src/gen/mkillum2.c

#ifndef lint
static const char       RCSid[] = "$Id: mkillum2.c,v 2.29 2009/03/04 00:12:25 greg Exp $";
#endif
/*
 * Routines to do the actual calculation for mkillum
 */

#include <string.h>

#include  "mkillum.h"
#include  "face.h"
#include  "cone.h"
#include  "source.h"


COLORV *        distarr = NULL;         /* distribution array */
int             distsiz = 0;
COLORV *        direct_discount = NULL; /* amount to take off direct */

void
newdist(                        /* allocate & clear distribution array */
        int siz
)
{
        if (siz <= 0) {
                if (distsiz > 0)
                        free((void *)distarr);
                distarr = NULL;
                distsiz = 0;
                return;
        }
        if (distsiz < siz) {
                if (distsiz > 0)
                        free((void *)distarr);
                distarr = (COLORV *)malloc(sizeof(COLOR)*siz);
                if (distarr == NULL)
                        error(SYSTEM, "out of memory in newdist");
                distsiz = siz;
        }
        memset(distarr, '\0', sizeof(COLOR)*siz);
}


static void
new_discount()                  /* allocate space for direct contrib. record */
{
        if (distsiz <= 0)
                return;
        direct_discount = (COLORV *)calloc(distsiz, sizeof(COLOR));
        if (direct_discount == NULL)
                error(SYSTEM, "out of memory in new_discount");
}


static void
done_discount()                 /* clear off direct contrib. record */
{
        if (direct_discount == NULL)
                return;
        free((void *)direct_discount);
        direct_discount = NULL;
}


int
process_ray(                    /* process a ray result or report error */
        RAY *r,
        int rv
)
{
        COLORV  *colp;

        if (rv == 0)                    /* no result ready */
                return(0);
        if (rv < 0)
                error(USER, "ray tracing process died");
        if (r->rno >= distsiz)
                error(INTERNAL, "bad returned index in process_ray");
        multcolor(r->rcol, r->rcoef);   /* in case it's a source ray */
        colp = &distarr[r->rno * 3];
        addcolor(colp, r->rcol);
        if (r->rsrc >= 0 &&             /* remember source contrib. */
                        direct_discount != NULL) {
                colp = &direct_discount[r->rno * 3];
                addcolor(colp, r->rcol);
        }
        return(1);
}


void
raysamp(                        /* queue a ray sample */
        int  ndx,
        FVECT  org,
        FVECT  dir
)
{
        RAY     myRay;
        int     rv;

        if ((ndx < 0) | (ndx >= distsiz))
                error(INTERNAL, "bad index in raysamp");
        VCOPY(myRay.rorg, org);
        VCOPY(myRay.rdir, dir);
        myRay.rmax = .0;
        rayorigin(&myRay, PRIMARY, NULL, NULL);
        myRay.rno = ndx;
                                        /* queue ray, check result */
        process_ray(&myRay, ray_pqueue(&myRay));
}


void
srcsamps(                       /* sample sources from this surface position */
        struct illum_args *il,
        FVECT org,
        FVECT nrm,
        MAT4 ixfm
)
{
        int  nalt, nazi;
        SRCINDEX  si;
        RAY  sr;
        FVECT   v;
        double  d;
        int  i, j;
                                                /* get sampling density */
        if (il->sampdens <= 0) {
                nalt = nazi = 1;
        } else {
                i = PI * il->sampdens;
                nalt = sqrt(i/PI) + .5;
                nazi = PI*nalt + .5;
        }
        initsrcindex(&si);                      /* loop over (sub)sources */
        for ( ; ; ) {
                VCOPY(sr.rorg, org);            /* pick side to shoot from */
                if (il->sd != NULL) {
                        int  sn = si.sn;
                        if (si.sp+1 >= si.np) ++sn;
                        if (sn >= nsources) break;
                        if (source[sn].sflags & SDISTANT)
                                d = DOT(source[sn].sloc, nrm);
                        else {
                                VSUB(v, source[sn].sloc, org);
                                d = DOT(v, nrm);
                        }
                } else
                        d = 1.0;                /* only transmission */
                if (d < 0.0)
                        d = -1.0001*il->thick - 5.*FTINY;
                else
                        d = 5.*FTINY;
                for (i = 3; i--; )
                        sr.rorg[i] += d*nrm[i];
                samplendx++;                    /* increment sample counter */
                if (!srcray(&sr, NULL, &si))
                        break;                  /* end of sources */
                                                /* index direction */
                if (ixfm != NULL)
                        multv3(v, sr.rdir, ixfm);
                else
                        VCOPY(v, sr.rdir);
                if (il->sd != NULL) {
                        i = getBSDF_incndx(il->sd, v);
                        if (i < 0)
                                continue;       /* must not be important */
                        sr.rno = i;
                        d = 1.0/getBSDF_incohm(il->sd, i);
                } else {
                        if (v[2] >= -FTINY)
                                continue;       /* only sample transmission */
                        v[0] = -v[0]; v[1] = -v[1]; v[2] = -v[2];
                        sr.rno = flatindex(v, nalt, nazi);
                        d = nalt*nazi*(1./PI) * v[2];
                }
                d *= si.dom;                    /* solid angle correction */
                scalecolor(sr.rcoef, d);
                process_ray(&sr, ray_pqueue(&sr));
        }
}


void
rayclean()                      /* finish all pending rays */
{
        RAY     myRay;

        while (process_ray(&myRay, ray_presult(&myRay, 0)))
                ;
}


static void
mkaxes(                 /* compute u and v to go with n */
        FVECT  u,
        FVECT  v,
        FVECT  n
)
{
        register int  i;

        v[0] = v[1] = v[2] = 0.0;
        for (i = 0; i < 3; i++)
                if (n[i] < 0.6 && n[i] > -0.6)
                        break;
        v[i] = 1.0;
        fcross(u, v, n);
        normalize(u);
        fcross(v, n, u);
}


static void
rounddir(               /* compute uniform spherical direction */
        register FVECT  dv,
        double  alt,
        double  azi
)
{
        double  d1, d2;

        dv[2] = 1. - 2.*alt;
        d1 = sqrt(1. - dv[2]*dv[2]);
        d2 = 2.*PI * azi;
        dv[0] = d1*cos(d2);
        dv[1] = d1*sin(d2);
}


