src/gen/mkillum2.c

#ifndef lint
static const char       RCSid[] = "$Id: mkillum2.c,v 2.40 2015/05/21 05:54:54 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"
#include  "paths.h"

#ifndef NBSDFSAMPS
#define NBSDFSAMPS      256             /* BSDF resampling count */
#endif

COLORV *        distarr = NULL;         /* distribution array */
int             distsiz = 0;


void
newdist(                        /* allocate & clear distribution array */
        int siz
)
{
        if (siz <= 0) {
                if (distsiz > 0)
                        free(distarr);
                distarr = NULL;
                distsiz = 0;
                return;
        }
        if (distsiz < siz) {
                if (distsiz > 0)
                        free(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|SPECULAR, 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,
        double eps,
        MAT4 ixfm
)
{
        int  nalt=1, nazi=1;
        SRCINDEX  si;
        RAY  sr;
        FVECT   v;
        double  d;
        int  i, j;
                                                /* get sampling density */
        if (il->sampdens > 0) {
                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 */
                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 (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);
                VSUM(sr.rorg, sr.rorg, sr.rdir, -eps);
                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
)
{
        getperpendicular(u, n, 1);
        fcross(v, n, u);
}


static void
rounddir(               /* compute uniform spherical direction */
        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];
        double  epsilon;
        MAT4  xfm;
        char  xfrot[64];
        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->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;
        epsilon = .005*sqrt(fa->area);
        for (dim[1] = 0; dim[1] < n; dim[1]++)
                for (i = 0; i < il->nsamps; i++) {
                                        /* randomize direction */
                    h = ilhash(dim, 2) + i;
                    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));
                    }
                    VSUM(org, org, dir, -epsilon);
                                        /* send sample */
                    raysamp(dim[1], org, dir);
                }
                                /* add in direct component? */
        if (il->flags & IL_LIGHT) {
                MAT4    ixfm;
                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.;
                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, epsilon, ixfm);
                }
        }
                                /* wait for all rays to finish */
        rayclean();
                                /* 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 */
        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;
        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;
        }
        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->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 */
                    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);
