| 1 |
greg |
1.1 |
#ifndef lint |
| 2 |
greg |
2.41 |
static const char RCSid[] = "$Id: m_brdf.c,v 2.40 2023/11/15 18:02:52 greg Exp $"; |
| 3 |
greg |
1.1 |
#endif |
| 4 |
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/* |
| 5 |
|
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* Shading for materials with arbitrary BRDF's |
| 6 |
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*/ |
| 7 |
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|
| 8 |
greg |
2.16 |
#include "copyright.h" |
| 9 |
greg |
2.15 |
|
| 10 |
greg |
1.1 |
#include "ray.h" |
| 11 |
greg |
2.20 |
#include "ambient.h" |
| 12 |
greg |
1.1 |
#include "data.h" |
| 13 |
schorsch |
2.21 |
#include "source.h" |
| 14 |
greg |
1.1 |
#include "otypes.h" |
| 15 |
schorsch |
2.21 |
#include "rtotypes.h" |
| 16 |
greg |
2.2 |
#include "func.h" |
| 17 |
greg |
2.33 |
#include "pmapmat.h" |
| 18 |
greg |
2.2 |
|
| 19 |
greg |
1.1 |
/* |
| 20 |
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* Arguments to this material include the color and specularity. |
| 21 |
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* String arguments include the reflection function and files. |
| 22 |
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* The BRDF is currently used just for the specular component to light |
| 23 |
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* sources. Reflectance values or data coordinates are functions |
| 24 |
greg |
2.7 |
* of the direction to the light source. (Data modification functions |
| 25 |
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* are passed the source direction as args 2-4.) |
| 26 |
greg |
1.1 |
* 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_PFUNC and MAT_MFUNC are: |
| 30 |
greg |
1.4 |
* 2+ func funcfile transform |
| 31 |
greg |
1.1 |
* 0 |
| 32 |
greg |
1.4 |
* 4+ red grn blu specularity A5 .. |
| 33 |
greg |
1.1 |
* |
| 34 |
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* Arguments for MAT_PDATA and MAT_MDATA are: |
| 35 |
greg |
1.4 |
* 4+ func datafile funcfile v0 .. transform |
| 36 |
greg |
1.1 |
* 0 |
| 37 |
greg |
1.4 |
* 4+ red grn blu specularity A5 .. |
| 38 |
greg |
1.5 |
* |
| 39 |
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* Arguments for MAT_TFUNC are: |
| 40 |
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* 2+ func funcfile transform |
| 41 |
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* 0 |
| 42 |
greg |
2.29 |
* 6+ red grn blu rspec trans tspec A7 .. |
| 43 |
greg |
1.5 |
* |
| 44 |
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* Arguments for MAT_TDATA are: |
| 45 |
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* 4+ func datafile funcfile v0 .. transform |
| 46 |
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* 0 |
| 47 |
greg |
2.29 |
* 6+ red grn blu rspec trans tspec A7 .. |
| 48 |
greg |
1.5 |
* |
| 49 |
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* Arguments for the more general MAT_BRTDF are: |
| 50 |
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* 10+ rrefl grefl brefl |
| 51 |
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* rtrns gtrns btrns |
| 52 |
