src/gen/mkillum2.c

#ifndef lint
static const char       RCSid[] = "$Id: mkillum2.c,v 2.24 2007/12/05 20:07:34 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;


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);
}


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);
        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];
                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 = getBSDF_incrad(il->sd, i);
                        d = 1.0/(PI*d*d);
                } else {
                        if (v[2] >= -FTINY)
                                continue;       /* only sample transmission */
                        d = 1.0 - v[2]*v[2];
                        i = d*nalt;
                        d = atan2(-v[1], -v[0])/(2.*PI);
                        if (d < 0.0) d += 1.0;
                        j = d*nazi + 0.5;
                        if (j >= nazi) j = 0;
                        sr.rno = i*nazi + j;
                        d = nalt*nazi/PI;
                }
                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
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) {
                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");
                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);
        }
                                /* 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) {
                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");
                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);
        }
                                /* 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:	2.25
Committed:	Thu Dec 6 19:40:43 2007 UTC (16 years, 4 months ago) by greg
Content type:	text/plain
Branch:	MAIN
Changes since 2.24:	+167 -18 lines
Log Message:	Added light source sampling when l+ and -dv- are set
#	User	Rev	Content
1	greg	1.1	#ifndef lint
2	greg	2.25	static const char RCSid[] = "$Id: mkillum2.c,v 2.24 2007/12/05 20:07:34 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	2.16
19
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	2.21	int
45	greg	2.25	process_ray( /* process a ray result or report error */
46			RAY *r,
47			int rv
48			)
49	greg	2.18	{
50			COLORV *colp;
51
52	greg	2.24	if (rv == 0) /* no result ready */
53	greg	2.18	return(0);
54			if (rv < 0)
55	greg	2.20	error(USER, "ray tracing process died");
56	greg	2.18	if (r->rno >= distsiz)
57	greg	2.20	error(INTERNAL, "bad returned index in process_ray");
58	greg	2.25	multcolor(r->rcol, r->rcoef); /* in case it's a source ray */
59	greg	2.18	colp = &distarr[r->rno * 3];
60			addcolor(colp, r->rcol);
61			return(1);
62			}
63
64
65	greg	2.21	void
66	greg	2.25	raysamp( /* queue a ray sample */
67	greg	2.18	int ndx,
68			FVECT org,
69			FVECT dir
70	greg	2.16	)
71			{
72	greg	2.18	RAY myRay;
73			int rv;
74
75			if ((ndx < 0) \| (ndx >= distsiz))
76	greg	2.20	error(INTERNAL, "bad index in raysamp");
77	greg	2.18	VCOPY(myRay.rorg, org);
78			VCOPY(myRay.rdir, dir);
79			myRay.rmax = .0;
80			rayorigin(&myRay, PRIMARY, NULL, NULL);