void
flatdir(                /* compute uniform hemispherical direction */
        FVECT  dv,
        double  alt,
        double  azi
)
{
        double  d1, d2;

        d1 = sqrt(alt);
        d2 = 2.*PI * azi;
        dv[0] = d1*cos(d2);
        dv[1] = d1*sin(d2);
        dv[2] = sqrt(1. - alt);
}

int
flatindex(              /* compute index for hemispherical direction */
        FVECT   dv,
        int     nalt,
        int     nazi
)
{
        double  d;
        int     i, j;
        
        d = 1.0 - dv[2]*dv[2];
        i = d*nalt;
        d = atan2(dv[1], dv[0]) * (0.5/PI);
        if (d < 0.0) d += 1.0;
        j = d*nazi + 0.5;
        if (j >= nazi) j = 0;
        return(i*nazi + j);
}


int
my_default(     /* default illum action */
        OBJREC  *ob,
        struct illum_args  *il,
        char  *nm
)
{
        sprintf(errmsg, "(%s): cannot make illum for %s \"%s\"",
                        nm, ofun[ob->otype].funame, ob->oname);
        error(WARNING, errmsg);
        printobj(il->altmat, ob);
        return(1);
}


int
my_face(                /* make an illum face */
        OBJREC  *ob,
        struct illum_args  *il,
        char  *nm
)
{
        int  dim[2];
        int  n, nalt, nazi, alti;
        double  sp[2], r1, r2;
        int  h;
        FVECT  dn, org, dir;
        FVECT  u, v;
        double  ur[2], vr[2];
        MAT4  xfm;
        int  nallow;
        FACE  *fa;
        int  i, j;
                                /* get/check arguments */
        fa = getface(ob);
        if (fa->area == 0.0) {
                freeface(ob);
                return(my_default(ob, il, nm));
        }
                                /* set up sampling */
        if (il->sd != NULL) {
                if (!getBSDF_xfm(xfm, fa->norm, il->udir)) {
                        objerror(ob, WARNING, "illegal up direction");
                        freeface(ob);
                        return(my_default(ob, il, nm));
                }
                n = il->sd->ninc;
        } else {
                if (il->sampdens <= 0) {
                        nalt = nazi = 1;        /* diffuse assumption */
                } else {
                        n = PI * il->sampdens;
                        nalt = sqrt(n/PI) + .5;
                        nazi = PI*nalt + .5;
                }
                n = nazi*nalt;
        }
        newdist(n);
                                /* take first edge >= sqrt(area) */
        for (j = fa->nv-1, i = 0; i < fa->nv; j = i++) {
                u[0] = VERTEX(fa,i)[0] - VERTEX(fa,j)[0];
                u[1] = VERTEX(fa,i)[1] - VERTEX(fa,j)[1];
                u[2] = VERTEX(fa,i)[2] - VERTEX(fa,j)[2];
                if ((r1 = DOT(u,u)) >= fa->area-FTINY)
                        break;
        }
        if (i < fa->nv) {       /* got one! -- let's align our axes */
                r2 = 1.0/sqrt(r1);
                u[0] *= r2; u[1] *= r2; u[2] *= r2;
                fcross(v, fa->norm, u);
        } else                  /* oh well, we'll just have to wing it */
                mkaxes(u, v, fa->norm);
                                /* now, find limits in (u,v) coordinates */
        ur[0] = vr[0] = FHUGE;
        ur[1] = vr[1] = -FHUGE;
        for (i = 0; i < fa->nv; i++) {
                r1 = DOT(VERTEX(fa,i),u);
                if (r1 < ur[0]) ur[0] = r1;
                if (r1 > ur[1]) ur[1] = r1;
                r2 = DOT(VERTEX(fa,i),v);
                if (r2 < vr[0]) vr[0] = r2;
                if (r2 > vr[1]) vr[1] = r2;
        }
        dim[0] = random();
                                /* sample polygon */
        nallow = 5*n*il->nsamps;
        for (dim[1] = 0; dim[1] < n; dim[1]++)
                for (i = 0; i < il->nsamps; i++) {
                                        /* randomize direction */
                    h = ilhash(dim, 2) + i;
                    if (il->sd != NULL) {
                        r_BSDF_incvec(dir, il->sd, dim[1], urand(h), xfm);
                    } else {
                        multisamp(sp, 2, urand(h));
                        alti = dim[1]/nazi;
                        r1 = (alti + sp[0])/nalt;
                        r2 = (dim[1] - alti*nazi + sp[1] - .5)/nazi;
                        flatdir(dn, r1, r2);
                        for (j = 0; j < 3; j++)
                            dir[j] = -dn[0]*u[j] - dn[1]*v[j] -
                                                dn[2]*fa->norm[j];
                    }
                                        /* randomize location */
                    do {
                        multisamp(sp, 2, urand(h+4862+nallow));
                        r1 = ur[0] + (ur[1]-ur[0]) * sp[0];
                        r2 = vr[0] + (vr[1]-vr[0]) * sp[1];
                        for (j = 0; j < 3; j++)
                            org[j] = r1*u[j] + r2*v[j]
                                        + fa->offset*fa->norm[j];
                    } while (!inface(org, fa) && nallow-- > 0);
                    if (nallow < 0) {
                        objerror(ob, WARNING, "bad aspect");
                        rayclean();
                        freeface(ob);
                        return(my_default(ob, il, nm));
                    }
                    if (il->sd != NULL && DOT(dir, fa->norm) < -FTINY)
                        r1 = -1.0001*il->thick - 5.*FTINY;
                    else
                        r1 = 5.*FTINY;
                    for (j = 0; j < 3; j++)
                        org[j] += r1*fa->norm[j];
                                        /* send sample */
                    raysamp(dim[1], org, dir);
                }
                                /* add in direct component? */
        if (!directvis && (il->flags & IL_LIGHT || il->sd != NULL)) {
                MAT4    ixfm;
                if (il->sd == NULL) {
                        for (i = 3; i--; ) {
                                ixfm[i][0] = u[i];
                                ixfm[i][1] = v[i];
                                ixfm[i][2] = fa->norm[i];
                                ixfm[i][3] = 0.;
                        }
                        ixfm[3][0] = ixfm[3][1] = ixfm[3][2] = 0.;
                        ixfm[3][3] = 1.;
                } else {
                        if (!invmat4(ixfm, xfm))
                                objerror(ob, INTERNAL,
                                        "cannot invert BSDF transform");
                        if (!(il->flags & IL_LIGHT))
                                new_discount();
                }
                dim[0] = random();
                nallow = 10*il->nsamps;
                for (i = 0; i < il->nsamps; i++) {
                                        /* randomize location */
                    h = dim[0] + samplendx++;
                    do {
                        multisamp(sp, 2, urand(h+nallow));
                        r1 = ur[0] + (ur[1]-ur[0]) * sp[0];
                        r2 = vr[0] + (vr[1]-vr[0]) * sp[1];
                        for (j = 0; j < 3; j++)
                            org[j] = r1*u[j] + r2*v[j]
                                        + fa->offset*fa->norm[j];
                    } while (!inface(org, fa) && nallow-- > 0);
                    if (nallow < 0) {
                        objerror(ob, WARNING, "bad aspect");
                        rayclean();
                        freeface(ob);
                        return(my_default(ob, il, nm));
                    }
                                        /* sample source rays */
                    srcsamps(il, org, fa->norm, ixfm);
                }
        }
                                /* wait for all rays to finish */
        rayclean();
        if (il->sd != NULL) {   /* run distribution through BSDF */
                nalt = sqrt(il->sd->nout/PI) + .5;
                nazi = PI*nalt + .5;
                redistribute(il->sd, nalt, nazi, u, v, fa->norm, xfm);
                done_discount();
                if (!il->sampdens)
                        il->sampdens = nalt*nazi/PI + .999;
        }
                                /* write out the face and its distribution */
        if (average(il, distarr, n)) {
                if (il->sampdens > 0)
                        flatout(il, distarr, nalt, nazi, u, v, fa->norm);
                illumout(il, ob);
        } else
                printobj(il->altmat, ob);
                                /* clean up */
        freeface(ob);
        return(0);
}


