/* Build our triangle mesh from recorded RBFs */
void
build_mesh(void)
{
double best2 = M_PI*M_PI;
RBFNODE *shrt_edj[2];
RBFNODE *rbf0, *rbf1;
/* check if isotropic */
if (single_plane_incident) {
for (rbf0 = dsf_list; rbf0 != NULL; rbf0 = rbf0->next)
if (rbf0->next != NULL)
create_migration(rbf0, rbf0->next);
await_children(nchild);
return;
}
shrt_edj[0] = shrt_edj[1] = NULL; /* start w/ shortest edge */
for (rbf0 = dsf_list; rbf0 != NULL; rbf0 = rbf0->next)
for (rbf1 = rbf0->next; rbf1 != NULL; rbf1 = rbf1->next) {
double dist2 = 2. - 2.*DOT(rbf0->invec,rbf1->invec);
if (dist2 < best2) {
shrt_edj[0] = rbf0;
shrt_edj[1] = rbf1;
best2 = dist2;
}
}
if (shrt_edj[0] == NULL) {
fprintf(stderr, "%s: Cannot find shortest edge\n", progname);
exit(1);
}
/* build mesh from this edge */
if (shrt_edj[0]->ord < shrt_edj[1]->ord)
mesh_from_edge(create_migration(shrt_edj[0], shrt_edj[1]));
else
mesh_from_edge(create_migration(shrt_edj[1], shrt_edj[0]));
/* compute minimum BSDF */
comp_bsdf_min();
/* complete migrations */
await_children(nchild);
}
/* Count up filled nodes and build RBF representation from current grid */
RBFNODE *
make_rbfrep(void)
{
int niter = 16;
double lastVar, thisVar = 100.;
int nn;
RBFNODE *newnode;
RBFVAL *itera;
int i, j;
/* compute RBF radii */
compute_radii();
/* coagulate lobes */
cull_values();
nn = 0; /* count selected bins */
for (i = 0; i < GRIDRES; i++)
for (j = 0; j < GRIDRES; j++)
nn += dsf_grid[i][j].nval;
/* compute minimum BSDF */
comp_bsdf_min();
/* allocate RBF array */
newnode = (RBFNODE *)malloc(sizeof(RBFNODE) + sizeof(RBFVAL)*(nn-1));
if (newnode == NULL)
goto memerr;
newnode->ord = -1;
newnode->next = NULL;
newnode->ejl = NULL;
newnode->invec[2] = sin((M_PI/180.)*theta_in_deg);
newnode->invec[0] = cos((M_PI/180.)*phi_in_deg)*newnode->invec[2];
newnode->invec[1] = sin((M_PI/180.)*phi_in_deg)*newnode->invec[2];
newnode->invec[2] = input_orient*sqrt(1. - newnode->invec[2]*newnode->invec[2]);
newnode->vtotal = 0;
newnode->nrbf = nn;
nn = 0; /* fill RBF array */
for (i = 0; i < GRIDRES; i++)
for (j = 0; j < GRIDRES; j++)
if (dsf_grid[i][j].nval) {
newnode->rbfa[nn].peak = dsf_grid[i][j].vsum;
newnode->rbfa[nn].crad = RSCA*dsf_grid[i][j].crad + .5;
newnode->rbfa[nn].gx = i;
newnode->rbfa[nn].gy = j;
++nn;
}
/* iterate to improve interpolation accuracy */
itera = (RBFVAL *)malloc(sizeof(RBFVAL)*newnode->nrbf);
if (itera == NULL)
goto memerr;
memcpy(itera, newnode->rbfa, sizeof(RBFVAL)*newnode->nrbf);
do {
double dsum = 0, dsum2 = 0;
nn = 0;
for (i = 0; i < GRIDRES; i++)
for (j = 0; j < GRIDRES; j++)
if (dsf_grid[i][j].nval) {
FVECT odir;
double corr;
ovec_from_pos(odir, i, j);
itera[nn++].peak *= corr =
dsf_grid[i][j].vsum /
eval_rbfrep(newnode, odir);
dsum += 1. - corr;
dsum2 += (1.-corr)*(1.-corr);
}
memcpy(newnode->rbfa, itera, sizeof(RBFVAL)*newnode->nrbf);
lastVar = thisVar;
thisVar = dsum2/(double)nn;
#ifdef DEBUG
fprintf(stderr, "Avg., RMS error: %.1f%% %.1f%%\n",
100.*dsum/(double)nn,
100.*sqrt(thisVar));
#endif
} while (--niter > 0 && lastVar-thisVar > 0.02*lastVar);
free(itera);
nn = 0; /* compute sum for normalization */
while (nn < newnode->nrbf)
newnode->vtotal += rbf_volume(&newnode->rbfa[nn++]);
#ifdef DEBUG
fprintf(stderr, "Integrated DSF at (%.1f,%.1f) deg. is %.2f\n",
get_theta180(newnode->invec), get_phi360(newnode->invec),
newnode->vtotal);
#endif
insert_dsf(newnode);
return(newnode);
memerr:
fprintf(stderr, "%s: Out of memory in make_rbfrep()\n", progname);
exit(1);
}