                    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 (il->flags & IL_LIGHT) {
                MAT4    ixfm;
                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.;
                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, 5.*FTINY, ixfm);
                }
        }
                                /* wait for all rays to finish */
        rayclean();
                                /* 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:	2.41
Committed:	Thu Sep 15 22:34:41 2016 UTC (9 years, 1 month ago) by greg
Content type:	text/plain
Branch:	MAIN
Changes since 2.40:	+9 -10 lines
Log Message:	Made mkillum more forgiving of non-planar polygons
#	User	Rev	Content
1	greg	1.1	#ifndef lint
2	greg	2.41	static const char RCSid[] = "$Id: mkillum2.c,v 2.40 2015/05/21 05:54:54 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	2.35	#include "paths.h"
15	greg	1.1
16	greg	2.31	#ifndef NBSDFSAMPS
17	greg	2.32	#define NBSDFSAMPS 256 /* BSDF resampling count */
18	greg	2.31	#endif
19	greg	2.13
20	greg	2.21	COLORV * distarr = NULL; /* distribution array */
21			int distsiz = 0;
22	greg	2.16
23	greg	2.31
24	greg	2.21	void
25	greg	2.18	newdist( /* allocate & clear distribution array */
26			int siz
27			)
28			{
29	greg	2.24	if (siz <= 0) {
30	greg	2.18	if (distsiz > 0)
31	greg	2.36	free(distarr);
32	greg	2.18	distarr = NULL;
33			distsiz = 0;
34			return;
35			}
36			if (distsiz < siz) {
37	greg	2.21	if (distsiz > 0)
38	greg	2.36	free(distarr);
39	greg	2.21	distarr = (COLORV )malloc(sizeof(COLOR)siz);
40	greg	2.18	if (distarr == NULL)
41	greg	2.20	error(SYSTEM, "out of memory in newdist");
42	greg	2.18	distsiz = siz;
43			}
44	greg	2.21	memset(distarr, '\0', sizeof(COLOR)*siz);
45	greg	2.18	}
46
47
48	greg	2.21	int
49	greg	2.25	process_ray( /* process a ray result or report error */
50			RAY *r,
51			int rv
52			)
53	greg	2.18	{
54			COLORV *colp;
55
56	greg	2.24	if (rv == 0) /* no result ready */
57	greg	2.18	return(0);
58			if (rv < 0)
59	greg	2.20	error(USER, "ray tracing process died");
60	greg	2.18	if (r->rno >= distsiz)
61	greg	2.20	error(INTERNAL, "bad returned index in process_ray");
62	greg	2.25	multcolor(r->rcol, r->rcoef); /* in case it's a source ray */
63	greg	2.18	colp = &distarr[r->rno * 3];
64			addcolor(colp, r->rcol);
65			return(1);
66			}
67
68
69	greg	2.21	void
70	greg	2.25	raysamp( /* queue a ray sample */
71	greg	2.18	int ndx,
72			FVECT org,
73			FVECT dir
74	greg	2.16	)
75			{
76	greg	2.18	RAY myRay;
77			int rv;
78
79			if ((ndx < 0) \| (ndx >= distsiz))
80	greg	2.20	error(INTERNAL, "bad index in raysamp");
81	greg	2.18	VCOPY(myRay.rorg, org);
82			VCOPY(myRay.rdir, dir);
83			myRay.rmax = .0;
84	greg	2.36	rayorigin(&myRay, PRIMARY\|SPECULAR, NULL, NULL);
85	greg	2.18	myRay.rno = ndx;
86			/* queue ray, check result */
87			process_ray(&myRay, ray_pqueue(&myRay));
88			}
89
90
91	greg	2.21	void
92	greg	2.25	srcsamps( /* sample sources from this surface position */
93			struct illum_args *il,
94			FVECT org,
95	greg	2.41	double eps,
96	greg	2.25	MAT4 ixfm
97			)
98			{
99	greg	2.37	int nalt=1, nazi=1;
100	greg	2.25	SRCINDEX si;
101			RAY sr;
102			FVECT v;
103			double d;
104			int i, j;
105			/* get sampling density */