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* rbrtd gbrtd bbrtd |
| 53 |
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* funcfile transform |
| 54 |
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* 0 |
| 55 |
greg |
2.6 |
* 9+ rdf gdf bdf |
| 56 |
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* rdb gdb bdb |
| 57 |
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* rdt gdt bdt A10 .. |
| 58 |
greg |
1.5 |
* |
| 59 |
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* In addition to the normal variables available to functions, |
| 60 |
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* we define the following: |
| 61 |
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* NxP, NyP, NzP - perturbed surface normal |
| 62 |
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* RdotP - perturbed ray dot product |
| 63 |
greg |
2.6 |
* CrP, CgP, CbP - perturbed material color (or pattern) |
| 64 |
greg |
1.1 |
*/ |
| 65 |
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| 66 |
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typedef struct { |
| 67 |
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OBJREC *mp; /* material pointer */ |
| 68 |
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RAY *pr; /* intersected ray */ |
| 69 |
greg |
1.5 |
DATARRAY *dp; /* data array for PDATA, MDATA or TDATA */ |
| 70 |
greg |
2.40 |
SCOLOR mcolor; /* material (or pattern) color */ |
| 71 |
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SCOLOR rdiff; /* diffuse reflection */ |
| 72 |
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SCOLOR tdiff; /* diffuse transmission */ |
| 73 |
greg |
2.6 |
double rspec; /* specular reflectance (1 for BRDTF) */ |
| 74 |
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double trans; /* transmissivity (.5 for BRDTF) */ |
| 75 |
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double tspec; /* specular transmittance (1 for BRDTF) */ |
| 76 |
greg |
1.1 |
FVECT pnorm; /* perturbed surface normal */ |
| 77 |
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double pdot; /* perturbed dot product */ |
| 78 |
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} BRDFDAT; /* BRDF material data */ |
| 79 |
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| 80 |
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| 81 |
greg |
2.28 |
static int setbrdfunc(BRDFDAT *np); |
| 82 |
schorsch |
2.21 |
|
| 83 |
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|
| 84 |
greg |
2.15 |
static void |
| 85 |
schorsch |
2.21 |
dirbrdf( /* compute source contribution */ |
| 86 |
greg |
2.40 |
SCOLOR scval, /* returned coefficient */ |
| 87 |
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void *nnp, /* material data */ |
| 88 |
schorsch |
2.21 |
FVECT ldir, /* light source direction */ |
| 89 |
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double omega /* light source size */ |
| 90 |
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) |
| 91 |
greg |
1.1 |
{ |
| 92 |
greg |
2.28 |
BRDFDAT *np = nnp; |
| 93 |
greg |
1.1 |
double ldot; |
| 94 |
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double dtmp; |
| 95 |
