src/gen/mkillum2.c

#ifndef lint
static const char       RCSid[] = "$Id: mkillum2.c,v 2.21 2007/09/21 05:53:21 greg Exp $";
#endif
/*
 * Routines to do the actual calculation for mkillum
 */

#include <string.h>

#include  "mkillum.h"
#include  "face.h"
#include  "cone.h"
#include  "random.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(RAY *r, int rv)
{
        COLORV  *colp;

        if (rv == 0)
                return(0);
        if (rv < 0)
                error(USER, "ray tracing process died");
        if (r->rno >= distsiz)
                error(INTERNAL, "bad returned index in process_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
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);
}


static void
flatdir(                /* compute uniform hemispherical direction */
        register 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
)
{
#define MAXMISS         (5*n*il->nsamps)
        int  dim[2];
        int  n, nalt, nazi, h, alti;
        double  sp[2], r1, r2;
        FVECT  dn, org, dir;
        FVECT  u, v;
        double  ur[2], vr[2];
        MAT4  xfm;
        int  nmisses;
        FACE  *fa;
        register 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 */
        nmisses = 0;
        for (dim[1] = 0; dim[1] < n; dim[1]++)
                for (i = 0; i < il->nsamps; i++) {
                                        /* random 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];
                    }
                                        /* random location */
                    do {
                        multisamp(sp, 2, urand(h+4862+nmisses));
                        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) && nmisses++ < MAXMISS);
                    if (nmisses > MAXMISS) {
                        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 - .0001;
                    else
                        r1 = .0001;
                    for (j = 0; j < 3; j++)
                        org[j] += r1*fa->norm[j];
                                        /* send sample */
                    raysamp(dim[1], org, dir);
                }
        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);
#undef MAXMISS
}


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);
                }
        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;
        register 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;
                                        /* random 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];
                    }
                                        /* random 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 - .0001;
                    else
                        r3 = .0001;
                    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);
                }
        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:	2.22
Committed:	Sun Sep 30 19:05:26 2007 UTC (18 years, 1 month ago) by greg
Content type:	text/plain
Branch:	MAIN
Changes since 2.21:	+27 -19 lines