int
my_sphere(      /* make an illum sphere */
        register OBJREC  *ob,
        struct illum_args  *il,
        char  *nm
)
{
        int  dim[3];
        int  n, nalt, nazi;
        double  sp[4], r1, r2, r3;
        FVECT  org, dir;
        FVECT  u, v;
        register int  i, j;
                                /* check arguments */
        if (ob->oargs.nfargs != 4)
                objerror(ob, USER, "bad # of arguments");
                                /* set up sampling */
        if (il->sampdens <= 0)
                nalt = nazi = 1;
        else {
                n = 4.*PI * il->sampdens;
                nalt = sqrt(2./PI*n) + .5;
                nazi = PI/2.*nalt + .5;
        }
        if (il->sd != NULL)
                objerror(ob, WARNING, "BSDF ignored");
        n = nalt*nazi;
        newdist(n);
        dim[0] = random();
                                /* sample sphere */
        for (dim[1] = 0; dim[1] < nalt; dim[1]++)
            for (dim[2] = 0; dim[2] < nazi; dim[2]++)
                for (i = 0; i < il->nsamps; i++) {
                                        /* next sample point */
                    multisamp(sp, 4, urand(ilhash(dim,3)+i));
                                        /* random direction */
                    r1 = (dim[1] + sp[0])/nalt;
                    r2 = (dim[2] + sp[1] - .5)/nazi;
                    rounddir(dir, r1, r2);
                                        /* random location */
                    mkaxes(u, v, dir);          /* yuck! */
                    r3 = sqrt(sp[2]);
                    r2 = 2.*PI*sp[3];
                    r1 = r3*ob->oargs.farg[3]*cos(r2);
                    r2 = r3*ob->oargs.farg[3]*sin(r2);
                    r3 = ob->oargs.farg[3]*sqrt(1.01-r3*r3);
                    for (j = 0; j < 3; j++) {
                        org[j] = ob->oargs.farg[j] + r1*u[j] + r2*v[j] +
                                        r3*dir[j];
                        dir[j] = -dir[j];
                    }
                                        /* send sample */
                    raysamp(dim[1]*nazi+dim[2], org, dir);
                }
                                /* wait for all rays to finish */
        rayclean();
                                /* write out the sphere and its distribution */
        if (average(il, distarr, n)) {
                if (il->sampdens > 0)
                        roundout(il, distarr, nalt, nazi);
                else
                        objerror(ob, WARNING, "diffuse distribution");
                illumout(il, ob);
        } else
                printobj(il->altmat, ob);
                                /* clean up */
        return(1);
}


