--- ray/src/cv/bsdfrep.c 2012/10/23 05:10:42 2.4 +++ ray/src/cv/bsdfrep.c 2013/03/24 17:22:23 2.13 @@ -1,5 +1,5 @@ #ifndef lint -static const char RCSid[] = "$Id: bsdfrep.c,v 2.4 2012/10/23 05:10:42 greg Exp $"; +static const char RCSid[] = "$Id: bsdfrep.c,v 2.13 2013/03/24 17:22:23 greg Exp $"; #endif /* * Support BSDF representation as radial basis functions. @@ -14,6 +14,9 @@ static const char RCSid[] = "$Id: bsdfrep.c,v 2.4 2012 #include "rtio.h" #include "resolu.h" #include "bsdfrep.h" + /* active grid resolution */ +int grid_res = GRIDRES; + /* coverage/symmetry using INP_QUAD? flags */ int inp_coverage = 0; /* all incident angles in-plane so far? */ @@ -23,6 +26,12 @@ int single_plane_incident = -1; int input_orient = 0; int output_orient = 0; + /* BSDF histogram */ +int bsdf_hist[HISTLEN]; + + /* BSDF value for boundary regions */ +double bsdf_min = 0; + /* processed incident DSF measurements */ RBFNODE *dsf_list = NULL; @@ -53,6 +62,8 @@ new_input_direction(double new_theta, double new_phi) new_theta = -new_theta; new_phi += 180.; } + if ((theta_in_deg = new_theta) < 1.0) + return(1); /* don't rely on phi near normal */ while (new_phi < 0) new_phi += 360.; while (new_phi >= 360.) @@ -61,7 +72,6 @@ new_input_direction(double new_theta, double new_phi) single_plane_incident = (round(new_phi) == round(phi_in_deg)); else if (single_plane_incident < 0) single_plane_incident = 1; - theta_in_deg = new_theta; /* assume it's OK */ phi_in_deg = new_phi; if ((1. < new_phi) & (new_phi < 89.)) inp_coverage |= INP_QUAD1; @@ -78,7 +88,7 @@ new_input_direction(double new_theta, double new_phi) int use_symmetry(FVECT vec) { - double phi = get_phi360(vec); + const double phi = get_phi360(vec); switch (inp_coverage) { case INP_QUAD1|INP_QUAD2|INP_QUAD3|INP_QUAD4: @@ -168,12 +178,33 @@ rev_rbf_symmetry(RBFNODE *rbf, int sym) rev_symmetry(rbf->invec, sym); if (sym & MIRROR_X) for (n = rbf->nrbf; n-- > 0; ) - rbf->rbfa[n].gx = GRIDRES-1 - rbf->rbfa[n].gx; + rbf->rbfa[n].gx = grid_res-1 - rbf->rbfa[n].gx; if (sym & MIRROR_Y) for (n = rbf->nrbf; n-- > 0; ) - rbf->rbfa[n].gy = GRIDRES-1 - rbf->rbfa[n].gy; + rbf->rbfa[n].gy = grid_res-1 - rbf->rbfa[n].gy; } +/* Rotate RBF to correspond to given incident vector */ +void +rotate_rbf(RBFNODE *rbf, const FVECT invec) +{ + static const FVECT vnorm = {.0, .0, 1.}; + const double phi = atan2(invec[1],invec[0]) - + atan2(rbf->invec[1],rbf->invec[0]); + FVECT outvec; + int pos[2]; + int n; + + for (n = ((-.01 > phi) | (phi > .01))*rbf->nrbf; n-- > 0; ) { + ovec_from_pos(outvec, rbf->rbfa[n].gx, rbf->rbfa[n].gy); + spinvector(outvec, outvec, vnorm, phi); + pos_from_vec(pos, outvec); + rbf->rbfa[n].gx = pos[0]; + rbf->rbfa[n].gy = pos[1]; + } + VCOPY(rbf->invec, invec); +} + /* Compute volume associated with Gaussian lobe */ double rbf_volume(const RBFVAL *rbfp) @@ -190,7 +221,7 @@ ovec_from_pos(FVECT vec, int xpos, int ypos) double uv[2]; double