greg |
2.40 |
SCOLOR sctmp; |
| 96 |
greg |
1.1 |
COLOR ctmp; |
| 97 |
greg |
1.4 |
FVECT ldx; |
| 98 |
greg |
2.40 |
static double vldx[5], pt[MAXDDIM]; |
| 99 |
greg |
2.28 |
char **sa; |
| 100 |
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int i; |
| 101 |
greg |
2.12 |
#define lddx (vldx+1) |
| 102 |
greg |
1.1 |
|
| 103 |
greg |
2.40 |
scolorblack(scval); |
| 104 |
greg |
1.1 |
|
| 105 |
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ldot = DOT(np->pnorm, ldir); |
| 106 |
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|
| 107 |
greg |
1.5 |
if (ldot <= FTINY && ldot >= -FTINY) |
| 108 |
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return; /* too close to grazing */ |
| 109 |
greg |
2.6 |
|
| 110 |
greg |
1.5 |
if (ldot < 0.0 ? np->trans <= FTINY : np->trans >= 1.0-FTINY) |
| 111 |
greg |
1.1 |
return; /* wrong side */ |
| 112 |
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|
| 113 |
greg |
2.6 |
if (ldot > 0.0) { |
| 114 |
greg |
1.1 |
/* |
| 115 |
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* Compute and add diffuse reflected component to returned |
| 116 |
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* color. The diffuse reflected component will always be |
| 117 |
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* modified by the color of the material. |
| 118 |
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*/ |
| 119 |
greg |
2.40 |
copyscolor(sctmp, np->rdiff); |
| 120 |
greg |
2.6 |
dtmp = ldot * omega / PI; |
| 121 |
greg |
2.40 |
scalescolor(sctmp, dtmp); |
| 122 |
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saddscolor(scval, sctmp); |
| 123 |
greg |
2.6 |
} else { |
| 124 |
greg |
1.1 |
/* |
| 125 |
greg |
1.5 |
* Diffuse transmitted component. |
| 126 |
greg |
1.1 |
*/ |
| 127 |
greg |
2.40 |
copyscolor(sctmp, np->tdiff); |
| 128 |
greg |
2.6 |
dtmp = -ldot * omega / PI; |
| 129 |
greg |
2.40 |
scalescolor(sctmp, dtmp); |
| 130 |
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saddscolor(scval, sctmp); |
| 131 |
greg |
1.1 |
} |
| 132 |
greg |
2.33 |
if ((ldot > 0.0 ? np->rspec <= FTINY : np->tspec <= FTINY) || |
| 133 |
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ambRayInPmap(np->pr)) |
| 134 |
greg |
2.24 |
return; /* diffuse only */ |
| 135 |
greg |
1.5 |
/* set up function */ |
| 136 |
greg |
1.10 |
setbrdfunc(np); |
| 137 |
greg |
1.5 |
sa = np->mp->oargs.sarg; |
| 138 |
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errno = 0; |
| 139 |
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/* transform light vector */ |
| 140 |
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multv3(ldx, ldir, funcxf.xfm); |
| 141 |
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for (i = 0; i < 3; i++) |
| 142 |
greg |
2.3 |
lddx[i] = ldx[i]/funcxf.sca; |
| 143 |
greg |
2.12 |
lddx[3] = omega; |
| 144 |
greg |
1.5 |
/* compute BRTDF */ |
| 145 |
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if (np->mp->otype == MAT_BRTDF) { |
| 146 |
greg |
2.32 |
if (sa[6][0] == '0' && !sa[6][1]) /* special case */ |
| 147 |
greg |
2.6 |
colval(ctmp,RED) = 0.0; |
| 148 |
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else |