int
my_ring(                /* make an illum ring */
        OBJREC  *ob,
        struct illum_args  *il,
        char  *nm
)
{
        int  dim[2];
        int  n, nalt, nazi, alti;
        double  sp[2], r1, r2, r3;
        int  h;
        FVECT  dn, org, dir;
        FVECT  u, v;
        MAT4  xfm;
        CONE  *co;
        int  i, j;
                                /* get/check arguments */
        co = getcone(ob, 0);
                                /* set up sampling */
        if (il->sd != NULL) {
                if (!getBSDF_xfm(xfm, co->ad, il->udir)) {
                        objerror(ob, WARNING, "illegal up direction");
                        freecone(ob);
                        return(my_default(ob, il, nm));
                }
                n = il->sd->ninc;
        } else {
                if (il->sampdens <= 0) {
                        nalt = nazi = 1;        /* diffuse assumption */
                } else {
                        n = PI * il->sampdens;
                        nalt = sqrt(n/PI) + .5;
                        nazi = PI*nalt + .5;
                }
                n = nazi*nalt;
        }
        newdist(n);
        mkaxes(u, v, co->ad);
        dim[0] = random();
                                /* sample disk */
        for (dim[1] = 0; dim[1] < n; dim[1]++)
                for (i = 0; i < il->nsamps; i++) {
                                        /* next sample point */
                    h = ilhash(dim,2) + i;
                                        /* randomize direction */
                    if (il->sd != NULL) {
                        r_BSDF_incvec(dir, il->sd, dim[1], urand(h), xfm);
                    } else {
                        multisamp(sp, 2, urand(h));
                        alti = dim[1]/nazi;
                        r1 = (alti + sp[0])/nalt;
                        r2 = (dim[1] - alti*nazi + sp[1] - .5)/nazi;
                        flatdir(dn, r1, r2);
                        for (j = 0; j < 3; j++)
                                dir[j] = -dn[0]*u[j] - dn[1]*v[j] - dn[2]*co->ad[j];
                    }
                                        /* randomize location */
                    multisamp(sp, 2, urand(h+8371));
                    r3 = sqrt(CO_R0(co)*CO_R0(co) +
                            sp[0]*(CO_R1(co)*CO_R1(co) - CO_R0(co)*CO_R0(co)));
                    r2 = 2.*PI*sp[1];
                    r1 = r3*cos(r2);
                    r2 = r3*sin(r2);
                    if (il->sd != NULL && DOT(dir, co->ad) < -FTINY)
                        r3 = -1.0001*il->thick - 5.*FTINY;
                    else
                        r3 = 5.*FTINY;
                    for (j = 0; j < 3; j++)
                        org[j] = CO_P0(co)[j] + r1*u[j] + r2*v[j] +
                                                r3*co->ad[j];
                                        /* send sample */
                    raysamp(dim[1], org, dir);
                }
                                /* add in direct component? */
        if (!directvis && (il->flags & IL_LIGHT || il->sd != NULL)) {
                MAT4    ixfm;
                if (il->sd == NULL) {
                        for (i = 3; i--; ) {
                                ixfm[i][0] = u[i];
                                ixfm[i][1] = v[i];
                                ixfm[i][2] = co->ad[i];
                                ixfm[i][3] = 0.;
                        }
                        ixfm[3][0] = ixfm[3][1] = ixfm[3][2] = 0.;
                        ixfm[3][3] = 1.;
                } else {
                        if (!invmat4(ixfm, xfm))
                                objerror(ob, INTERNAL,
                                        "cannot invert BSDF transform");
                        if (!(il->flags & IL_LIGHT))
                                new_discount();
                }
                dim[0] = random();
                for (i = 0; i < il->nsamps; i++) {
                                        /* randomize location */
                    h = dim[0] + samplendx++;
                    multisamp(sp, 2, urand(h));
                    r3 = sqrt(CO_R0(co)*CO_R0(co) +
                            sp[0]*(CO_R1(co)*CO_R1(co) - CO_R0(co)*CO_R0(co)));
                    r2 = 2.*PI*sp[1];
                    r1 = r3*cos(r2);
                    r2 = r3*sin(r2);
                    for (j = 0; j < 3; j++)
                        org[j] = CO_P0(co)[j] + r1*u[j] + r2*v[j];
                                        /* sample source rays */
                    srcsamps(il, org, co->ad, ixfm);
                }
        }
                                /* wait for all rays to finish */
        rayclean();
        if (il->sd != NULL) {   /* run distribution through BSDF */
                nalt = sqrt(il->sd->nout/PI) + .5;
                nazi = PI*nalt + .5;
                redistribute(il->sd, nalt, nazi, u, v, co->ad, xfm);
                done_discount();