81			myRay.rno = ndx;
82			/* queue ray, check result */
83			process_ray(&myRay, ray_pqueue(&myRay));
84			}
85
86
87	greg	2.21	void
88	greg	2.25	srcsamps( /* sample sources from this surface position */
89			struct illum_args *il,
90			FVECT org,
91			FVECT nrm,
92			MAT4 ixfm
93			)
94			{
95			int nalt, nazi;
96			SRCINDEX si;
97			RAY sr;
98			FVECT v;
99			double d;
100			int i, j;
101			/* get sampling density */
102			if (il->sampdens <= 0) {
103			nalt = nazi = 1;
104			} else {
105			i = PI * il->sampdens;
106			nalt = sqrt(i/PI) + .5;
107			nazi = PI*nalt + .5;
108			}
109			initsrcindex(&si); /* loop over (sub)sources */
110			for ( ; ; ) {
111			VCOPY(sr.rorg, org); /* pick side to shoot from */
112			if (il->sd != NULL) {
113			int sn = si.sn;
114			if (si.sp+1 >= si.np) ++sn;
115			if (sn >= nsources) break;
116			if (source[sn].sflags & SDISTANT)
117			d = DOT(source[sn].sloc, nrm);
118			else {
119			VSUB(v, source[sn].sloc, org);
120			d = DOT(v, nrm);
121			}
122			} else
123			d = 1.0; /* only transmission */
124			if (d < 0.0)
125			d = -1.0001il->thick - 5.FTINY;
126			else
127			d = 5.*FTINY;
128			for (i = 3; i--; )
129			sr.rorg[i] += d*nrm[i];
130			if (!srcray(&sr, NULL, &si))
131			break; /* end of sources */
132			/* index direction */
133			if (ixfm != NULL)
134			multv3(v, sr.rdir, ixfm);
135			else
136			VCOPY(v, sr.rdir);
137			if (il->sd != NULL) {
138			i = getBSDF_incndx(il->sd, v);
139			if (i < 0)
140			continue; /* must not be important */
141			sr.rno = i;
142			d = getBSDF_incrad(il->sd, i);
143			d = 1.0/(PIdd);
144			} else {
145			if (v[2] >= -FTINY)
146			continue; /* only sample transmission */
147			d = 1.0 - v[2]*v[2];
148			i = d*nalt;
149			d = atan2(-v[1], -v[0])/(2.*PI);
150			if (d < 0.0) d += 1.0;
151			j = d*nazi + 0.5;
152			if (j >= nazi) j = 0;
153			sr.rno = i*nazi + j;
154			d = nalt*nazi/PI;
155			}
156			d = si.dom; / solid angle correction */
157			scalecolor(sr.rcoef, d);
158			process_ray(&sr, ray_pqueue(&sr));
159			}
160			}
161
162
163			void
164	greg	2.18	rayclean() /* finish all pending rays */
165			{
166			RAY myRay;
167
168			while (process_ray(&myRay, ray_presult(&myRay, 0)))
169	greg	2.16	;
170			}
171	schorsch	2.12
172
173	greg	2.21	static void
174			mkaxes( /* compute u and v to go with n */
175			FVECT u,
176			FVECT v,
177			FVECT n
178			)
179			{
180			register int i;
181
182			v[0] = v[1] = v[2] = 0.0;
183			for (i = 0; i < 3; i++)
184			if (n[i] < 0.6 && n[i] > -0.6)
185			break;
186			v[i] = 1.0;
187			fcross(u, v, n);
188			normalize(u);
189			fcross(v, n, u);
190			}
191
192
193			static void
194			rounddir( /* compute uniform spherical direction */
195			register FVECT dv,
196			double alt,
197			double azi
198			)
199			{
200			double d1, d2;
201
202			dv[2] = 1. - 2.*alt;
203			d1 = sqrt(1. - dv[2]*dv[2]);
204			d2 = 2.PI azi;
205			dv[0] = d1*cos(d2);
206			dv[1] = d1*sin(d2);
207			}
208
209
210	greg	2.24	void
211	greg	2.21	flatdir( /* compute uniform hemispherical direction */
212	greg	2.24	FVECT dv,