| 149 |
greg |
2.12 |
colval(ctmp,RED) = funvalue(sa[6], 4, lddx); |
| 150 |
greg |
2.32 |
if (sa[7][0] == '0' && !sa[7][1]) |
| 151 |
greg |
2.24 |
colval(ctmp,GRN) = 0.0; |
| 152 |
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else if (!strcmp(sa[7],sa[6])) |
| 153 |
greg |
1.5 |
colval(ctmp,GRN) = colval(ctmp,RED); |
| 154 |
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else |
| 155 |
greg |
2.12 |
colval(ctmp,GRN) = funvalue(sa[7], 4, lddx); |
| 156 |
greg |
2.32 |
if (sa[8][0] == '0' && !sa[8][1]) |
| 157 |
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colval(ctmp,BLU) = 0.0; |
| 158 |
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else if (!strcmp(sa[8],sa[6])) |
| 159 |
greg |
1.5 |
colval(ctmp,BLU) = colval(ctmp,RED); |
| 160 |
greg |
1.7 |
else if (!strcmp(sa[8],sa[7])) |
| 161 |
greg |
1.5 |
colval(ctmp,BLU) = colval(ctmp,GRN); |
| 162 |
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else |
| 163 |
greg |
2.12 |
colval(ctmp,BLU) = funvalue(sa[8], 4, lddx); |
| 164 |
greg |
1.5 |
dtmp = bright(ctmp); |
| 165 |
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} else if (np->dp == NULL) { |
| 166 |
greg |
2.12 |
dtmp = funvalue(sa[0], 4, lddx); |
| 167 |
greg |
1.5 |
setcolor(ctmp, dtmp, dtmp, dtmp); |
| 168 |
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} else { |
| 169 |
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for (i = 0; i < np->dp->nd; i++) |
| 170 |
greg |
2.12 |
pt[i] = funvalue(sa[3+i], 4, lddx); |
| 171 |
greg |
2.7 |
vldx[0] = datavalue(np->dp, pt); |
| 172 |
greg |
2.12 |
dtmp = funvalue(sa[0], 5, vldx); |
| 173 |
greg |
1.5 |
setcolor(ctmp, dtmp, dtmp, dtmp); |
| 174 |
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} |
| 175 |
greg |
2.25 |
if ((errno == EDOM) | (errno == ERANGE)) { |
| 176 |
greg |
2.2 |
objerror(np->mp, WARNING, "compute error"); |
| 177 |
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return; |
| 178 |
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} |
| 179 |
greg |
1.5 |
if (dtmp <= FTINY) |
| 180 |
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return; |
| 181 |
greg |
2.40 |
setscolor(sctmp, colval(ctmp,RED), colval(ctmp,GRN), colval(ctmp,BLU)); |
| 182 |
greg |
1.5 |
if (ldot > 0.0) { |
| 183 |
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/* |
| 184 |
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* Compute reflected non-diffuse component. |
| 185 |
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*/ |
| 186 |
schorsch |
2.19 |
if ((np->mp->otype == MAT_MFUNC) | (np->mp->otype == MAT_MDATA)) |
| 187 |
greg |
2.40 |
smultscolor(sctmp, np->mcolor); |
| 188 |
greg |
1.6 |
dtmp = ldot * omega * np->rspec; |
| 189 |
greg |
2.40 |
scalescolor(sctmp, dtmp); |
| 190 |
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saddscolor(scval, sctmp); |
| 191 |
greg |
1.5 |
} else { |
| 192 |
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/* |
| 193 |
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* Compute transmitted non-diffuse component. |
| 194 |
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*/ |
| 195 |
schorsch |
2.19 |