Log Message:	Fixed BTDF sampling density to match output angles
#	User	Rev	Content
1	greg	1.1	#ifndef lint
2	greg	2.22	static const char RCSid[] = "$Id: mkillum2.c,v 2.21 2007/09/21 05:53:21 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	1.2	#include "random.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			if (siz == 0) {
26			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	2.18	process_ray(RAY *r, int rv)
46			{
47			COLORV *colp;
48
49			if (rv == 0)
50			return(0);
51			if (rv < 0)
52	greg	2.20	error(USER, "ray tracing process died");
53	greg	2.18	if (r->rno >= distsiz)
54	greg	2.20	error(INTERNAL, "bad returned index in process_ray");
55	greg	2.18	colp = &distarr[r->rno * 3];
56			addcolor(colp, r->rcol);
57			return(1);
58			}
59
60
61	greg	2.21	void
62	greg	2.18	raysamp( /* queue a ray sample */
63			int ndx,
64			FVECT org,
65			FVECT dir
66	greg	2.16	)
67			{
68	greg	2.18	RAY myRay;
69			int rv;
70
71			if ((ndx < 0) \| (ndx >= distsiz))
72	greg	2.20	error(INTERNAL, "bad index in raysamp");
73	greg	2.18	VCOPY(myRay.rorg, org);
74			VCOPY(myRay.rdir, dir);
75			myRay.rmax = .0;
76			rayorigin(&myRay, PRIMARY, NULL, NULL);
77			myRay.rno = ndx;
78			/* queue ray, check result */
79			process_ray(&myRay, ray_pqueue(&myRay));
80			}
81
82
83	greg	2.21	void
84	greg	2.18	rayclean() /* finish all pending rays */
85			{
86			RAY myRay;
87
88			while (process_ray(&myRay, ray_presult(&myRay, 0)))
89	greg	2.16	;
90			}
91	schorsch	2.12
92
93	greg	2.21	static void
94			mkaxes( /* compute u and v to go with n */
95			FVECT u,
96			FVECT v,
97			FVECT n
98			)
99			{
100			register int i;
101
102			v[0] = v[1] = v[2] = 0.0;
103			for (i = 0; i < 3; i++)
104			if (n[i] < 0.6 && n[i] > -0.6)
105			break;
106			v[i] = 1.0;
107			fcross(u, v, n);
108			normalize(u);
109			fcross(v, n, u);
110			}
111
112
113			static void
114			rounddir( /* compute uniform spherical direction */
115			register FVECT dv,
116			double alt,
117			double azi
118			)
119			{
120			double d1, d2;
121
122			dv[2] = 1. - 2.*alt;
123			d1 = sqrt(1. - dv[2]*dv[2]);
124			d2 = 2.PI azi;
125			dv[0] = d1*cos(d2);
126			dv[1] = d1*sin(d2);
127			}
128
129
130			static void
131			flatdir( /* compute uniform hemispherical direction */
132			register FVECT dv,
133			double alt,
134			double azi
135			)
136			{
137			double d1, d2;
138
139			d1 = sqrt(alt);
140			d2 = 2.PI azi;
141			dv[0] = d1*cos(d2);
142			dv[1] = d1*sin(d2);
143			dv[2] = sqrt(1. - alt);
144			}
145
146
147	greg	2.19	int
148	greg	2.18	my_default( /* default illum action */
149	schorsch	2.12	OBJREC *ob,
150			struct illum_args *il,
151			char *nm
152			)
153	greg	1.1	{
154	greg	1.2	sprintf(errmsg, "(%s): cannot make illum for %s \"%s\"",
155			nm, ofun[ob->otype].funame, ob->oname);
156			error(WARNING, errmsg);
157	greg	2.2	printobj(il->altmat, ob);
158	greg	2.13	return(1);
159	greg	1.2	}
160
161
162	greg	2.13	int
163	greg	2.18	my_face( /* make an illum face */
164	schorsch	2.12	OBJREC *ob,
165			struct illum_args *il,
166			char *nm
167			)
168	greg	1.2	{