213	greg	2.21	double alt,
214			double azi
215			)
216			{
217			double d1, d2;
218
219			d1 = sqrt(alt);
220			d2 = 2.PI azi;
221			dv[0] = d1*cos(d2);
222			dv[1] = d1*sin(d2);
223			dv[2] = sqrt(1. - alt);
224			}
225
226
227	greg	2.19	int
228	greg	2.18	my_default( /* default illum action */
229	schorsch	2.12	OBJREC *ob,
230			struct illum_args *il,
231			char *nm
232			)
233	greg	1.1	{
234	greg	1.2	sprintf(errmsg, "(%s): cannot make illum for %s \"%s\"",
235			nm, ofun[ob->otype].funame, ob->oname);
236			error(WARNING, errmsg);
237	greg	2.2	printobj(il->altmat, ob);
238	greg	2.13	return(1);
239	greg	1.2	}
240
241
242	greg	2.13	int
243	greg	2.18	my_face( /* make an illum face */
244	schorsch	2.12	OBJREC *ob,
245			struct illum_args *il,
246			char *nm
247			)
248	greg	1.2	{
249	greg	2.21	int dim[2];
250	greg	2.25	int n, nalt, nazi, alti;
251	greg	1.10	double sp[2], r1, r2;
252	greg	2.25	int h;
253	greg	1.4	FVECT dn, org, dir;
254	greg	1.3	FVECT u, v;
255			double ur[2], vr[2];
256	greg	2.21	MAT4 xfm;
257	greg	2.25	int nallow;
258	greg	2.21	FACE *fa;
259	greg	2.25	int i, j;
260	greg	1.3	/* get/check arguments */
261			fa = getface(ob);
262			if (fa->area == 0.0) {
263			freeface(ob);
264	greg	2.19	return(my_default(ob, il, nm));
265	greg	1.3	}
266			/* set up sampling */
267	greg	2.21	if (il->sd != NULL) {
268			if (!getBSDF_xfm(xfm, fa->norm, il->udir)) {
269			objerror(ob, WARNING, "illegal up direction");
270			freeface(ob);
271			return(my_default(ob, il, nm));
272			}
273			n = il->sd->ninc;
274	greg	2.22	} else {
275			if (il->sampdens <= 0) {
276			nalt = nazi = 1; /* diffuse assumption */
277			} else {
278			n = PI * il->sampdens;
279			nalt = sqrt(n/PI) + .5;
280			nazi = PI*nalt + .5;
281			}
282	greg	2.21	n = nazi*nalt;
283	greg	2.22	}
284	greg	2.18	newdist(n);
285	greg	2.20	/* take first edge >= sqrt(area) */
286	greg	2.4	for (j = fa->nv-1, i = 0; i < fa->nv; j = i++) {
287			u[0] = VERTEX(fa,i)[0] - VERTEX(fa,j)[0];
288			u[1] = VERTEX(fa,i)[1] - VERTEX(fa,j)[1];
289			u[2] = VERTEX(fa,i)[2] - VERTEX(fa,j)[2];
290	greg	2.5	if ((r1 = DOT(u,u)) >= fa->area-FTINY)
291	greg	2.3	break;
292			}
293			if (i < fa->nv) { /* got one! -- let's align our axes */
294	greg	2.5	r2 = 1.0/sqrt(r1);
295			u[0] = r2; u[1] = r2; u[2] *= r2;
296	greg	2.3	fcross(v, fa->norm, u);
297			} else /* oh well, we'll just have to wing it */
298			mkaxes(u, v, fa->norm);
299			/* now, find limits in (u,v) coordinates */
300	greg	1.3	ur[0] = vr[0] = FHUGE;
301			ur[1] = vr[1] = -FHUGE;
302			for (i = 0; i < fa->nv; i++) {
303			r1 = DOT(VERTEX(fa,i),u);
304			if (r1 < ur[0]) ur[0] = r1;
305			if (r1 > ur[1]) ur[1] = r1;
306			r2 = DOT(VERTEX(fa,i),v);
307			if (r2 < vr[0]) vr[0] = r2;
308			if (r2 > vr[1]) vr[1] = r2;
309			}
310			dim[0] = random();
311			/* sample polygon */
312	greg	2.25	nallow = 5nil->nsamps;
313	greg	2.21	for (dim[1] = 0; dim[1] < n; dim[1]++)
314	greg	1.3	for (i = 0; i < il->nsamps; i++) {
315	greg	2.23	/* randomize direction */
316	greg	2.21	h = ilhash(dim, 2) + i;
317			if (il->sd != NULL) {