                if (!il->sampdens)
                        il->sampdens = nalt*nazi/PI + .999;
        }
                                /* write out the ring and its distribution */
        if (average(il, distarr, n)) {
                if (il->sampdens > 0)
                        flatout(il, distarr, nalt, nazi, u, v, co->ad);
                illumout(il, ob);
        } else
                printobj(il->altmat, ob);
                                /* clean up */
        freecone(ob);
        return(1);
}
Revision:	2.30
Committed:	Thu May 28 18:38:52 2009 UTC (14 years, 11 months ago) by greg
Content type:	text/plain
Branch:	MAIN
Changes since 2.29:	+2 -1 lines
Log Message:	Bug fix in source sampling
#	User	Rev	Content
1	greg	1.1	#ifndef lint
2	greg	2.30	static const char RCSid[] = "$Id: mkillum2.c,v 2.29 2009/03/04 00:12:25 greg Exp $";
3	greg	1.1	#endif
4			/*
5	greg	1.4	* Routines to do the actual calculation for mkillum
6	greg	1.1	*/
7
8	schorsch	2.11	#include <string.h>
9
10	greg	1.1	#include "mkillum.h"
11			#include "face.h"
12			#include "cone.h"
13	greg	2.25	#include "source.h"
14	greg	1.1
15	greg	2.13
16	greg	2.21	COLORV * distarr = NULL; /* distribution array */
17			int distsiz = 0;
18	greg	2.29	COLORV * direct_discount = NULL; /* amount to take off direct */
19	greg	2.16
20	greg	2.21	void
21	greg	2.18	newdist( /* allocate & clear distribution array */
22			int siz
23			)
24			{
25	greg	2.24	if (siz <= 0) {
26	greg	2.18	if (distsiz > 0)
27			free((void *)distarr);
28			distarr = NULL;
29			distsiz = 0;
30			return;
31			}
32			if (distsiz < siz) {
33	greg	2.21	if (distsiz > 0)
34			free((void *)distarr);
35			distarr = (COLORV )malloc(sizeof(COLOR)siz);
36	greg	2.18	if (distarr == NULL)
37	greg	2.20	error(SYSTEM, "out of memory in newdist");
38	greg	2.18	distsiz = siz;
39			}
40	greg	2.21	memset(distarr, '\0', sizeof(COLOR)*siz);
41	greg	2.18	}
42
43
44	greg	2.29	static void
45			new_discount() /* allocate space for direct contrib. record */
46			{
47			if (distsiz <= 0)
48			return;
49			direct_discount = (COLORV *)calloc(distsiz, sizeof(COLOR));
50			if (direct_discount == NULL)
51			error(SYSTEM, "out of memory in new_discount");
52			}
53
54
55			static void
56			done_discount() /* clear off direct contrib. record */
57			{
58			if (direct_discount == NULL)
59			return;
60			free((void *)direct_discount);
61			direct_discount = NULL;
62			}
63
64
65	greg	2.21	int
66	greg	2.25	process_ray( /* process a ray result or report error */
67			RAY *r,
68			int rv
69			)
70	greg	2.18	{
71			COLORV *colp;
72
73	greg	2.24	if (rv == 0) /* no result ready */
74	greg	2.18	return(0);
75			if (rv < 0)
76	greg	2.20	error(USER, "ray tracing process died");
77	greg	2.18	if (r->rno >= distsiz)
78	greg	2.20	error(INTERNAL, "bad returned index in process_ray");
79	greg	2.25	multcolor(r->rcol, r->rcoef); /* in case it's a source ray */
80	greg	2.18	colp = &distarr[r->rno * 3];
81			addcolor(colp, r->rcol);
82	greg	2.29	if (r->rsrc >= 0 && /* remember source contrib. */
83			direct_discount != NULL) {
84			colp = &direct_discount[r->rno * 3];
85			addcolor(colp, r->rcol);
86			}
87	greg	2.18	return(1);
88			}
89
90
91	greg	2.21	void
92	greg	2.25	raysamp( /* queue a ray sample */
93	greg	2.18	int ndx,
94			FVECT org,
95			FVECT dir
96	greg	2.16	)
97			{
98	greg	2.18	RAY myRay;
99			int rv;
100
101			if ((ndx < 0) \| (ndx >= distsiz))
102	greg	2.20	error(INTERNAL, "bad index in raysamp");
103	greg	2.18	VCOPY(myRay.rorg, org);
104			VCOPY(myRay.rdir, dir);
105			myRay.rmax = .0;
106			rayorigin(&myRay, PRIMARY, NULL, NULL);
107			myRay.rno = ndx;
108			/* queue ray, check result */
109			process_ray(&myRay, ray_pqueue(&myRay));
110			}
111
112
113	greg	2.21	void
114	greg	2.25	srcsamps( /* sample sources from this surface position */
115			struct illum_args *il,
116			FVECT org,
117			FVECT nrm,
118			MAT4 ixfm
119			)
120			{
121			int nalt, nazi;
122			SRCINDEX si;
123			RAY sr;
124			FVECT v;
125			double d;
126			int i, j;
127			/* get sampling density */
128			if (il->sampdens <= 0) {
129			nalt = nazi = 1;
130			} else {
131			i = PI * il->sampdens;
132			nalt = sqrt(i/PI) + .5;
133			nazi = PI*nalt + .5;
134			}
135			initsrcindex(&si); /* loop over (sub)sources */
136			for ( ; ; ) {
137			VCOPY(sr.rorg, org); /* pick side to shoot from */
138			if (il->sd != NULL) {
139			int sn = si.sn;
140			if (si.sp+1 >= si.np) ++sn;
141			if (sn >= nsources) break;
142			if (source[sn].sflags & SDISTANT)
143			d = DOT(source[sn].sloc, nrm);
144			else {
145			VSUB(v, source[sn].sloc, org);
146			d = DOT(v, nrm);
147			}
148			} else
149			d = 1.0; /* only transmission */
150			if (d < 0.0)
151			d = -1.0001il->thick - 5.FTINY;
152			else
153			d = 5.*FTINY;
154			for (i = 3; i--; )
155			sr.rorg[i] += d*nrm[i];
156	greg	2.30	samplendx++; /* increment sample counter */
157	greg	2.25	if (!srcray(&sr, NULL, &si))
158			break; /* end of sources */