106	greg	2.38	if (il->sampdens > 0) {
107	greg	2.25	i = PI * il->sampdens;
108			nalt = sqrt(i/PI) + .5;
109			nazi = PI*nalt + .5;
110			}
111			initsrcindex(&si); /* loop over (sub)sources */
112			for ( ; ; ) {
113			VCOPY(sr.rorg, org); /* pick side to shoot from */
114	greg	2.30	samplendx++; /* increment sample counter */
115	greg	2.25	if (!srcray(&sr, NULL, &si))
116			break; /* end of sources */
117			/* index direction */
118			if (ixfm != NULL)
119			multv3(v, sr.rdir, ixfm);
120			else
121			VCOPY(v, sr.rdir);
122	greg	2.38	if (v[2] >= -FTINY)
123	greg	2.41	continue; /* only sample transmission */
124	greg	2.38	v[0] = -v[0]; v[1] = -v[1]; v[2] = -v[2];
125			sr.rno = flatindex(v, nalt, nazi);
126			d = naltnazi(1./PI) * v[2];
127	greg	2.25	d = si.dom; / solid angle correction */
128			scalecolor(sr.rcoef, d);
129	greg	2.41	VSUM(sr.rorg, sr.rorg, sr.rdir, -eps);
130	greg	2.25	process_ray(&sr, ray_pqueue(&sr));
131			}
132			}
133
134
135			void
136	greg	2.18	rayclean() /* finish all pending rays */
137			{
138			RAY myRay;
139
140			while (process_ray(&myRay, ray_presult(&myRay, 0)))
141	greg	2.16	;
142			}
143	schorsch	2.12
144
145	greg	2.21	static void
146			mkaxes( /* compute u and v to go with n */
147			FVECT u,
148			FVECT v,
149			FVECT n
150			)
151			{
152	greg	2.40	getperpendicular(u, n, 1);
153	greg	2.21	fcross(v, n, u);
154			}
155
156
157			static void
158			rounddir( /* compute uniform spherical direction */
159	greg	2.39	FVECT dv,
160	greg	2.21	double alt,
161			double azi
162			)
163			{
164			double d1, d2;
165
166			dv[2] = 1. - 2.*alt;
167			d1 = sqrt(1. - dv[2]*dv[2]);
168			d2 = 2.PI azi;
169			dv[0] = d1*cos(d2);
170			dv[1] = d1*sin(d2);
171			}
172
173
174	greg	2.24	void
175	greg	2.21	flatdir( /* compute uniform hemispherical direction */
176	greg	2.24	FVECT dv,
177	greg	2.21	double alt,
178			double azi
179			)
180			{
181			double d1, d2;
182
183			d1 = sqrt(alt);
184			d2 = 2.PI azi;
185			dv[0] = d1*cos(d2);
186			dv[1] = d1*sin(d2);
187			dv[2] = sqrt(1. - alt);
188			}
189
190	greg	2.35
191	greg	2.29	int
192			flatindex( /* compute index for hemispherical direction */
193			FVECT dv,
194			int nalt,
195			int nazi
196			)
197			{
198			double d;
199			int i, j;
200
201			d = 1.0 - dv[2]*dv[2];
202			i = d*nalt;
203			d = atan2(dv[1], dv[0]) * (0.5/PI);
204			if (d < 0.0) d += 1.0;
205			j = d*nazi + 0.5;
206			if (j >= nazi) j = 0;
207			return(i*nazi + j);
208			}
209
210	greg	2.21
211	greg	2.19	int
212	greg	2.18	my_default( /* default illum action */
213	schorsch	2.12	OBJREC *ob,
214			struct illum_args *il,
215			char *nm
216			)
217	greg	1.1	{
218	greg	1.2	sprintf(errmsg, "(%s): cannot make illum for %s \"%s\"",
219			nm, ofun[ob->otype].funame, ob->oname);
220			error(WARNING, errmsg);
221	greg	2.2	printobj(il->altmat, ob);
222	greg	2.13	return(1);
223	greg	1.2	}
224
225
226	greg	2.13	int
227	greg	2.18	my_face( /* make an illum face */
228	schorsch	2.12	OBJREC *ob,
229			struct illum_args *il,
230			char *nm
231			)
232	greg	1.2	{
233	greg	2.21	int dim[2];
234	greg	2.25	int n, nalt, nazi, alti;
235	greg	1.10	double sp[2], r1, r2;
236	greg	2.25	int h;
237	greg	1.4	FVECT dn, org, dir;
238	greg	1.3	FVECT u, v;