if ((np->mp->otype == MAT_TFUNC) | (np->mp->otype == MAT_TDATA)) |
| 196 |
greg |
2.40 |
smultscolor(sctmp, np->mcolor); |
| 197 |
greg |
1.5 |
dtmp = -ldot * omega * np->tspec; |
| 198 |
greg |
2.40 |
scalescolor(sctmp, dtmp); |
| 199 |
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saddscolor(scval, sctmp); |
| 200 |
greg |
1.5 |
} |
| 201 |
greg |
2.12 |
#undef lddx |
| 202 |
greg |
1.1 |
} |
| 203 |
|
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|
| 204 |
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|
| 205 |
greg |
2.28 |
int |
| 206 |
schorsch |
2.21 |
m_brdf( /* color a ray that hit a BRDTfunc material */ |
| 207 |
greg |
2.28 |
OBJREC *m, |
| 208 |
|
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RAY *r |
| 209 |
schorsch |
2.21 |
) |
| 210 |
greg |
1.1 |
{ |
| 211 |
greg |
2.15 |
int hitfront = 1; |
| 212 |
greg |
1.1 |
BRDFDAT nd; |
| 213 |
greg |
2.6 |
RAY sr; |
| 214 |
|
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int hasrefl, hastrans; |
| 215 |
greg |
2.22 |
int hastexture; |
| 216 |
greg |
2.40 |
SCOLOR sctmp; |
| 217 |
greg |
2.14 |
FVECT vtmp; |
| 218 |
greg |
2.22 |
double d; |
| 219 |
greg |
2.28 |
MFUNC *mf; |
| 220 |
|
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int i; |
| 221 |
greg |
1.5 |
/* check arguments */ |
| 222 |
schorsch |
2.19 |
if ((m->oargs.nsargs < 10) | (m->oargs.nfargs < 9)) |
| 223 |
greg |
2.6 |
objerror(m, USER, "bad # arguments"); |
| 224 |
|
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nd.mp = m; |
| 225 |
|
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nd.pr = r; |
| 226 |
|
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/* dummy values */ |
| 227 |
|
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nd.rspec = nd.tspec = 1.0; |
| 228 |
|
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nd.trans = 0.5; |
| 229 |
|
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/* diffuse reflectance */ |
| 230 |
|
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if (r->rod > 0.0) |
| 231 |
greg |
2.40 |
setscolor(nd.rdiff, m->oargs.farg[0], |
| 232 |
greg |
2.6 |
m->oargs.farg[1], |
| 233 |
|
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m->oargs.farg[2]); |
| 234 |
|
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else |
| 235 |
greg |
2.40 |
setscolor(nd.rdiff, m->oargs.farg[3], |
| 236 |
greg |
2.6 |
m->oargs.farg[4], |
| 237 |
|
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m->oargs.farg[5]); |
| 238 |
|
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/* diffuse transmittance */ |
| 239 |
greg |
2.40 |
setscolor(nd.tdiff, m->oargs.farg[6], |
| 240 |
greg |
2.6 |
m->oargs.farg[7], |
| 241 |
|
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m->oargs.farg[8]); |
| 242 |
greg |
2.17 |
/* get modifiers */ |
| 243 |
greg |
2.6 |
raytexture(r, m->omod); |
| 244 |
greg |
2.34 |
hastexture = (DOT(r->pert,r->pert) > FTINY*FTINY); |
| 245 |
greg |
2.22 |
if (hastexture) { /* perturb normal */ |
| 246 |
|
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nd.pdot = raynormal(nd.pnorm, r); |
| 247 |
|
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} else { |
| 248 |