169	greg	1.3	#define MAXMISS (5nil->nsamps)
170	greg	2.21	int dim[2];
171			int n, nalt, nazi, h, alti;
172	greg	1.10	double sp[2], r1, r2;
173	greg	1.4	FVECT dn, org, dir;
174	greg	1.3	FVECT u, v;
175			double ur[2], vr[2];
176	greg	2.21	MAT4 xfm;
177	greg	1.3	int nmisses;
178	greg	2.21	FACE *fa;
179	greg	1.3	register int i, j;
180			/* get/check arguments */
181			fa = getface(ob);
182			if (fa->area == 0.0) {
183			freeface(ob);
184	greg	2.19	return(my_default(ob, il, nm));
185	greg	1.3	}
186			/* set up sampling */
187	greg	2.21	if (il->sd != NULL) {
188			if (!getBSDF_xfm(xfm, fa->norm, il->udir)) {
189			objerror(ob, WARNING, "illegal up direction");
190			freeface(ob);
191			return(my_default(ob, il, nm));
192			}
193			n = il->sd->ninc;
194	greg	2.22	} else {
195			if (il->sampdens <= 0) {
196			nalt = nazi = 1; /* diffuse assumption */
197			} else {
198			n = PI * il->sampdens;
199			nalt = sqrt(n/PI) + .5;
200			nazi = PI*nalt + .5;
201			}
202	greg	2.21	n = nazi*nalt;
203	greg	2.22	}
204	greg	2.18	newdist(n);
205	greg	2.20	/* take first edge >= sqrt(area) */
206	greg	2.4	for (j = fa->nv-1, i = 0; i < fa->nv; j = i++) {
207			u[0] = VERTEX(fa,i)[0] - VERTEX(fa,j)[0];
208			u[1] = VERTEX(fa,i)[1] - VERTEX(fa,j)[1];
209			u[2] = VERTEX(fa,i)[2] - VERTEX(fa,j)[2];
210	greg	2.5	if ((r1 = DOT(u,u)) >= fa->area-FTINY)
211	greg	2.3	break;
212			}
213			if (i < fa->nv) { /* got one! -- let's align our axes */
214	greg	2.5	r2 = 1.0/sqrt(r1);
215			u[0] = r2; u[1] = r2; u[2] *= r2;
216	greg	2.3	fcross(v, fa->norm, u);
217			} else /* oh well, we'll just have to wing it */
218			mkaxes(u, v, fa->norm);
219			/* now, find limits in (u,v) coordinates */
220	greg	1.3	ur[0] = vr[0] = FHUGE;
221			ur[1] = vr[1] = -FHUGE;
222			for (i = 0; i < fa->nv; i++) {
223			r1 = DOT(VERTEX(fa,i),u);
224			if (r1 < ur[0]) ur[0] = r1;
225			if (r1 > ur[1]) ur[1] = r1;
226			r2 = DOT(VERTEX(fa,i),v);
227			if (r2 < vr[0]) vr[0] = r2;
228			if (r2 > vr[1]) vr[1] = r2;
229			}
230			dim[0] = random();
231			/* sample polygon */
232			nmisses = 0;
233	greg	2.21	for (dim[1] = 0; dim[1] < n; dim[1]++)
234	greg	1.3	for (i = 0; i < il->nsamps; i++) {
235			/* random direction */
236	greg	2.21	h = ilhash(dim, 2) + i;
237			if (il->sd != NULL) {
238			r_BSDF_incvec(dir, il->sd, dim[1], urand(h), xfm);
239			} else {
240			multisamp(sp, 2, urand(h));
241			alti = dim[1]/nazi;
242			r1 = (alti + sp[0])/nalt;
243			r2 = (dim[1] - alti*nazi + sp[1] - .5)/nazi;
244			flatdir(dn, r1, r2);
245			for (j = 0; j < 3; j++)
246			dir[j] = -dn[0]u[j] - dn[1]v[j] -
247			dn[2]*fa->norm[j];
248			}
249	greg	1.3	/* random location */
250			do {
251	greg	1.11	multisamp(sp, 2, urand(h+4862+nmisses));
252	greg	1.10	r1 = ur[0] + (ur[1]-ur[0]) * sp[0];
253			r2 = vr[0] + (vr[1]-vr[0]) * sp[1];
254	greg	1.3	for (j = 0; j < 3; j++)
255			org[j] = r1u[j] + r2v[j]
256			+ fa->offset*fa->norm[j];
257			} while (!inface(org, fa) && nmisses++ < MAXMISS);
258			if (nmisses > MAXMISS) {
259			objerror(ob, WARNING, "bad aspect");
260	greg	2.18	rayclean();
261	greg	1.3	freeface(ob);