239			double ur[2], vr[2];
240	greg	2.41	double epsilon;
241	greg	2.21	MAT4 xfm;
242	greg	2.35	char xfrot[64];
243	greg	2.25	int nallow;
244	greg	2.21	FACE *fa;
245	greg	2.25	int i, j;
246	greg	1.3	/* get/check arguments */
247			fa = getface(ob);
248			if (fa->area == 0.0) {
249			freeface(ob);
250	greg	2.19	return(my_default(ob, il, nm));
251	greg	1.3	}
252			/* set up sampling */
253	greg	2.38	if (il->sampdens <= 0) {
254			nalt = nazi = 1; /* diffuse assumption */
255	greg	2.22	} else {
256	greg	2.38	n = PI * il->sampdens;
257			nalt = sqrt(n/PI) + .5;
258			nazi = PI*nalt + .5;
259	greg	2.22	}
260	greg	2.38	n = nazi*nalt;
261	greg	2.18	newdist(n);
262	greg	2.20	/* take first edge >= sqrt(area) */
263	greg	2.4	for (j = fa->nv-1, i = 0; i < fa->nv; j = i++) {
264			u[0] = VERTEX(fa,i)[0] - VERTEX(fa,j)[0];
265			u[1] = VERTEX(fa,i)[1] - VERTEX(fa,j)[1];
266			u[2] = VERTEX(fa,i)[2] - VERTEX(fa,j)[2];
267	greg	2.5	if ((r1 = DOT(u,u)) >= fa->area-FTINY)
268	greg	2.3	break;
269			}
270			if (i < fa->nv) { /* got one! -- let's align our axes */
271	greg	2.5	r2 = 1.0/sqrt(r1);
272			u[0] = r2; u[1] = r2; u[2] *= r2;
273	greg	2.3	fcross(v, fa->norm, u);
274			} else /* oh well, we'll just have to wing it */
275			mkaxes(u, v, fa->norm);
276			/* now, find limits in (u,v) coordinates */
277	greg	1.3	ur[0] = vr[0] = FHUGE;
278			ur[1] = vr[1] = -FHUGE;
279			for (i = 0; i < fa->nv; i++) {
280			r1 = DOT(VERTEX(fa,i),u);
281			if (r1 < ur[0]) ur[0] = r1;
282			if (r1 > ur[1]) ur[1] = r1;
283			r2 = DOT(VERTEX(fa,i),v);
284			if (r2 < vr[0]) vr[0] = r2;
285			if (r2 > vr[1]) vr[1] = r2;
286			}
287			dim[0] = random();
288			/* sample polygon */
289	greg	2.25	nallow = 5nil->nsamps;
290	greg	2.41	epsilon = .005*sqrt(fa->area);
291	greg	2.21	for (dim[1] = 0; dim[1] < n; dim[1]++)
292	greg	1.3	for (i = 0; i < il->nsamps; i++) {
293	greg	2.23	/* randomize direction */
294	greg	2.21	h = ilhash(dim, 2) + i;
295	greg	2.38	multisamp(sp, 2, urand(h));
296			alti = dim[1]/nazi;
297			r1 = (alti + sp[0])/nalt;
298			r2 = (dim[1] - alti*nazi + sp[1] - .5)/nazi;
299			flatdir(dn, r1, r2);
300			for (j = 0; j < 3; j++)
301	greg	2.21	dir[j] = -dn[0]u[j] - dn[1]v[j] -
302			dn[2]*fa->norm[j];
303	greg	2.23	/* randomize location */
304	greg	1.3	do {
305	greg	2.25	multisamp(sp, 2, urand(h+4862+nallow));
306	greg	1.10	r1 = ur[0] + (ur[1]-ur[0]) * sp[0];
307			r2 = vr[0] + (vr[1]-vr[0]) * sp[1];
308	greg	1.3	for (j = 0; j < 3; j++)
309			org[j] = r1u[j] + r2v[j]
310			+ fa->offset*fa->norm[j];
311	greg	2.25	} while (!inface(org, fa) && nallow-- > 0);
312			if (nallow < 0) {
313	greg	1.3	objerror(ob, WARNING, "bad aspect");
314	greg	2.18	rayclean();
315	greg	1.3	freeface(ob);
316	greg	2.19	return(my_default(ob, il, nm));
317	greg	1.3	}
318	greg	2.41	VSUM(org, org, dir, -epsilon);
319	greg	1.3	/* send sample */
320	greg	2.21	raysamp(dim[1], org, dir);
321	greg	1.3	}
322	greg	2.25	/* add in direct component? */
323	greg	2.38	if (il->flags & IL_LIGHT) {
324	greg	2.25	MAT4 ixfm;
325	greg	2.38	for (i = 3; i--; ) {
326			ixfm[i][0] = u[i];
327			ixfm[i][1] = v[i];
328			ixfm[i][2] = fa->norm[i];
329			ixfm[i][3] = 0.;
330	greg	2.29	}
331	greg	2.38	ixfm[3][0] = ixfm[3][1] = ixfm[3][2] = 0.;