|
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VCOPY(nd.pnorm, r->ron); |
| 249 |
|
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nd.pdot = r->rod; |
| 250 |
|
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} |
| 251 |
greg |
2.6 |
if (r->rod < 0.0) { /* orient perturbed values */ |
| 252 |
|
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nd.pdot = -nd.pdot; |
| 253 |
|
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for (i = 0; i < 3; i++) { |
| 254 |
|
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nd.pnorm[i] = -nd.pnorm[i]; |
| 255 |
|
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r->pert[i] = -r->pert[i]; |
| 256 |
|
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} |
| 257 |
greg |
2.15 |
hitfront = 0; |
| 258 |
greg |
1.5 |
} |
| 259 |
greg |
2.40 |
copyscolor(nd.mcolor, r->pcol); /* get pattern color */ |
| 260 |
|
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smultscolor(nd.rdiff, nd.mcolor); /* modify diffuse values */ |
| 261 |
|
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smultscolor(nd.tdiff, nd.mcolor); |
| 262 |
|
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hasrefl = (sintens(nd.rdiff) > FTINY); |
| 263 |
|
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hastrans = (sintens(nd.tdiff) > FTINY); |
| 264 |
greg |
2.6 |
/* load cal file */ |
| 265 |
|
|
nd.dp = NULL; |
| 266 |
|
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mf = getfunc(m, 9, 0x3f, 0); |
| 267 |
|
|
/* compute transmitted ray */ |
| 268 |
|
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setbrdfunc(&nd); |
| 269 |
|
|
errno = 0; |
| 270 |
greg |
2.40 |
setscolor(sctmp, evalue(mf->ep[3]), |
| 271 |
greg |
2.6 |
evalue(mf->ep[4]), |
| 272 |
|
|
evalue(mf->ep[5])); |
| 273 |
greg |
2.25 |
if ((errno == EDOM) | (errno == ERANGE)) |
| 274 |
greg |
2.6 |
objerror(m, WARNING, "compute error"); |
| 275 |
greg |
2.40 |
else if (rayorigin(&sr, TRANS, r, sctmp) == 0) { |
| 276 |
greg |
2.34 |
if (hastexture && !(r->crtype & (SHADOW|AMBIENT))) { |
| 277 |
greg |
2.27 |
/* perturb direction */ |
| 278 |
greg |
2.34 |
VSUB(sr.rdir, r->rdir, r->pert); |
| 279 |
greg |
2.6 |
if (normalize(sr.rdir) == 0.0) { |
| 280 |
|
|
objerror(m, WARNING, "illegal perturbation"); |
| 281 |
|
|
VCOPY(sr.rdir, r->rdir); |
| 282 |
|
|
} |
| 283 |
|
|
} else { |
| 284 |
|
|
VCOPY(sr.rdir, r->rdir); |
| 285 |
|
|
} |
| 286 |
|
|
rayvalue(&sr); |
| 287 |
greg |
2.40 |
smultscolor(sr.rcol, sr.rcoef); |
| 288 |
|
|
saddscolor(r->rcol, sr.rcol); |
| 289 |
greg |
2.38 |
if ((!hastexture || r->crtype & (SHADOW|AMBIENT)) && |
| 290 |
greg |
2.40 |
nd.tspec > pbright(nd.tdiff) + pbright(nd.rdiff)) |
| 291 |
greg |
2.36 |
r->rxt = r->rot + raydistance(&sr); |
| 292 |
greg |
2.6 |
} |
| 293 |
greg |
2.36 |
if (r->crtype & SHADOW) /* the rest is shadow */ |
| 294 |
greg |
2.10 |
return(1); |
| 295 |
greg |
2.36 |
|
| 296 |
greg |
2.6 |
/* compute reflected ray */ |
| 297 |
|
|
setbrdfunc(&nd); |
| 298 |
|
|
errno = 0; |
| 299 |
greg |
2.40 |
setscolor(sctmp, evalue(mf->ep[0]), |
| 300 |
greg |
2.6 |
evalue(mf->ep[1]), |
| 301 |
|
|
evalue(mf->ep[2])); |
| 302 |
greg |
2.25 |