r2; - SDsquare2disk(uv, (1./GRIDRES)*(xpos+.5), (1./GRIDRES)*(ypos+.5)); + SDsquare2disk(uv, (xpos+.5)/grid_res, (ypos+.5)/grid_res); /* uniform hemispherical projection */ r2 = uv[0]*uv[0] + uv[1]*uv[1]; vec[0] = vec[1] = sqrt(2. - r2); @@ -208,22 +239,26 @@ pos_from_vec(int pos[2], const FVECT vec) SDdisk2square(sq, vec[0]*norm, vec[1]*norm); - pos[0] = (int)(sq[0]*GRIDRES); - pos[1] = (int)(sq[1]*GRIDRES); + pos[0] = (int)(sq[0]*grid_res); + pos[1] = (int)(sq[1]*grid_res); } /* Evaluate RBF for DSF at the given normalized outgoing direction */ double eval_rbfrep(const RBFNODE *rp, const FVECT outvec) { - double res = .0; + double minval = bsdf_min*output_orient*outvec[2]; + double res = 0; const RBFVAL *rbfp; FVECT odir; double sig2; int n; - - if (rp == NULL) - return(.0); + /* use minimum if no information avail. */ + if (rp == NULL) { + if (outvec[2] > 0 ^ output_orient > 0) + return(.0); + return(minval); + } rbfp = rp->rbfa; for (n = rp->nrbf; n--; rbfp++) { ovec_from_pos(odir, rbfp->gx, rbfp->gy); @@ -232,6 +267,8 @@ eval_rbfrep(const RBFNODE *rp, const FVECT outvec) if (sig2 > -19.) res += rbfp->peak * exp(sig2); } + if (res < minval) /* never return less than minval */ + return(minval); return(res); } @@ -351,6 +388,7 @@ clear_bsdf_rep(void) inp_coverage = 0; single_plane_incident = -1; input_orient = output_orient = 0; + grid_res = GRIDRES; } /* Write our BSDF mesh interpolant out to the given binary stream */ @@ -363,6 +401,8 @@ save_bsdf_rep(FILE *ofp) /* finish header */ fprintf(ofp, "SYMMETRY=%d\n", !single_plane_incident * inp_coverage); fprintf(ofp, "IO_SIDES= %d %d\n", input_orient, output_orient); + fprintf(ofp, "GRIDRES=%d\n", grid_res); + fprintf(ofp, "BSDFMIN=%g\n", bsdf_min); fputformat(BSDFREP_FMT, ofp); fputc('\n', ofp); /* write each DSF */ @@ -424,6 +464,14 @@ headline(char *s, void *p) sscanf(s+9, "%d %d", &input_orient, &output_orient); return(0); } + if (!strncmp(s, "GRIDRES=", 8)) { + sscanf(s+8, "%d", &grid_res); + return(0); + } + if (!strncmp(s, "BSDFMIN=", 8)) { + sscanf(s+8, "%lf", &bsdf_min); + return(0); + } if (formatval(fmt, s) && strcmp(fmt, BSDFREP_FMT)) return(-1); return(0); @@ -438,6 +486,8 @@ load_bsdf_rep(FILE *ifp) int i; clear_bsdf_rep(); + if (ifp == NULL) + return(0); if (getheader(ifp, headline, NULL) < 0 || single_plane_incident < 0 | !input_orient | !output_orient) { fprintf(stderr, "%s: missing/bad format for BSDF interpolant\n", @@ -452,13 +502,17 @@ load_bsdf_rep(FILE *ifp) rbfh.invec[0] = getflt(ifp); rbfh.invec[1] = getflt(ifp); rbfh.invec[2] = getflt(ifp); + if (normalize(rbfh.invec) == 0) { + fprintf(stderr, "%s: zero incident vector\n", progname); + return(0); + } rbfh.vtotal = getflt(ifp); rbfh.nrbf = getint(4, ifp); newrbf = (RBFNODE *)malloc(sizeof(RBFNODE) + sizeof(RBFVAL)*(rbfh.nrbf-1)); if (newrbf == NULL) goto memerr; - memcpy(newrbf, &rbfh, sizeof(RBFNODE)); + memcpy(newrbf, &rbfh, sizeof(RBFNODE)-sizeof(RBFVAL)); for (i = 0; i < rbfh.nrbf; i++) { newrbf->rbfa[i].peak = getflt(ifp); newrbf->rbfa[i].crad = getint(2, ifp) & 0xffff;