159			/* index direction */
160			if (ixfm != NULL)
161			multv3(v, sr.rdir, ixfm);
162			else
163			VCOPY(v, sr.rdir);
164			if (il->sd != NULL) {
165			i = getBSDF_incndx(il->sd, v);
166			if (i < 0)
167			continue; /* must not be important */
168			sr.rno = i;
169	greg	2.26	d = 1.0/getBSDF_incohm(il->sd, i);
170	greg	2.25	} else {
171			if (v[2] >= -FTINY)
172			continue; /* only sample transmission */
173	greg	2.29	v[0] = -v[0]; v[1] = -v[1]; v[2] = -v[2];
174			sr.rno = flatindex(v, nalt, nazi);
175			d = naltnazi(1./PI) * v[2];
176	greg	2.25	}
177			d = si.dom; / solid angle correction */
178			scalecolor(sr.rcoef, d);
179			process_ray(&sr, ray_pqueue(&sr));
180			}
181			}
182
183
184			void
185	greg	2.18	rayclean() /* finish all pending rays */
186			{
187			RAY myRay;
188
189			while (process_ray(&myRay, ray_presult(&myRay, 0)))
190	greg	2.16	;
191			}
192	schorsch	2.12
193
194	greg	2.21	static void
195			mkaxes( /* compute u and v to go with n */
196			FVECT u,
197			FVECT v,
198			FVECT n
199			)
200			{
201			register int i;
202
203			v[0] = v[1] = v[2] = 0.0;
204			for (i = 0; i < 3; i++)
205			if (n[i] < 0.6 && n[i] > -0.6)
206			break;
207			v[i] = 1.0;
208			fcross(u, v, n);
209			normalize(u);
210			fcross(v, n, u);
211			}
212
213
214			static void
215			rounddir( /* compute uniform spherical direction */
216			register FVECT dv,
217			double alt,
218			double azi
219			)
220			{
221			double d1, d2;
222
223			dv[2] = 1. - 2.*alt;
224			d1 = sqrt(1. - dv[2]*dv[2]);
225			d2 = 2.PI azi;
226			dv[0] = d1*cos(d2);
227			dv[1] = d1*sin(d2);
228			}
229
230
231	greg	2.24	void
232	greg	2.21	flatdir( /* compute uniform hemispherical direction */
233	greg	2.24	FVECT dv,
234	greg	2.21	double alt,
235			double azi
236			)
237			{
238			double d1, d2;
239
240			d1 = sqrt(alt);
241			d2 = 2.PI azi;
242			dv[0] = d1*cos(d2);
243			dv[1] = d1*sin(d2);
244			dv[2] = sqrt(1. - alt);
245			}
246
247	greg	2.29	int
248			flatindex( /* compute index for hemispherical direction */
249			FVECT dv,
250			int nalt,
251			int nazi
252			)
253			{
254			double d;
255			int i, j;
256
257			d = 1.0 - dv[2]*dv[2];
258			i = d*nalt;
259			d = atan2(dv[1], dv[0]) * (0.5/PI);
260			if (d < 0.0) d += 1.0;
261			j = d*nazi + 0.5;
262			if (j >= nazi) j = 0;
263			return(i*nazi + j);
264			}
265
266	greg	2.21
267	greg	2.19	int
268	greg	2.18	my_default( /* default illum action */
269	schorsch	2.12	OBJREC *ob,
270			struct illum_args *il,
271			char *nm
272			)
273	greg	1.1	{
274	greg	1.2	sprintf(errmsg, "(%s): cannot make illum for %s \"%s\"",
275			nm, ofun[ob->otype].funame, ob->oname);
276			error(WARNING, errmsg);
277	greg	2.2	printobj(il->altmat, ob);
278	greg	2.13	return(1);
279	greg	1.2	}
280
281
282	greg	2.13	int
283	greg	2.18	my_face( /* make an illum face */
284	schorsch	2.12	OBJREC *ob,
285			struct illum_args *il,
286			char *nm
287			)
288	greg	1.2	{
289	greg	2.21	int dim[2];
290	greg	2.25	int n, nalt, nazi, alti;
291	greg	1.10	double sp[2], r1, r2;
292	greg	2.25	int h;
293	greg	1.4	FVECT dn, org, dir;
294	greg	1.3	FVECT u, v;
295			double ur[2], vr[2];
296	greg	2.21	MAT4 xfm;
297	greg	2.25	int nallow;
298	greg	2.21	FACE *fa;
299	greg	2.25	int i, j;
300	greg	1.3	/* get/check arguments */
301			fa = getface(ob);
302			if (fa->area == 0.0) {
303			freeface(ob);
304	greg	2.19	return(my_default(ob, il, nm));
305	greg	1.3	}
306			/* set up sampling */
307	greg	2.21	if (il->sd != NULL) {
308			if (!getBSDF_xfm(xfm, fa->norm, il->udir)) {
309			objerror(ob, WARNING, "illegal up direction");
310			freeface(ob);
311			return(my_default(ob, il, nm));
312			}
313			n = il->sd->ninc;
314	greg	2.22	} else {
315			if (il->sampdens <= 0) {
316			nalt = nazi = 1; /* diffuse assumption */
317			} else {
318			n = PI * il->sampdens;
319			nalt = sqrt(n/PI) + .5;
320			nazi = PI*nalt + .5;
321			}
322	greg	2.21	n = nazi*nalt;
323	greg	2.22	}
324	greg	2.18	newdist(n);
325	greg	2.20	/* take first edge >= sqrt(area) */
326	greg	2.4	for (j = fa->nv-1, i = 0; i < fa->nv; j = i++) {
327			u[0] = VERTEX(fa,i)[0] - VERTEX(fa,j)[0];
328			u[1] = VERTEX(fa,i)[1] - VERTEX(fa,j)[1];
329			u[2] = VERTEX(fa,i)[2] - VERTEX(fa,j)[2];
330	greg	2.5	if ((r1 = DOT(u,u)) >= fa->area-FTINY)
331	greg	2.3	break;
332			}
333			if (i < fa->nv) { /* got one! -- let's align our axes */
334	greg	2.5	r2 = 1.0/sqrt(r1);
335			u[0] = r2; u[1] = r2; u[2] *= r2;
336	greg	2.3	fcross(v, fa->norm, u);
337			} else /* oh well, we'll just have to wing it */
338			mkaxes(u, v, fa->norm);
339			/* now, find limits in (u,v) coordinates */
340	greg	1.3	ur[0] = vr[0] = FHUGE;
341			ur[1] = vr[1] = -FHUGE;
342			for (i = 0; i < fa->nv; i++) {
343			r1 = DOT(VERTEX(fa,i),u);
344			if (r1 < ur[0]) ur[0] = r1;
345			if (r1 > ur[1]) ur[1] = r1;
346			r2 = DOT(VERTEX(fa,i),v);
347			if (r2 < vr[0]) vr[0] = r2;
348			if (r2 > vr[1]) vr[1] = r2;
349			}
350			dim[0] = random();
351			/* sample polygon */