262	greg	2.19	return(my_default(ob, il, nm));
263	greg	1.3	}
264	greg	2.21	if (il->sd != NULL && DOT(dir, fa->norm) < -FTINY)
265			r1 = -1.0001*il->thick - .0001;
266			else
267			r1 = .0001;
268	greg	1.3	for (j = 0; j < 3; j++)
269	greg	2.21	org[j] += r1*fa->norm[j];
270	greg	1.3	/* send sample */
271	greg	2.21	raysamp(dim[1], org, dir);
272	greg	1.3	}
273	greg	2.18	rayclean();
274	greg	2.22	if (il->sd != NULL) { /* run distribution through BSDF */
275			nalt = sqrt(il->sd->nout/PI) + .5;
276			nazi = PI*nalt + .5;
277	greg	2.21	redistribute(il->sd, nalt, nazi, u, v, fa->norm, xfm);
278	greg	2.22	}
279	greg	1.11	/* write out the face and its distribution */
280	greg	2.21	if (average(il, distarr, n)) {
281	greg	1.12	if (il->sampdens > 0)
282			flatout(il, distarr, nalt, nazi, u, v, fa->norm);
283			illumout(il, ob);
284	greg	2.2	} else
285	greg	1.12	printobj(il->altmat, ob);
286	greg	1.3	/* clean up */
287			freeface(ob);
288	greg	2.15	return(0);
289	greg	1.3	#undef MAXMISS
290	greg	1.2	}
291
292
293	greg	2.13	int
294	greg	2.18	my_sphere( /* make an illum sphere */
295	schorsch	2.12	register OBJREC *ob,
296			struct illum_args *il,
297			char *nm
298			)
299	greg	1.2	{
300	greg	1.10	int dim[3];
301	greg	1.2	int n, nalt, nazi;
302	greg	1.10	double sp[4], r1, r2, r3;
303	greg	1.4	FVECT org, dir;
304	greg	1.2	FVECT u, v;
305			register int i, j;
306			/* check arguments */
307			if (ob->oargs.nfargs != 4)
308			objerror(ob, USER, "bad # of arguments");
309			/* set up sampling */
310	greg	1.11	if (il->sampdens <= 0)
311			nalt = nazi = 1;
312			else {
313			n = 4.PI il->sampdens;
314	greg	2.7	nalt = sqrt(2./PI*n) + .5;
315			nazi = PI/2.*nalt + .5;
316	greg	1.11	}
317	greg	2.21	if (il->sd != NULL)
318			objerror(ob, WARNING, "BSDF ignored");
319	greg	1.2	n = nalt*nazi;
320	greg	2.18	newdist(n);
321	greg	1.2	dim[0] = random();
322			/* sample sphere */
323			for (dim[1] = 0; dim[1] < nalt; dim[1]++)
324	greg	1.8	for (dim[2] = 0; dim[2] < nazi; dim[2]++)
325	greg	1.2	for (i = 0; i < il->nsamps; i++) {
326	greg	1.10	/* next sample point */
327	greg	1.11	multisamp(sp, 4, urand(ilhash(dim,3)+i));
328	greg	1.2	/* random direction */
329	greg	1.10	r1 = (dim[1] + sp[0])/nalt;
330	greg	1.13	r2 = (dim[2] + sp[1] - .5)/nazi;
331	greg	1.2	rounddir(dir, r1, r2);
332			/* random location */
333	greg	1.8	mkaxes(u, v, dir); /* yuck! */
334	greg	1.10	r3 = sqrt(sp[2]);
335			r2 = 2.PIsp[3];
336	greg	1.5	r1 = r3ob->oargs.farg[3]cos(r2);
337			r2 = r3ob->oargs.farg[3]sin(r2);
338			r3 = ob->oargs.farg[3]sqrt(1.01-r3r3);
339			for (j = 0; j < 3; j++) {
340			org[j] = ob->oargs.farg[j] + r1u[j] + r2v[j] +
341			r3*dir[j];
342			dir[j] = -dir[j];
343			}
344	greg	1.2	/* send sample */
345	greg	2.18	raysamp(dim[1]*nazi+dim[2], org, dir);
346	greg	1.2	}
347	greg	2.18	rayclean();
348	greg	1.11	/* write out the sphere and its distribution */
349	greg	2.21	if (average(il, distarr, n)) {
350	greg	1.12	if (il->sampdens > 0)
351			roundout(il, distarr, nalt, nazi);
352			else
353			objerror(ob, WARNING, "diffuse distribution");
