nd.tspec = nd.trans * m->oargs.farg[5]; | 
| 365 | greg | 2.6 | dtmp = nd.trans - nd.tspec; | 
| 366 |  |  | setcolor(nd.tdiff, dtmp, dtmp, dtmp); | 
| 367 |  |  | } else { | 
| 368 |  |  | nd.tspec = nd.trans = 0.0; | 
| 369 |  |  | setcolor(nd.tdiff, 0.0, 0.0, 0.0); | 
| 370 |  |  | } | 
| 371 |  |  | /* compute reflectance */ | 
| 372 |  |  | dtmp = 1.0 - nd.trans - nd.rspec; | 
| 373 |  |  | setcolor(nd.rdiff, dtmp, dtmp, dtmp); | 
| 374 | greg | 1.5 | nd.pdot = raynormal(nd.pnorm, r);       /* perturb normal */ | 
| 375 |  |  | multcolor(nd.mcolor, r->pcol);          /* modify material color */ | 
| 376 | greg | 2.6 | multcolor(nd.rdiff, nd.mcolor); | 
| 377 |  |  | multcolor(nd.tdiff, nd.mcolor); | 
| 378 | greg | 1.1 | /* load auxiliary files */ | 
| 379 | greg | 2.2 | if (hasdata(m->otype)) { | 
| 380 | greg | 1.1 | nd.dp = getdata(m->oargs.sarg[1]); | 
| 381 | greg | 2.6 | getfunc(m, 2, 0, 0); | 
| 382 | greg | 1.1 | } else { | 
| 383 |  |  | nd.dp = NULL; | 
| 384 | greg | 2.6 | getfunc(m, 1, 0, 0); | 
| 385 | greg | 1.1 | } | 
| 386 |  |  | /* compute ambient */ | 
| 387 | greg | 2.6 | if (nd.trans < 1.0-FTINY) { | 
| 388 | greg | 2.13 | ambient(ctmp, r, nd.pnorm); | 
| 389 | greg | 2.6 | scalecolor(ctmp, 1.0-nd.trans); | 
| 390 | greg | 1.1 | multcolor(ctmp, nd.mcolor);     /* modified by material color */ | 
| 391 |  |  | addcolor(r->rcol, ctmp);        /* add to returned color */ | 
| 392 | greg | 1.5 | } | 
| 393 | greg | 2.6 | if (nd.trans > FTINY) {         /* from other side */ | 
| 394 | greg | 1.5 | flipsurface(r); | 
| 395 | greg | 2.14 | vtmp[0] = -nd.pnorm[0]; | 
| 396 |  |  | vtmp[1] = -nd.pnorm[1]; | 
| 397 |  |  | vtmp[2] = -nd.pnorm[2]; | 
| 398 |  |  | ambient(ctmp, r, vtmp); | 
| 399 | greg | 2.6 | scalecolor(ctmp, nd.trans); | 
| 400 | greg | 1.5 | multcolor(ctmp, nd.mcolor); | 
| 401 |  |  | addcolor(r->rcol, ctmp); | 
| 402 |  |  | flipsurface(r); | 
| 403 | greg | 1.1 | } | 
| 404 |  |  | /* add direct component */ | 
| 405 |  |  | direct(r, dirbrdf, &nd); | 
| 406 | greg | 2.10 |  | 
| 407 |  |  | return(1); | 
| 408 | greg | 1.10 | } | 
| 409 |  |  |  | 
| 410 |  |  |  | 
| 411 | greg | 2.15 | int | 
| 412 | greg | 1.10 | setbrdfunc(np)                  /* set up brdf function and variables */ | 
| 413 |  |  | register BRDFDAT  *np; | 
| 414 |  |  | { | 
| 415 |  |  | FVECT  vec; | 
| 416 |  |  |  | 
| 417 |  |  | if (setfunc(np->mp, np->pr) == 0) | 
| 418 |  |  | return(0);      /* it's OK, setfunc says we're done */ | 
| 419 |  |  | /* else (re)assign special variables */ | 
| 420 |  |  | multv3(vec, np->pnorm, funcxf.xfm); | 
| 421 |  |  | varset("NxP", '=', vec[0]/funcxf.sca); | 
| 422 |  |  | varset("NyP", '=', vec[1]/funcxf.sca); | 
| 423 |  |  | varset("NzP", '=', vec[2]/funcxf.sca); | 
| 424 | greg | 1.11 | varset("RdotP", '=', np->pdot <= -1.0 ? -1.0 : | 
| 425 |  |  | np->pdot >= 1.0 ? 1.0 : np->pdot); | 
| 426 | greg | 1.10 | varset("CrP", '=', colval(np->mcolor,RED)); | 
| 427 |  |  | varset("CgP", '=', colval(np->mcolor,GRN)); | 
| 428 |  |  | varset("CbP", '=', colval(np->mcolor,BLU)); | 
| 429 |  |  | return(1); | 
| 430 | greg | 1.1 | } |