if ((errno == EDOM) | (errno == ERANGE)) |
| 303 |
greg |
2.6 |
objerror(m, WARNING, "compute error"); |
| 304 |
greg |
2.40 |
else if (rayorigin(&sr, REFLECTED, r, sctmp) == 0) { |
| 305 |
greg |
2.27 |
VSUM(sr.rdir, r->rdir, nd.pnorm, 2.*nd.pdot); |
| 306 |
greg |
2.26 |
checknorm(sr.rdir); |
| 307 |
greg |
2.6 |
rayvalue(&sr); |
| 308 |
greg |
2.40 |
smultscolor(sr.rcol, sr.rcoef); |
| 309 |
|
|
copyscolor(r->mcol, sr.rcol); |
| 310 |
|
|
saddscolor(r->rcol, sr.rcol); |
| 311 |
greg |
2.39 |
r->rmt = r->rot; |
| 312 |
greg |
2.36 |
if (r->ro != NULL && isflat(r->ro->otype) && |
| 313 |
|
|
!hastexture | (r->crtype & AMBIENT)) |
| 314 |
greg |
2.39 |
r->rmt += raydistance(&sr); |
| 315 |
greg |
2.6 |
} |
| 316 |
|
|
/* compute ambient */ |
| 317 |
|
|
if (hasrefl) { |
| 318 |
greg |
2.40 |
copyscolor(sctmp, nd.rdiff); |
| 319 |
|
|
multambient(sctmp, r, nd.pnorm); |
| 320 |
|
|
saddscolor(r->rcol, sctmp); /* add to returned color */ |
| 321 |
greg |
2.6 |
} |
| 322 |
|
|
if (hastrans) { /* from other side */ |
| 323 |
greg |
2.15 |
vtmp[0] = -nd.pnorm[0]; |
| 324 |
|
|
vtmp[1] = -nd.pnorm[1]; |
| 325 |
|
|
vtmp[2] = -nd.pnorm[2]; |
| 326 |
greg |
2.40 |
copyscolor(sctmp, nd.tdiff); |
| 327 |
|
|
multambient(sctmp, r, vtmp); |
| 328 |
|
|
saddscolor(r->rcol, sctmp); |
| 329 |
greg |
2.6 |
} |
| 330 |
|
|
if (hasrefl | hastrans || m->oargs.sarg[6][0] != '0') |
| 331 |
|
|
direct(r, dirbrdf, &nd); /* add direct component */ |
| 332 |
greg |
2.22 |
|
| 333 |
greg |
2.10 |
return(1); |
| 334 |
greg |
2.6 |
} |
| 335 |
|
|
|
| 336 |
|
|
|
| 337 |
|
|
|
| 338 |
greg |
2.28 |
int |
| 339 |
schorsch |
2.21 |
m_brdf2( /* color a ray that hit a BRDF material */ |
| 340 |
greg |
2.28 |
OBJREC *m, |
| 341 |
|
|
RAY *r |
| 342 |
schorsch |
2.21 |
) |
| 343 |
greg |
2.6 |
{ |
| 344 |
|
|
BRDFDAT nd; |
| 345 |
greg |
2.40 |
SCOLOR sctmp; |
| 346 |
greg |
2.14 |
FVECT vtmp; |
| 347 |
greg |
2.6 |
double dtmp; |
| 348 |
|
|
/* always a shadow */ |
| 349 |
|
|
if (r->crtype & SHADOW) |
| 350 |
greg |
2.10 |
return(1); |
| 351 |
greg |
2.6 |
/* check arguments */ |
| 352 |
schorsch |
2.19 |
if ((m->oargs.nsargs < (hasdata(m->otype)?4:2)) | (m->oargs.nfargs < |
| 353 |
|
|
((m->otype==MAT_TFUNC)|(m->otype==MAT_TDATA)?6:4))) |
| 354 |
greg |
1.1 |
objerror(m, USER, "bad # arguments"); |
| 355 |
greg |
2.17 |
/* check for back side */ |
| 356 |
|
|
if (r->rod < 0.0) { |
| 357 |
greg |
2.31 |
if (!backvis) { |
| 358 |
greg |
2.17 |
raytrans(r); |
| 359 |
|
|
return(1); |
| 360 |
|
|
} |
| 361 |
|
|
raytexture(r, m->omod); |
| 362 |
|
|
flipsurface(r); /* reorient if backvis */ |
| 363 |
|
|
} else |
| 364 |
|
|
raytexture(r, m->omod); |
| 365 |
|
|
|
| 366 |
greg |
1.1 |
nd.mp = m; |
| 367 |
|
|
nd.pr = r; |
| 368 |
greg |
2.6 |
/* get material color */ |
| 369 |
greg |
2.40 |
setscolor(nd.mcolor, m->oargs.farg[0], |
| 370 |
greg |
2.6 |
m->oargs.farg[1], |
| 371 |
|
|
m->oargs.farg[2]); |
| 372 |
greg |
1.5 |
/* get specular component */ |
| 373 |
|
|
nd.rspec = m->oargs.farg[3]; |
| 374 |
greg |
2.6 |
/* compute transmittance */ |
| 375 |
schorsch |
2.19 |
if ((m->otype == MAT_TFUNC) | (m->otype == MAT_TDATA)) { |
| 376 |
