| 1 |
greg |
2.1 |
#ifndef lint |
| 2 |
greg |
2.7 |
static const char RCSid[] = "$Id: checkBSDF.c,v 2.6 2022/01/26 17:30:07 greg Exp $"; |
| 3 |
greg |
2.1 |
#endif |
| 4 |
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/* |
| 5 |
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* checkBSDF.c |
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* |
| 7 |
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* Load BSDF XML file and check Helmholtz reciprocity |
| 8 |
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*/ |
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| 10 |
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#define _USE_MATH_DEFINES |
| 11 |
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#include <math.h> |
| 12 |
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#include "rtio.h" |
| 13 |
greg |
2.2 |
#include "random.h" |
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greg |
2.1 |
#include "bsdf.h" |
| 15 |
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#include "bsdf_m.h" |
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#include "bsdf_t.h" |
| 17 |
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#define F_IN_COLOR 0x1 |
| 19 |
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#define F_ISOTROPIC 0x2 |
| 20 |
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#define F_MATRIX 0x4 |
| 21 |
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#define F_TTREE 0x8 |
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greg |
2.2 |
typedef struct { |
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double vmin, vmax; /* extrema */ |
| 25 |
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double vsum; /* straight sum */ |
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long nvals; /* number of values */ |
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} SimpleStats; |
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const SimpleStats SSinit = {FHUGE, -FHUGE, .0, 0}; |
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/* relative difference formula */ |
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greg |
2.6 |
#define rdiff(a,b) ((a)>(b) ? ((a)-(b))/((a)+FTINY) : ((b)-(a))/((b)+FTINY)) |
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greg |
2.2 |
|
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greg |
2.1 |
/* Figure out BSDF type (and optionally determine if in color) */ |
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const char * |
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getBSDFtype(const SDData *bsdf, int *flags) |
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{ |
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const SDSpectralDF *df = bsdf->tb; |
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if (flags) *flags = 0; |
| 41 |
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if (!df) df = bsdf->tf; |
| 42 |
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if (!df) df = bsdf->rf; |
| 43 |
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if (!df) df = bsdf->rb; |
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if (!df) return "Pure_Lambertian"; |
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if (df->comp[0].func == &SDhandleMtx) { |
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const SDMat *m = (const SDMat *)df->comp[0].dist; |
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if (flags) { |
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*flags |= F_MATRIX; |
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*flags |= F_IN_COLOR*(m->chroma != NULL); |
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} |
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switch (m->ninc) { |
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case 145: |
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return "Klems_Full"; |
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case 73: |
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return "Klems_Half"; |
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case 41: |
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return "Klems_Quarter"; |
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} |
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return "Unknown_Matrix"; |
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} |
| 61 |
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if (df->comp[0].func == &SDhandleTre) { |
| 62 |
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const SDTre *t = (const SDTre *)df->comp[0].dist; |
| 63 |
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if (flags) { |
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*flags |= F_TTREE; |
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*flags |= F_IN_COLOR*(t->stc[1] != NULL); |
| 66 |
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} |
| 67 |
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switch (t->stc[0]->ndim) { |
| 68 |
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case 4: |
| 69 |
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return "Anisotropic_Tensor_Tree"; |
| 70 |
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case 3: |
| 71 |
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if (flags) *flags |= F_ISOTROPIC; |
| 72 |
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return "Isotropic_Tensor_Tree"; |
| 73 |
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} |
| 74 |
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return "Unknown_Tensor_Tree"; |
| 75 |
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} |
| 76 |
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return "Unknown"; |
| 77 |
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} |