318			r_BSDF_incvec(dir, il->sd, dim[1], urand(h), xfm);
319			} else {
320			multisamp(sp, 2, urand(h));
321			alti = dim[1]/nazi;
322			r1 = (alti + sp[0])/nalt;
323			r2 = (dim[1] - alti*nazi + sp[1] - .5)/nazi;
324			flatdir(dn, r1, r2);
325			for (j = 0; j < 3; j++)
326			dir[j] = -dn[0]u[j] - dn[1]v[j] -
327			dn[2]*fa->norm[j];
328			}
329	greg	2.23	/* randomize location */
330	greg	1.3	do {
331	greg	2.25	multisamp(sp, 2, urand(h+4862+nallow));
332	greg	1.10	r1 = ur[0] + (ur[1]-ur[0]) * sp[0];
333			r2 = vr[0] + (vr[1]-vr[0]) * sp[1];
334	greg	1.3	for (j = 0; j < 3; j++)
335			org[j] = r1u[j] + r2v[j]
336			+ fa->offset*fa->norm[j];
337	greg	2.25	} while (!inface(org, fa) && nallow-- > 0);
338			if (nallow < 0) {
339	greg	1.3	objerror(ob, WARNING, "bad aspect");
340	greg	2.18	rayclean();
341	greg	1.3	freeface(ob);
342	greg	2.19	return(my_default(ob, il, nm));
343	greg	1.3	}
344	greg	2.21	if (il->sd != NULL && DOT(dir, fa->norm) < -FTINY)
345	greg	2.25	r1 = -1.0001il->thick - 5.FTINY;
346	greg	2.21	else
347	greg	2.25	r1 = 5.*FTINY;
348	greg	1.3	for (j = 0; j < 3; j++)
349	greg	2.21	org[j] += r1*fa->norm[j];
350	greg	1.3	/* send sample */
351	greg	2.21	raysamp(dim[1], org, dir);
352	greg	1.3	}
353	greg	2.25	/* add in direct component? */
354			if (!directvis && il->flags & IL_LIGHT) {
355			MAT4 ixfm;
356			if (il->sd == NULL) {
357			for (i = 3; i--; ) {
358			ixfm[i][0] = u[i];
359			ixfm[i][1] = v[i];
360			ixfm[i][2] = fa->norm[i];
361			ixfm[i][3] = 0.;
362			}
363			ixfm[3][0] = ixfm[3][1] = ixfm[3][2] = 0.;
364			ixfm[3][3] = 1.;
365			} else if (!invmat4(ixfm, xfm))
366			objerror(ob, INTERNAL, "cannot invert BSDF transform");
367			dim[0] = random();
368			nallow = 10*il->nsamps;
369			for (i = 0; i < il->nsamps; i++) {
370			/* randomize location */
371			h = dim[0] + samplendx++;
372			do {
373			multisamp(sp, 2, urand(h+nallow));
374			r1 = ur[0] + (ur[1]-ur[0]) * sp[0];
375			r2 = vr[0] + (vr[1]-vr[0]) * sp[1];
376			for (j = 0; j < 3; j++)
377			org[j] = r1u[j] + r2v[j]
378			+ fa->offset*fa->norm[j];
379			} while (!inface(org, fa) && nallow-- > 0);
380			if (nallow < 0) {
381			objerror(ob, WARNING, "bad aspect");
382			rayclean();
383			freeface(ob);
384			return(my_default(ob, il, nm));
385			}
386			/* sample source rays */
387			srcsamps(il, org, fa->norm, ixfm);
388			}
389			}
390			/* wait for all rays to finish */
391	greg	2.18	rayclean();
392	greg	2.22	if (il->sd != NULL) { /* run distribution through BSDF */
393			nalt = sqrt(il->sd->nout/PI) + .5;
394			nazi = PI*nalt + .5;
395	greg	2.21	redistribute(il->sd, nalt, nazi, u, v, fa->norm, xfm);
396	greg	2.22	}
397	greg	1.11	/* write out the face and its distribution */
398	greg	2.21	if (average(il, distarr, n)) {
399	greg	1.12	if (il->sampdens > 0)
400			flatout(il, distarr, nalt, nazi, u, v, fa->norm);
401			illumout(il, ob);
402	greg	2.2	} else
403	greg	1.12	printobj(il->altmat, ob);
404	greg	1.3	/* clean up */
405			freeface(ob);
406	greg	2.15	return(0);
407	greg	1.2	}
408
409
410	greg	2.13	int