352	greg	2.25	nallow = 5nil->nsamps;
353	greg	2.21	for (dim[1] = 0; dim[1] < n; dim[1]++)
354	greg	1.3	for (i = 0; i < il->nsamps; i++) {
355	greg	2.23	/* randomize direction */
356	greg	2.21	h = ilhash(dim, 2) + i;
357			if (il->sd != NULL) {
358			r_BSDF_incvec(dir, il->sd, dim[1], urand(h), xfm);
359			} else {
360			multisamp(sp, 2, urand(h));
361			alti = dim[1]/nazi;
362			r1 = (alti + sp[0])/nalt;
363			r2 = (dim[1] - alti*nazi + sp[1] - .5)/nazi;
364			flatdir(dn, r1, r2);
365			for (j = 0; j < 3; j++)
366			dir[j] = -dn[0]u[j] - dn[1]v[j] -
367			dn[2]*fa->norm[j];
368			}
369	greg	2.23	/* randomize location */
370	greg	1.3	do {
371	greg	2.25	multisamp(sp, 2, urand(h+4862+nallow));
372	greg	1.10	r1 = ur[0] + (ur[1]-ur[0]) * sp[0];
373			r2 = vr[0] + (vr[1]-vr[0]) * sp[1];
374	greg	1.3	for (j = 0; j < 3; j++)
375			org[j] = r1u[j] + r2v[j]
376			+ fa->offset*fa->norm[j];
377	greg	2.25	} while (!inface(org, fa) && nallow-- > 0);
378			if (nallow < 0) {
379	greg	1.3	objerror(ob, WARNING, "bad aspect");
380	greg	2.18	rayclean();
381	greg	1.3	freeface(ob);
382	greg	2.19	return(my_default(ob, il, nm));
383	greg	1.3	}
384	greg	2.21	if (il->sd != NULL && DOT(dir, fa->norm) < -FTINY)
385	greg	2.25	r1 = -1.0001il->thick - 5.FTINY;
386	greg	2.21	else
387	greg	2.25	r1 = 5.*FTINY;
388	greg	1.3	for (j = 0; j < 3; j++)
389	greg	2.21	org[j] += r1*fa->norm[j];
390	greg	1.3	/* send sample */
391	greg	2.21	raysamp(dim[1], org, dir);
392	greg	1.3	}
393	greg	2.25	/* add in direct component? */
394	greg	2.29	if (!directvis && (il->flags & IL_LIGHT \|\| il->sd != NULL)) {
395	greg	2.25	MAT4 ixfm;
396			if (il->sd == NULL) {
397			for (i = 3; i--; ) {
398			ixfm[i][0] = u[i];
399			ixfm[i][1] = v[i];
400			ixfm[i][2] = fa->norm[i];
401			ixfm[i][3] = 0.;
402			}
403			ixfm[3][0] = ixfm[3][1] = ixfm[3][2] = 0.;
404			ixfm[3][3] = 1.;
405	greg	2.29	} else {
406			if (!invmat4(ixfm, xfm))
407			objerror(ob, INTERNAL,
408			"cannot invert BSDF transform");
409			if (!(il->flags & IL_LIGHT))
410			new_discount();
411			}
412	greg	2.25	dim[0] = random();
413			nallow = 10*il->nsamps;
414			for (i = 0; i < il->nsamps; i++) {
415			/* randomize location */
416			h = dim[0] + samplendx++;
417			do {
418			multisamp(sp, 2, urand(h+nallow));
419			r1 = ur[0] + (ur[1]-ur[0]) * sp[0];
420			r2 = vr[0] + (vr[1]-vr[0]) * sp[1];
421			for (j = 0; j < 3; j++)
422			org[j] = r1u[j] + r2v[j]
423			+ fa->offset*fa->norm[j];
424			} while (!inface(org, fa) && nallow-- > 0);
425			if (nallow < 0) {
426			objerror(ob, WARNING, "bad aspect");
427			rayclean();
428			freeface(ob);
429			return(my_default(ob, il, nm));
430			}
431			/* sample source rays */
432			srcsamps(il, org, fa->norm, ixfm);
433			}
434			}
435			/* wait for all rays to finish */
436	greg	2.18	rayclean();
437	greg	2.22	if (il->sd != NULL) { /* run distribution through BSDF */
438			nalt = sqrt(il->sd->nout/PI) + .5;
439			nazi = PI*nalt + .5;
440	greg	2.21	redistribute(il->sd, nalt, nazi, u, v, fa->norm, xfm);
441	greg	2.29	done_discount();
442	greg	2.28	if (!il->sampdens)
443			il->sampdens = nalt*nazi/PI + .999;
444	greg	2.22	}
445	greg	1.11	/* write out the face and its distribution */
446	greg	2.21	if (average(il, distarr, n)) {
447	greg	1.12	if (il->sampdens > 0)
448			flatout(il, distarr, nalt, nazi, u, v, fa->norm);
449			illumout(il, ob);
450	greg	2.2	} else
451	greg	1.12	printobj(il->altmat, ob);
452	greg	1.3	/* clean up */
453			freeface(ob);
454	greg	2.15	return(0);
455	greg	1.2	}
456
457
458	greg	2.13	int
459	greg	2.18	my_sphere( /* make an illum sphere */
460	schorsch	2.12	register OBJREC *ob,
461			struct illum_args *il,
462			char *nm
463			)
464	greg	1.2	{
465	greg	1.10	int dim[3];
466	greg	1.2	int n, nalt, nazi;
467	greg	1.10	double sp[4], r1, r2, r3;
468	greg	1.4	FVECT org, dir;
469	greg	1.2	FVECT u, v;
470			register int i, j;
471			/* check arguments */
472			if (ob->oargs.nfargs != 4)
473			objerror(ob, USER, "bad # of arguments");
474			/* set up sampling */
475	greg	1.11	if (il->sampdens <= 0)
476			nalt = nazi = 1;
477			else {
478			n = 4.PI il->sampdens;
479	greg	2.7	nalt = sqrt(2./PI*n) + .5;
480			nazi = PI/2.*nalt + .5;
481	greg	1.11	}
482	greg	2.21	if (il->sd != NULL)
483			objerror(ob, WARNING, "BSDF ignored");
484	greg	1.2	n = nalt*nazi;
485	greg	2.18	newdist(n);
486	greg	1.2	dim[0] = random();
487			/* sample sphere */
488			for (dim[1] = 0; dim[1] < nalt; dim[1]++)
489	greg	1.8	for (dim[2] = 0; dim[2] < nazi; dim[2]++)
490	greg	1.2	for (i = 0; i < il->nsamps; i++) {
491	greg	1.10	/* next sample point */
492	greg	1.11	multisamp(sp, 4, urand(ilhash(dim,3)+i));
493	greg	1.2	/* random direction */
494	greg	1.10	r1 = (dim[1] + sp[0])/nalt;
495	greg	1.13	r2 = (dim[2] + sp[1] - .5)/nazi;
496	greg	1.2	rounddir(dir, r1, r2);
497			/* random location */
498	greg	1.8	mkaxes(u, v, dir); /* yuck! */
499	greg	1.10	r3 = sqrt(sp[2]);
500			r2 = 2.PIsp[3];
501	greg	1.5	r1 = r3ob->oargs.farg[3]cos(r2);