| 78 |
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| 79 |
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/* Report details related to one hemisphere distribution */ |
| 80 |
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void |
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detailComponent(const char *nm, const SDValue *lamb, const SDSpectralDF *df) |
| 82 |
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{ |
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greg |
2.7 |
fputs(nm, stdout); |
| 84 |
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if (lamb->spec.flags) |
| 85 |
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printf("\t%4.1f %4.1f %4.1f\t\t", |
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greg |
2.2 |
100.*lamb->cieY*lamb->spec.cx/lamb->spec.cy, |
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greg |
2.1 |
100.*lamb->cieY, |
| 88 |
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100.*lamb->cieY*(1.f - lamb->spec.cx - lamb->spec.cy)/lamb->spec.cy); |
| 89 |
greg |
2.7 |
else |
| 90 |
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fputs("\t 0 0 0\t\t", stdout); |
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greg |
2.1 |
if (df) |
| 92 |
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printf("%5.1f%%\t\t%.2f deg\n", 100.*df->maxHemi, |
| 93 |
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sqrt(df->minProjSA/M_PI)*(360./M_PI)); |
| 94 |
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else |
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greg |
2.7 |
puts(" 0%\t\t180 deg"); |
| 96 |
greg |
2.1 |
} |
| 97 |
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greg |
2.2 |
/* Add a value to stats */ |
| 99 |
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void |
| 100 |
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addStat(SimpleStats *ssp, double v) |
| 101 |
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{ |
| 102 |
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if (v < ssp->vmin) ssp->vmin = v; |
| 103 |
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if (v > ssp->vmax) ssp->vmax = v; |
| 104 |
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ssp->vsum += v; |
| 105 |
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ssp->nvals++; |
| 106 |
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} |
| 107 |
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| 108 |
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/* Sample a BSDF hemisphere with callback (quadtree recursion) */ |
| 109 |
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int |
| 110 |
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qtSampBSDF(double xleft, double ytop, double siz, |
| 111 |
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const SDData *bsdf, const int side, const RREAL *v0, |
| 112 |
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int (*cf)(const SDData *b, const FVECT v1, const RREAL *v0, void *p), |
| 113 |
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void *cdata) |
| 114 |
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{ |
| 115 |
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if (siz < 0.124) { /* make sure we subdivide, first */ |
| 116 |
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FVECT vsmp; |
| 117 |
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double sa; |
| 118 |
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square2disk(vsmp, xleft + frandom()*siz, ytop + frandom()*siz); |
| 119 |
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vsmp[2] = 1. - vsmp[0]*vsmp[0] - vsmp[1]*vsmp[1]; |
| 120 |
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if (vsmp[2] <= 0) return 0; |
| 121 |
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vsmp[2] = side * sqrt(vsmp[2]); |
| 122 |
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if (SDreportError( SDsizeBSDF(&sa, vsmp, v0, SDqueryMin, bsdf), stderr)) |
| 123 |
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return 0; |
| 124 |
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if (sa >= M_PI*siz*siz - FTINY) /* no further division needed */ |
| 125 |
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return (*cf)(bsdf, vsmp, v0, cdata); |
| 126 |
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} |
| 127 |
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siz *= .5; /* 4-branch recursion */ |
| 128 |
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return( qtSampBSDF(xleft, ytop, siz, bsdf, side, v0, cf, cdata) && |
| 129 |
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qtSampBSDF(xleft+siz, ytop, siz, bsdf, side, v0, cf, cdata) && |
| 130 |
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qtSampBSDF(xleft, ytop+siz, siz, bsdf, side, v0, cf, cdata) && |
| 131 |
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qtSampBSDF(xleft+siz, ytop+siz, siz, bsdf, side, v0, cf, cdata) ); |
| 132 |
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} |
| 133 |
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| 134 |
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#define sampBSDFhemi(b,s,v0,cf,cd) qtSampBSDF(0,0,1,b,s,v0,cf,cd) |
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| 136 |
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/* Call-back to compute reciprocity difference */ |
| 137 |
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int |
| 138 |
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diffRecip(const SDData *bsdf, const FVECT v1, const RREAL *v0, void *p) |
| 139 |
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{ |
| 140 |
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SDValue sdv; |
| 141 |