411	greg	2.18	my_sphere( /* make an illum sphere */
412	schorsch	2.12	register OBJREC *ob,
413			struct illum_args *il,
414			char *nm
415			)
416	greg	1.2	{
417	greg	1.10	int dim[3];
418	greg	1.2	int n, nalt, nazi;
419	greg	1.10	double sp[4], r1, r2, r3;
420	greg	1.4	FVECT org, dir;
421	greg	1.2	FVECT u, v;
422			register int i, j;
423			/* check arguments */
424			if (ob->oargs.nfargs != 4)
425			objerror(ob, USER, "bad # of arguments");
426			/* set up sampling */
427	greg	1.11	if (il->sampdens <= 0)
428			nalt = nazi = 1;
429			else {
430			n = 4.PI il->sampdens;
431	greg	2.7	nalt = sqrt(2./PI*n) + .5;
432			nazi = PI/2.*nalt + .5;
433	greg	1.11	}
434	greg	2.21	if (il->sd != NULL)
435			objerror(ob, WARNING, "BSDF ignored");
436	greg	1.2	n = nalt*nazi;
437	greg	2.18	newdist(n);
438	greg	1.2	dim[0] = random();
439			/* sample sphere */
440			for (dim[1] = 0; dim[1] < nalt; dim[1]++)
441	greg	1.8	for (dim[2] = 0; dim[2] < nazi; dim[2]++)
442	greg	1.2	for (i = 0; i < il->nsamps; i++) {
443	greg	1.10	/* next sample point */
444	greg	1.11	multisamp(sp, 4, urand(ilhash(dim,3)+i));
445	greg	1.2	/* random direction */
446	greg	1.10	r1 = (dim[1] + sp[0])/nalt;
447	greg	1.13	r2 = (dim[2] + sp[1] - .5)/nazi;
448	greg	1.2	rounddir(dir, r1, r2);
449			/* random location */
450	greg	1.8	mkaxes(u, v, dir); /* yuck! */
451	greg	1.10	r3 = sqrt(sp[2]);
452			r2 = 2.PIsp[3];
453	greg	1.5	r1 = r3ob->oargs.farg[3]cos(r2);
454			r2 = r3ob->oargs.farg[3]sin(r2);
455			r3 = ob->oargs.farg[3]sqrt(1.01-r3r3);
456			for (j = 0; j < 3; j++) {
457			org[j] = ob->oargs.farg[j] + r1u[j] + r2v[j] +
458			r3*dir[j];
459			dir[j] = -dir[j];
460			}
461	greg	1.2	/* send sample */
462	greg	2.18	raysamp(dim[1]*nazi+dim[2], org, dir);
463	greg	1.2	}
464	greg	2.25	/* wait for all rays to finish */
465	greg	2.18	rayclean();
466	greg	1.11	/* write out the sphere and its distribution */
467	greg	2.21	if (average(il, distarr, n)) {
468	greg	1.12	if (il->sampdens > 0)
469			roundout(il, distarr, nalt, nazi);
470			else
471			objerror(ob, WARNING, "diffuse distribution");
472			illumout(il, ob);
473	greg	2.2	} else
474	greg	1.12	printobj(il->altmat, ob);
475	greg	1.2	/* clean up */
476	greg	2.13	return(1);
477	greg	1.2	}
478
479
480	greg	2.13	int
481	greg	2.18	my_ring( /* make an illum ring */
482	schorsch	2.12	OBJREC *ob,
483			struct illum_args *il,
484			char *nm
485			)
486	greg	1.2	{
487	greg	2.21	int dim[2];
488			int n, nalt, nazi, alti;
489			double sp[2], r1, r2, r3;
490			int h;
491	greg	1.4	FVECT dn, org, dir;
492	greg	1.3	FVECT u, v;
493	greg	2.21	MAT4 xfm;
494			CONE *co;
495	greg	2.25	int i, j;
496	greg	1.3	/* get/check arguments */
497			co = getcone(ob, 0);
498			/* set up sampling */
499	greg	2.21	if (il->sd != NULL) {
500			if (!getBSDF_xfm(xfm, co->ad, il->udir)) {
501			objerror(ob, WARNING, "illegal up direction");
502			freecone(ob);
503			return(my_default(ob, il, nm));
504			}
505			n = il->sd->ninc;
506	greg	2.22	} else {
507			if (il->sampdens <= 0) {
508			nalt = nazi = 1; /* diffuse assumption */
509			} else {
510			n = PI * il->sampdens;