greg |
1.5 |
nd.trans = m->oargs.farg[4]*(1.0 - nd.rspec); |
| 377 |
|
|
nd.tspec = nd.trans * m->oargs.farg[5]; |
| 378 |
greg |
2.6 |
dtmp = nd.trans - nd.tspec; |
| 379 |
greg |
2.40 |
setscolor(nd.tdiff, dtmp, dtmp, dtmp); |
| 380 |
greg |
2.6 |
} else { |
| 381 |
|
|
nd.tspec = nd.trans = 0.0; |
| 382 |
greg |
2.40 |
scolorblack(nd.tdiff); |
| 383 |
greg |
2.6 |
} |
| 384 |
|
|
/* compute reflectance */ |
| 385 |
|
|
dtmp = 1.0 - nd.trans - nd.rspec; |
| 386 |
greg |
2.40 |
setscolor(nd.rdiff, dtmp, dtmp, dtmp); |
| 387 |
greg |
1.5 |
nd.pdot = raynormal(nd.pnorm, r); /* perturb normal */ |
| 388 |
greg |
2.40 |
smultscolor(nd.mcolor, r->pcol); /* modify material color */ |
| 389 |
|
|
smultscolor(nd.rdiff, nd.mcolor); |
| 390 |
|
|
smultscolor(nd.tdiff, nd.mcolor); |
| 391 |
greg |
1.1 |
/* load auxiliary files */ |
| 392 |
greg |
2.2 |
if (hasdata(m->otype)) { |
| 393 |
greg |
1.1 |
nd.dp = getdata(m->oargs.sarg[1]); |
| 394 |
greg |
2.6 |
getfunc(m, 2, 0, 0); |
| 395 |
greg |
1.1 |
} else { |
| 396 |
|
|
nd.dp = NULL; |
| 397 |
greg |
2.6 |
getfunc(m, 1, 0, 0); |
| 398 |
greg |
1.1 |
} |
| 399 |
|
|
/* compute ambient */ |
| 400 |
greg |
2.6 |
if (nd.trans < 1.0-FTINY) { |
| 401 |
greg |
2.40 |
copyscolor(sctmp, nd.mcolor); /* modified by material color */ |
| 402 |
|
|
scalescolor(sctmp, 1.0-nd.trans); |
| 403 |
|
|
multambient(sctmp, r, nd.pnorm); |
| 404 |
|
|
saddscolor(r->rcol, sctmp); /* add to returned color */ |
| 405 |
greg |
1.5 |
} |
| 406 |
greg |
2.37 |
if (nd.trans > FTINY) { /* from other side */ |
| 407 |
greg |
2.14 |
vtmp[0] = -nd.pnorm[0]; |
| 408 |
|
|
vtmp[1] = -nd.pnorm[1]; |
| 409 |
|
|
vtmp[2] = -nd.pnorm[2]; |
| 410 |
greg |
2.40 |
copyscolor(sctmp, nd.mcolor); |
| 411 |
|
|
scalescolor(sctmp, nd.trans); |
| 412 |
|
|
multambient(sctmp, r, vtmp); |
| 413 |
|
|
saddscolor(r->rcol, sctmp); |
| 414 |
greg |
1.1 |
} |
| 415 |
|
|
/* add direct component */ |
| 416 |
|
|
direct(r, dirbrdf, &nd); |
| 417 |
greg |
2.10 |
|
| 418 |
|
|
return(1); |
| 419 |
greg |
1.10 |
} |
| 420 |
|
|
|
| 421 |
|
|
|
| 422 |
schorsch |
2.21 |
static int |
| 423 |
|
|
setbrdfunc( /* set up brdf function and variables */ |
| 424 |
greg |
2.28 |
BRDFDAT *np |
| 425 |
schorsch |
2.21 |
) |
| 426 |
greg |
1.10 |
{ |
| 427 |
|
|
FVECT vec; |
| 428 |
greg |
2.40 |
COLOR ctmp; |
| 429 |
greg |
1.10 |
|
| 430 |
|
|
if (setfunc(np->mp, np->pr) == 0) |
| 431 |
|
|
return(0); /* it's OK, setfunc says we're done */ |
| 432 |
|
|
/* else (re)assign special variables */ |
| 433 |
|
|
multv3(vec, np->pnorm, funcxf.xfm); |
| 434 |
greg |
2.37 |
varset("NxP`", '=', vec[0]/funcxf.sca); |
| 435 |
|
|
varset("NyP`", '=', vec[1]/funcxf.sca); |
| 436 |
|
|
varset("NzP`", '=', vec[2]/funcxf.sca); |
| 437 |
|
|
varset("RdotP`", '=', np->pdot <= -1.0 ? -1.0 : |
| 438 |
greg |
1.11 |
np->pdot >= 1.0 ? 1.0 : np->pdot); |
| 439 |
greg |
2.40 |
scolor_color(ctmp, np->mcolor); /* should use scolor_rgb()? */ |
| 440 |
|
|
varset("CrP", '=', colval(ctmp,RED)); |
| 441 |
|
|
varset("CgP", '=', colval(ctmp,GRN)); |
| 442 |
|
|
varset("CbP", '=', colval(ctmp,BLU)); |
| 443 |
greg |
1.10 |
return(1); |
| 444 |
greg |
1.1 |
} |