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double otherY; |
| 142 |
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| 143 |
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if (SDreportError( SDevalBSDF(&sdv, v0, v1, bsdf), stderr)) |
| 144 |
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return 0; |
| 145 |
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otherY = sdv.cieY; |
| 146 |
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if (SDreportError( SDevalBSDF(&sdv, v1, v0, bsdf), stderr)) |
| 147 |
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return 0; |
| 148 |
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| 149 |
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addStat((SimpleStats *)p, rdiff(sdv.cieY, otherY)); |
| 150 |
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return 1; |
| 151 |
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} |
| 152 |
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| 153 |
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/* Call-back to compute reciprocity over reflected hemisphere */ |
| 154 |
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int |
| 155 |
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reflHemi(const SDData *bsdf, const FVECT v1, const RREAL *v0, void *p) |
| 156 |
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{ |
| 157 |
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return sampBSDFhemi(bsdf, 1 - 2*(v1[2]<0), v1, &diffRecip, p); |
| 158 |
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} |
| 159 |
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| 160 |
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/* Call-back to compute reciprocity over transmitted hemisphere */ |
| 161 |
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int |
| 162 |
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transHemi(const SDData *bsdf, const FVECT v1, const RREAL *v0, void *p) |
| 163 |
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{ |
| 164 |
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return sampBSDFhemi(bsdf, 1 - 2*(v1[2]>0), v1, &diffRecip, p); |
| 165 |
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} |
| 166 |
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greg |
2.1 |
/* Report reciprocity errors for the given directions */ |
| 168 |
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void |
| 169 |
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checkReciprocity(const char *nm, const int side1, const int side2, |
| 170 |
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const SDData *bsdf, const int fl) |
| 171 |
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{ |
| 172 |
greg |
2.2 |
SimpleStats myStats = SSinit; |
| 173 |
greg |
2.1 |
const SDSpectralDF *df = bsdf->tf; |
| 174 |
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| 175 |
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if (side1 == side2) { |
| 176 |
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df = (side1 > 0) ? bsdf->rf : bsdf->rb; |
| 177 |
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if (!df) goto nothing2do; |
| 178 |
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} else if (!bsdf->tf | !bsdf->tb) |
| 179 |
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goto nothing2do; |
| 180 |
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| 181 |
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if (fl & F_MATRIX) { /* special case for matrix BSDF */ |
| 182 |
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const SDMat *m = (const SDMat *)df->comp[0].dist; |
| 183 |
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int i = m->ninc; |
| 184 |
greg |
2.3 |
double diffuseY; |
| 185 |
greg |
2.1 |
FVECT vin, vout; |
| 186 |
greg |
2.2 |
double fwdY; |
| 187 |
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SDValue rev; |
| 188 |
greg |
2.3 |
if (side1 == side2) |
| 189 |
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diffuseY = (side1 > 0) ? bsdf->rLambFront.cieY : bsdf->rLambBack.cieY; |
| 190 |
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else |
| 191 |
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diffuseY = (side1 > 0) ? bsdf->tLambFront.cieY : bsdf->tLambBack.cieY; |
| 192 |
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diffuseY /= M_PI; |
| 193 |
greg |
2.1 |
while (i--) { |
| 194 |
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int o = m->nout; |
| 195 |
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if (!mBSDF_incvec(vin, m, i+.5)) |
| 196 |
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continue; |
| 197 |
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while (o--) { |
| 198 |
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if (!mBSDF_outvec(vout, m, o+.5)) |
| 199 |
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continue; |
| 200 |
greg |
2.3 |
fwdY = mBSDF_value(m, o, i) + diffuseY; |
| 201 |
greg |
2.2 |
if (fwdY <= 1e-4) |
| 202 |
greg |
2.1 |
continue; |
| 203 |
greg |
2.2 |
if (SDreportError( SDevalBSDF(&rev, vout, vin, bsdf), stderr)) |
| 204 |
greg |
2.1 |
return; |
| 205 |
greg |
2.2 |
if (rev.cieY > 1e-4) |
| 206 |
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addStat(&myStats, rdiff(fwdY, rev.cieY)); |
| 207 |
greg |
2.1 |
} |
| 208 |
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} |
| 209 |
greg |
2.3 |
} else if (fl & F_ISOTROPIC) { /* isotropic case */ |
| 210 |
greg |
2.2 |
const double stepSize = sqrt(df->minProjSA/M_PI); |
| 211 |
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FVECT vin; |
| 212 |
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vin[1] = 0; |
| 213 |
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for (vin[0] = 0.5*stepSize; vin[0] < 1; vin[0] += stepSize) { |