354			illumout(il, ob);
355	greg	2.2	} else
356	greg	1.12	printobj(il->altmat, ob);
357	greg	1.2	/* clean up */
358	greg	2.13	return(1);
359	greg	1.2	}
360
361
362	greg	2.13	int
363	greg	2.18	my_ring( /* make an illum ring */
364	schorsch	2.12	OBJREC *ob,
365			struct illum_args *il,
366			char *nm
367			)
368	greg	1.2	{
369	greg	2.21	int dim[2];
370			int n, nalt, nazi, alti;
371			double sp[2], r1, r2, r3;
372			int h;
373	greg	1.4	FVECT dn, org, dir;
374	greg	1.3	FVECT u, v;
375	greg	2.21	MAT4 xfm;
376			CONE *co;
377	greg	1.3	register int i, j;
378			/* get/check arguments */
379			co = getcone(ob, 0);
380			/* set up sampling */
381	greg	2.21	if (il->sd != NULL) {
382			if (!getBSDF_xfm(xfm, co->ad, il->udir)) {
383			objerror(ob, WARNING, "illegal up direction");
384			freecone(ob);
385			return(my_default(ob, il, nm));
386			}
387			n = il->sd->ninc;
388	greg	2.22	} else {
389			if (il->sampdens <= 0) {
390			nalt = nazi = 1; /* diffuse assumption */
391			} else {
392			n = PI * il->sampdens;
393			nalt = sqrt(n/PI) + .5;
394			nazi = PI*nalt + .5;
395			}
396	greg	2.21	n = nazi*nalt;
397	greg	2.22	}
398	greg	2.18	newdist(n);
399	greg	1.3	mkaxes(u, v, co->ad);
400			dim[0] = random();
401			/* sample disk */
402	greg	2.21	for (dim[1] = 0; dim[1] < n; dim[1]++)
403	greg	1.3	for (i = 0; i < il->nsamps; i++) {
404	greg	1.10	/* next sample point */
405	greg	2.21	h = ilhash(dim,2) + i;
406	greg	1.3	/* random direction */
407	greg	2.21	if (il->sd != NULL) {
408			r_BSDF_incvec(dir, il->sd, dim[1], urand(h), xfm);
409			} else {
410			multisamp(sp, 2, urand(h));
411			alti = dim[1]/nazi;
412			r1 = (alti + sp[0])/nalt;
413			r2 = (dim[1] - alti*nazi + sp[1] - .5)/nazi;
414			flatdir(dn, r1, r2);
415			for (j = 0; j < 3; j++)
416	greg	1.5	dir[j] = -dn[0]u[j] - dn[1]v[j] - dn[2]*co->ad[j];
417	greg	2.21	}
418	greg	1.3	/* random location */
419	greg	2.21	multisamp(sp, 2, urand(h+8371));
420	greg	1.5	r3 = sqrt(CO_R0(co)*CO_R0(co) +
421	greg	2.21	sp[0](CO_R1(co)CO_R1(co) - CO_R0(co)*CO_R0(co)));
422			r2 = 2.PIsp[1];
423	greg	1.5	r1 = r3*cos(r2);
424			r2 = r3*sin(r2);
425	greg	2.21	if (il->sd != NULL && DOT(dir, co->ad) < -FTINY)
426			r3 = -1.0001*il->thick - .0001;
427			else
428			r3 = .0001;
429	greg	1.3	for (j = 0; j < 3; j++)
430	greg	2.6	org[j] = CO_P0(co)[j] + r1u[j] + r2v[j] +
431	greg	2.21	r3*co->ad[j];
432	greg	1.3	/* send sample */
433	greg	2.21	raysamp(dim[1], org, dir);
434	greg	1.3	}
435	greg	2.18	rayclean();
436	greg	2.22	if (il->sd != NULL) { /* run distribution through BSDF */
437			nalt = sqrt(il->sd->nout/PI) + .5;
438			nazi = PI*nalt + .5;
439	greg	2.21	redistribute(il->sd, nalt, nazi, u, v, co->ad, xfm);
440	greg	2.22	}
441	greg	1.11	/* write out the ring and its distribution */
442	greg	2.21	if (average(il, distarr, n)) {
443	greg	1.12	if (il->sampdens > 0)
444			flatout(il, distarr, nalt, nazi, u, v, co->ad);
445			illumout(il, ob);
446	greg	2.2	} else
447	greg	1.12	printobj(il->altmat, ob);
448	greg	1.3	/* clean up */
449			freecone(ob);
450	greg	2.13	return(1);
451	greg	1.2	}