502			r2 = r3ob->oargs.farg[3]sin(r2);
503			r3 = ob->oargs.farg[3]sqrt(1.01-r3r3);
504			for (j = 0; j < 3; j++) {
505			org[j] = ob->oargs.farg[j] + r1u[j] + r2v[j] +
506			r3*dir[j];
507			dir[j] = -dir[j];
508			}
509	greg	1.2	/* send sample */
510	greg	2.18	raysamp(dim[1]*nazi+dim[2], org, dir);
511	greg	1.2	}
512	greg	2.25	/* wait for all rays to finish */
513	greg	2.18	rayclean();
514	greg	1.11	/* write out the sphere and its distribution */
515	greg	2.21	if (average(il, distarr, n)) {
516	greg	1.12	if (il->sampdens > 0)
517			roundout(il, distarr, nalt, nazi);
518			else
519			objerror(ob, WARNING, "diffuse distribution");
520			illumout(il, ob);
521	greg	2.2	} else
522	greg	1.12	printobj(il->altmat, ob);
523	greg	1.2	/* clean up */
524	greg	2.13	return(1);
525	greg	1.2	}
526
527
528	greg	2.13	int
529	greg	2.18	my_ring( /* make an illum ring */
530	schorsch	2.12	OBJREC *ob,
531			struct illum_args *il,
532			char *nm
533			)
534	greg	1.2	{
535	greg	2.21	int dim[2];
536			int n, nalt, nazi, alti;
537			double sp[2], r1, r2, r3;
538			int h;
539	greg	1.4	FVECT dn, org, dir;
540	greg	1.3	FVECT u, v;
541	greg	2.21	MAT4 xfm;
542			CONE *co;
543	greg	2.25	int i, j;
544	greg	1.3	/* get/check arguments */
545			co = getcone(ob, 0);
546			/* set up sampling */
547	greg	2.21	if (il->sd != NULL) {
548			if (!getBSDF_xfm(xfm, co->ad, il->udir)) {
549			objerror(ob, WARNING, "illegal up direction");
550			freecone(ob);
551			return(my_default(ob, il, nm));
552			}
553			n = il->sd->ninc;
554	greg	2.22	} else {
555			if (il->sampdens <= 0) {
556			nalt = nazi = 1; /* diffuse assumption */
557			} else {
558			n = PI * il->sampdens;
559			nalt = sqrt(n/PI) + .5;
560			nazi = PI*nalt + .5;
561			}
562	greg	2.21	n = nazi*nalt;
563	greg	2.22	}
564	greg	2.18	newdist(n);
565	greg	1.3	mkaxes(u, v, co->ad);
566			dim[0] = random();
567			/* sample disk */
568	greg	2.21	for (dim[1] = 0; dim[1] < n; dim[1]++)
569	greg	1.3	for (i = 0; i < il->nsamps; i++) {
570	greg	1.10	/* next sample point */
571	greg	2.21	h = ilhash(dim,2) + i;
572	greg	2.23	/* randomize direction */
573	greg	2.21	if (il->sd != NULL) {
574			r_BSDF_incvec(dir, il->sd, dim[1], urand(h), xfm);
575			} else {
576			multisamp(sp, 2, urand(h));
577			alti = dim[1]/nazi;
578			r1 = (alti + sp[0])/nalt;
579			r2 = (dim[1] - alti*nazi + sp[1] - .5)/nazi;
580			flatdir(dn, r1, r2);
581			for (j = 0; j < 3; j++)
582	greg	2.24	dir[j] = -dn[0]u[j] - dn[1]v[j] - dn[2]*co->ad[j];
583	greg	2.21	}
584	greg	2.23	/* randomize location */
585	greg	2.21	multisamp(sp, 2, urand(h+8371));
586	greg	1.5	r3 = sqrt(CO_R0(co)*CO_R0(co) +
587	greg	2.21	sp[0](CO_R1(co)CO_R1(co) - CO_R0(co)*CO_R0(co)));
588			r2 = 2.PIsp[1];
589	greg	1.5	r1 = r3*cos(r2);
590			r2 = r3*sin(r2);
591	greg	2.21	if (il->sd != NULL && DOT(dir, co->ad) < -FTINY)
592	greg	2.25	r3 = -1.0001il->thick - 5.FTINY;
593	greg	2.21	else
594	greg	2.25	r3 = 5.*FTINY;
595	greg	1.3	for (j = 0; j < 3; j++)
596	greg	2.6	org[j] = CO_P0(co)[j] + r1u[j] + r2v[j] +
597	greg	2.21	r3*co->ad[j];
598	greg	1.3	/* send sample */
599	greg	2.21	raysamp(dim[1], org, dir);
600	greg	1.3	}
601	greg	2.25	/* add in direct component? */
602	greg	2.29	if (!directvis && (il->flags & IL_LIGHT \|\| il->sd != NULL)) {
603	greg	2.25	MAT4 ixfm;
604			if (il->sd == NULL) {
605			for (i = 3; i--; ) {
606			ixfm[i][0] = u[i];
607			ixfm[i][1] = v[i];
608			ixfm[i][2] = co->ad[i];
609			ixfm[i][3] = 0.;
610			}
611			ixfm[3][0] = ixfm[3][1] = ixfm[3][2] = 0.;
612			ixfm[3][3] = 1.;
613	greg	2.29	} else {
614			if (!invmat4(ixfm, xfm))
615			objerror(ob, INTERNAL,
616			"cannot invert BSDF transform");
617			if (!(il->flags & IL_LIGHT))
618			new_discount();
619			}
620	greg	2.25	dim[0] = random();
621			for (i = 0; i < il->nsamps; i++) {
622			/* randomize location */
623			h = dim[0] + samplendx++;
624			multisamp(sp, 2, urand(h));
625			r3 = sqrt(CO_R0(co)*CO_R0(co) +
626			sp[0](CO_R1(co)CO_R1(co) - CO_R0(co)*CO_R0(co)));
627			r2 = 2.PIsp[1];
628			r1 = r3*cos(r2);
629			r2 = r3*sin(r2);
630			for (j = 0; j < 3; j++)
631			org[j] = CO_P0(co)[j] + r1u[j] + r2v[j];
632			/* sample source rays */
633			srcsamps(il, org, co->ad, ixfm);
634			}
635			}
636			/* wait for all rays to finish */
637	greg	2.18	rayclean();
638	greg	2.22	if (il->sd != NULL) { /* run distribution through BSDF */
639			nalt = sqrt(il->sd->nout/PI) + .5;
640			nazi = PI*nalt + .5;
641	greg	2.21	redistribute(il->sd, nalt, nazi, u, v, co->ad, xfm);
642	greg	2.29	done_discount();
643	greg	2.28	if (!il->sampdens)
644			il->sampdens = nalt*nazi/PI + .999;
645	greg	2.22	}
646	greg	1.11	/* write out the ring and its distribution */
647	greg	2.21	if (average(il, distarr, n)) {
648	greg	1.12	if (il->sampdens > 0)
649			flatout(il, distarr, nalt, nazi, u, v, co->ad);
650			illumout(il, ob);
651	greg	2.2	} else
652	greg	1.12	printobj(il->altmat, ob);
653	greg	1.3	/* clean up */
654			freecone(ob);
655	greg	2.13	return(1);
656	greg	1.2	}