| 214 |
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vin[2] = side1*sqrt(1. - vin[0]*vin[0]); |
| 215 |
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if (!sampBSDFhemi(bsdf, side2, vin, &diffRecip, &myStats)) |
| 216 |
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return; |
| 217 |
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} |
| 218 |
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} else if (!sampBSDFhemi(bsdf, side1, NULL, |
| 219 |
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(side1==side2) ? &reflHemi : &transHemi, &myStats)) |
| 220 |
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return; |
| 221 |
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if (myStats.nvals) { |
| 222 |
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printf("%s\t%5.1f\t%5.1f\t%5.1f\n", nm, |
| 223 |
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100.*myStats.vmin, |
| 224 |
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100.*myStats.vsum/(double)myStats.nvals, |
| 225 |
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100.*myStats.vmax); |
| 226 |
greg |
2.1 |
return; |
| 227 |
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} |
| 228 |
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nothing2do: |
| 229 |
greg |
2.7 |
printf("%s\t 0\t 0\t 0\n", nm); |
| 230 |
greg |
2.1 |
} |
| 231 |
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| 232 |
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/* Report on the given BSDF XML file */ |
| 233 |
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int |
| 234 |
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checkXML(char *fname) |
| 235 |
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{ |
| 236 |
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int flags; |
| 237 |
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SDData myBSDF; |
| 238 |
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char *pth; |
| 239 |
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| 240 |
greg |
2.2 |
puts("====================================================="); |
| 241 |
greg |
2.1 |
printf("File: '%s'\n", fname); |
| 242 |
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SDclearBSDF(&myBSDF, fname); |
| 243 |
greg |
2.5 |
pth = getpath(fname, getrlibpath(), 0); |
| 244 |
greg |
2.1 |
if (!pth) { |
| 245 |
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fprintf(stderr, "Cannot find file '%s'\n", fname); |
| 246 |
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return 0; |
| 247 |
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} |
| 248 |
greg |
2.2 |
if (SDreportError( SDloadFile(&myBSDF, pth), stderr)) |
| 249 |
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return 0; |
| 250 |
greg |
2.1 |
printf("Manufacturer: '%s'\n", myBSDF.makr); |
| 251 |
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printf("BSDF Name: '%s'\n", myBSDF.matn); |
| 252 |
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printf("Dimensions (W x H x Thickness): %g x %g x %g cm\n", 100.*myBSDF.dim[0], |
| 253 |
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100.*myBSDF.dim[1], 100.*myBSDF.dim[2]); |
| 254 |
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printf("Type: %s\n", getBSDFtype(&myBSDF, &flags)); |
| 255 |
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printf("Color: %d\n", (flags & F_IN_COLOR) != 0); |
| 256 |
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printf("Has Geometry: %d\n", (myBSDF.mgf != NULL)); |
| 257 |
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puts("Component\tLambertian XYZ %\tMax. Dir\tMin. Angle"); |
| 258 |
greg |
2.4 |
detailComponent("Interior Refl", &myBSDF.rLambFront, myBSDF.rf); |
| 259 |
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detailComponent("Exterior Refl", &myBSDF.rLambBack, myBSDF.rb); |
| 260 |
greg |
2.1 |
detailComponent("Int->Ext Trans", &myBSDF.tLambFront, myBSDF.tf); |
| 261 |
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detailComponent("Ext->Int Trans", &myBSDF.tLambBack, myBSDF.tb); |
| 262 |
greg |
2.2 |
puts("Component\tReciprocity Error (min avg max %)"); |
| 263 |
greg |
2.4 |
checkReciprocity("Interior Refl", 1, 1, &myBSDF, flags); |
| 264 |
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checkReciprocity("Exterior Refl", -1, -1, &myBSDF, flags); |
| 265 |
greg |
2.1 |
checkReciprocity("Transmission", -1, 1, &myBSDF, flags); |
| 266 |
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SDfreeBSDF(&myBSDF); |
| 267 |
|
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return 1; |
| 268 |
|
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} |
| 269 |
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| 270 |
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int |
| 271 |
|
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main(int argc, char *argv[]) |
| 272 |
|
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{ |
| 273 |
|
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int i; |
| 274 |
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| 275 |
|
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if (argc < 2) { |
| 276 |
|
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fprintf(stderr, "Usage: %s bsdf.xml ..\n", argv[0]); |
| 277 |
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return 1; |
| 278 |
|
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} |
| 279 |
greg |
2.2 |
for (i = 1; i < argc; i++) |
| 280 |
greg |
2.1 |
if (!checkXML(argv[i])) |
| 281 |
|
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return 1; |
| 282 |
|
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return 0; |
| 283 |
|
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} |