332			ixfm[3][3] = 1.;
333	greg	2.25	dim[0] = random();
334			nallow = 10*il->nsamps;
335			for (i = 0; i < il->nsamps; i++) {
336			/* randomize location */
337			h = dim[0] + samplendx++;
338			do {
339			multisamp(sp, 2, urand(h+nallow));
340			r1 = ur[0] + (ur[1]-ur[0]) * sp[0];
341			r2 = vr[0] + (vr[1]-vr[0]) * sp[1];
342			for (j = 0; j < 3; j++)
343			org[j] = r1u[j] + r2v[j]
344			+ fa->offset*fa->norm[j];
345			} while (!inface(org, fa) && nallow-- > 0);
346			if (nallow < 0) {
347			objerror(ob, WARNING, "bad aspect");
348			rayclean();
349			freeface(ob);
350			return(my_default(ob, il, nm));
351			}
352			/* sample source rays */
353	greg	2.41	srcsamps(il, org, epsilon, ixfm);
354	greg	2.25	}
355			}
356			/* wait for all rays to finish */
357	greg	2.18	rayclean();
358	greg	1.11	/* write out the face and its distribution */
359	greg	2.21	if (average(il, distarr, n)) {
360	greg	1.12	if (il->sampdens > 0)
361			flatout(il, distarr, nalt, nazi, u, v, fa->norm);
362			illumout(il, ob);
363	greg	2.2	} else
364	greg	1.12	printobj(il->altmat, ob);
365	greg	1.3	/* clean up */
366			freeface(ob);
367	greg	2.15	return(0);
368	greg	1.2	}
369
370
371	greg	2.13	int
372	greg	2.18	my_sphere( /* make an illum sphere */
373	greg	2.39	OBJREC *ob,
374	schorsch	2.12	struct illum_args *il,
375			char *nm
376			)
377	greg	1.2	{
378	greg	1.10	int dim[3];
379	greg	1.2	int n, nalt, nazi;
380	greg	1.10	double sp[4], r1, r2, r3;
381	greg	1.4	FVECT org, dir;
382	greg	1.2	FVECT u, v;
383	greg	2.39	int i, j;
384	greg	1.2	/* check arguments */
385			if (ob->oargs.nfargs != 4)
386			objerror(ob, USER, "bad # of arguments");
387			/* set up sampling */
388	greg	1.11	if (il->sampdens <= 0)
389			nalt = nazi = 1;
390			else {
391			n = 4.PI il->sampdens;
392	greg	2.7	nalt = sqrt(2./PI*n) + .5;
393			nazi = PI/2.*nalt + .5;
394	greg	1.11	}
395	greg	1.2	n = nalt*nazi;
396	greg	2.18	newdist(n);
397	greg	1.2	dim[0] = random();
398			/* sample sphere */
399			for (dim[1] = 0; dim[1] < nalt; dim[1]++)
400	greg	1.8	for (dim[2] = 0; dim[2] < nazi; dim[2]++)
401	greg	1.2	for (i = 0; i < il->nsamps; i++) {
402	greg	1.10	/* next sample point */
403	greg	1.11	multisamp(sp, 4, urand(ilhash(dim,3)+i));
404	greg	1.2	/* random direction */
405	greg	1.10	r1 = (dim[1] + sp[0])/nalt;
406	greg	1.13	r2 = (dim[2] + sp[1] - .5)/nazi;
407	greg	1.2	rounddir(dir, r1, r2);
408			/* random location */
409	greg	1.8	mkaxes(u, v, dir); /* yuck! */
410	greg	1.10	r3 = sqrt(sp[2]);
411			r2 = 2.PIsp[3];
412	greg	1.5	r1 = r3ob->oargs.farg[3]cos(r2);
413			r2 = r3ob->oargs.farg[3]sin(r2);
414			r3 = ob->oargs.farg[3]sqrt(1.01-r3r3);
415			for (j = 0; j < 3; j++) {
416			org[j] = ob->oargs.farg[j] + r1u[j] + r2v[j] +
417			r3*dir[j];
418			dir[j] = -dir[j];
419			}
420	greg	1.2	/* send sample */
421	greg	2.18	raysamp(dim[1]*nazi+dim[2], org, dir);
422	greg	1.2	}
423	greg	2.25	/* wait for all rays to finish */
424	greg	2.18	rayclean();
425	greg	1.11	/* write out the sphere and its distribution */
426	greg	2.21	if (average(il, distarr, n)) {
427	greg	1.12	if (il->sampdens > 0)
428			roundout(il, distarr, nalt, nazi);
429			else
430			objerror(ob, WARNING, "diffuse distribution");
431			illumout(il, ob);
432	greg	2.2	} else