511			nalt = sqrt(n/PI) + .5;
512			nazi = PI*nalt + .5;
513			}
514	greg	2.21	n = nazi*nalt;
515	greg	2.22	}
516	greg	2.18	newdist(n);
517	greg	1.3	mkaxes(u, v, co->ad);
518			dim[0] = random();
519			/* sample disk */
520	greg	2.21	for (dim[1] = 0; dim[1] < n; dim[1]++)
521	greg	1.3	for (i = 0; i < il->nsamps; i++) {
522	greg	1.10	/* next sample point */
523	greg	2.21	h = ilhash(dim,2) + i;
524	greg	2.23	/* randomize direction */
525	greg	2.21	if (il->sd != NULL) {
526			r_BSDF_incvec(dir, il->sd, dim[1], urand(h), xfm);
527			} else {
528			multisamp(sp, 2, urand(h));
529			alti = dim[1]/nazi;
530			r1 = (alti + sp[0])/nalt;
531			r2 = (dim[1] - alti*nazi + sp[1] - .5)/nazi;
532			flatdir(dn, r1, r2);
533			for (j = 0; j < 3; j++)
534	greg	2.24	dir[j] = -dn[0]u[j] - dn[1]v[j] - dn[2]*co->ad[j];
535	greg	2.21	}
536	greg	2.23	/* randomize location */
537	greg	2.21	multisamp(sp, 2, urand(h+8371));
538	greg	1.5	r3 = sqrt(CO_R0(co)*CO_R0(co) +
539	greg	2.21	sp[0](CO_R1(co)CO_R1(co) - CO_R0(co)*CO_R0(co)));
540			r2 = 2.PIsp[1];
541	greg	1.5	r1 = r3*cos(r2);
542			r2 = r3*sin(r2);
543	greg	2.21	if (il->sd != NULL && DOT(dir, co->ad) < -FTINY)
544	greg	2.25	r3 = -1.0001il->thick - 5.FTINY;
545	greg	2.21	else
546	greg	2.25	r3 = 5.*FTINY;
547	greg	1.3	for (j = 0; j < 3; j++)
548	greg	2.6	org[j] = CO_P0(co)[j] + r1u[j] + r2v[j] +
549	greg	2.21	r3*co->ad[j];
550	greg	1.3	/* send sample */
551	greg	2.21	raysamp(dim[1], org, dir);
552	greg	1.3	}
553	greg	2.25	/* add in direct component? */
554			if (!directvis && il->flags & IL_LIGHT) {
555			MAT4 ixfm;
556			if (il->sd == NULL) {
557			for (i = 3; i--; ) {
558			ixfm[i][0] = u[i];
559			ixfm[i][1] = v[i];
560			ixfm[i][2] = co->ad[i];
561			ixfm[i][3] = 0.;
562			}
563			ixfm[3][0] = ixfm[3][1] = ixfm[3][2] = 0.;
564			ixfm[3][3] = 1.;
565			} else if (!invmat4(ixfm, xfm))
566			objerror(ob, INTERNAL, "cannot invert BSDF transform");
567			dim[0] = random();
568			for (i = 0; i < il->nsamps; i++) {
569			/* randomize location */
570			h = dim[0] + samplendx++;
571			multisamp(sp, 2, urand(h));
572			r3 = sqrt(CO_R0(co)*CO_R0(co) +
573			sp[0](CO_R1(co)CO_R1(co) - CO_R0(co)*CO_R0(co)));
574			r2 = 2.PIsp[1];
575			r1 = r3*cos(r2);
576			r2 = r3*sin(r2);
577			for (j = 0; j < 3; j++)
578			org[j] = CO_P0(co)[j] + r1u[j] + r2v[j];
579			/* sample source rays */
580			srcsamps(il, org, co->ad, ixfm);
581			}
582			}
583			/* wait for all rays to finish */
584	greg	2.18	rayclean();
585	greg	2.22	if (il->sd != NULL) { /* run distribution through BSDF */
586			nalt = sqrt(il->sd->nout/PI) + .5;
587			nazi = PI*nalt + .5;
588	greg	2.21	redistribute(il->sd, nalt, nazi, u, v, co->ad, xfm);
589	greg	2.22	}
590	greg	1.11	/* write out the ring and its distribution */
591	greg	2.21	if (average(il, distarr, n)) {
592	greg	1.12	if (il->sampdens > 0)
593			flatout(il, distarr, nalt, nazi, u, v, co->ad);
594			illumout(il, ob);
595	greg	2.2	} else
596	greg	1.12	printobj(il->altmat, ob);
597	greg	1.3	/* clean up */
598			freecone(ob);
599	greg	2.13	return(1);
600	greg	1.2	}