433	greg	1.12	printobj(il->altmat, ob);
434	greg	1.2	/* clean up */
435	greg	2.13	return(1);
436	greg	1.2	}
437
438
439	greg	2.13	int
440	greg	2.18	my_ring( /* make an illum ring */
441	schorsch	2.12	OBJREC *ob,
442			struct illum_args *il,
443			char *nm
444			)
445	greg	1.2	{
446	greg	2.21	int dim[2];
447			int n, nalt, nazi, alti;
448			double sp[2], r1, r2, r3;
449			int h;
450	greg	1.4	FVECT dn, org, dir;
451	greg	1.3	FVECT u, v;
452	greg	2.21	MAT4 xfm;
453			CONE *co;
454	greg	2.25	int i, j;
455	greg	1.3	/* get/check arguments */
456			co = getcone(ob, 0);
457			/* set up sampling */
458	greg	2.38	if (il->sampdens <= 0) {
459			nalt = nazi = 1; /* diffuse assumption */
460	greg	2.22	} else {
461	greg	2.38	n = PI * il->sampdens;
462			nalt = sqrt(n/PI) + .5;
463			nazi = PI*nalt + .5;
464	greg	2.22	}
465	greg	2.38	n = nazi*nalt;
466	greg	2.18	newdist(n);
467	greg	1.3	mkaxes(u, v, co->ad);
468			dim[0] = random();
469			/* sample disk */
470	greg	2.21	for (dim[1] = 0; dim[1] < n; dim[1]++)
471	greg	1.3	for (i = 0; i < il->nsamps; i++) {
472	greg	1.10	/* next sample point */
473	greg	2.21	h = ilhash(dim,2) + i;
474	greg	2.23	/* randomize direction */
475	greg	2.38	multisamp(sp, 2, urand(h));
476			alti = dim[1]/nazi;
477			r1 = (alti + sp[0])/nalt;
478			r2 = (dim[1] - alti*nazi + sp[1] - .5)/nazi;
479			flatdir(dn, r1, r2);
480			for (j = 0; j < 3; j++)
481			dir[j] = -dn[0]u[j] - dn[1]v[j] - dn[2]*co->ad[j];
482	greg	2.23	/* randomize location */
483	greg	2.21	multisamp(sp, 2, urand(h+8371));
484	greg	1.5	r3 = sqrt(CO_R0(co)*CO_R0(co) +
485	greg	2.21	sp[0](CO_R1(co)CO_R1(co) - CO_R0(co)*CO_R0(co)));
486			r2 = 2.PIsp[1];
487	greg	1.5	r1 = r3*cos(r2);
488			r2 = r3*sin(r2);
489	greg	2.38	r3 = 5.*FTINY;
490	greg	1.3	for (j = 0; j < 3; j++)
491	greg	2.6	org[j] = CO_P0(co)[j] + r1u[j] + r2v[j] +
492	greg	2.21	r3*co->ad[j];
493	greg	1.3	/* send sample */
494	greg	2.21	raysamp(dim[1], org, dir);
495	greg	1.3	}
496	greg	2.25	/* add in direct component? */
497	greg	2.38	if (il->flags & IL_LIGHT) {
498	greg	2.25	MAT4 ixfm;
499	greg	2.38	for (i = 3; i--; ) {
500			ixfm[i][0] = u[i];
501			ixfm[i][1] = v[i];
502			ixfm[i][2] = co->ad[i];
503			ixfm[i][3] = 0.;
504	greg	2.29	}
505	greg	2.38	ixfm[3][0] = ixfm[3][1] = ixfm[3][2] = 0.;
506			ixfm[3][3] = 1.;
507	greg	2.25	dim[0] = random();
508			for (i = 0; i < il->nsamps; i++) {
509			/* randomize location */
510			h = dim[0] + samplendx++;
511			multisamp(sp, 2, urand(h));
512			r3 = sqrt(CO_R0(co)*CO_R0(co) +
513			sp[0](CO_R1(co)CO_R1(co) - CO_R0(co)*CO_R0(co)));
514			r2 = 2.PIsp[1];
515			r1 = r3*cos(r2);
516			r2 = r3*sin(r2);
517			for (j = 0; j < 3; j++)
518			org[j] = CO_P0(co)[j] + r1u[j] + r2v[j];
519			/* sample source rays */
520	greg	2.41	srcsamps(il, org, 5.*FTINY, ixfm);
521	greg	2.25	}
522			}
523			/* wait for all rays to finish */
524	greg	2.18	rayclean();
525	greg	1.11	/* write out the ring and its distribution */
526	greg	2.21	if (average(il, distarr, n)) {
527	greg	1.12	if (il->sampdens > 0)
528			flatout(il, distarr, nalt, nazi, u, v, co->ad);
529			illumout(il, ob);
530	greg	2.2	} else
531	greg	1.12	printobj(il->altmat, ob);
532	greg	1.3	/* clean up */
533			freecone(ob);
534	greg	2.13	return(1);
535	greg	1.2	}