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root/radiance/ray/src/rt/m_mirror.c
Revision: 2.12
Committed: Sat Jun 6 02:11:43 2009 UTC (14 years, 9 months ago) by greg
Content type: text/plain
Branch: MAIN
CVS Tags: rad4R0
Changes since 2.11: +18 -11 lines
Log Message:
Fixed erroneous "aiming failure" with certain mirrored virtual sources

File Contents

# Content
1 #ifndef lint
2 static const char RCSid[] = "$Id: m_mirror.c,v 2.11 2005/04/19 01:15:06 greg Exp $";
3 #endif
4 /*
5 * Routines for mirror material supporting virtual light sources
6 */
7
8 #include "copyright.h"
9
10 #include "ray.h"
11 #include "otypes.h"
12 #include "rtotypes.h"
13 #include "source.h"
14
15 /*
16 * The real arguments for MAT_MIRROR are simply:
17 *
18 * 3 rrefl grefl brefl
19 *
20 * Additionally, the user may specify a single string argument
21 * which is interpreted as the name of the material to use
22 * instead of the mirror if the ray being considered is not
23 * part of the direct calculation.
24 */
25
26 static int mir_proj(MAT4 pm, OBJREC *o, SRCREC *s, int n);
27 static void mirrorproj(MAT4 m, FVECT nv, double offs);
28
29 VSMATERIAL mirror_vs = {mir_proj, 1};
30
31
32 extern int
33 m_mirror( /* shade mirrored ray */
34 register OBJREC *m,
35 register RAY *r
36 )
37 {
38 COLOR mcolor;
39 RAY nr;
40 int rpure = 1;
41 register int i;
42 /* check arguments */
43 if (m->oargs.nfargs != 3 || m->oargs.nsargs > 1)
44 objerror(m, USER, "bad number of arguments");
45 /* check for substitute material */
46 if (m->oargs.nsargs > 0 &&
47 (r->rsrc < 0 || source[r->rsrc].so != r->ro)) {
48 if (!strcmp(m->oargs.sarg[0], VOIDID)) {
49 raytrans(r);
50 return(1);
51 }
52 return(rayshade(r, lastmod(objndx(m), m->oargs.sarg[0])));
53 }
54 /* check for bad source ray */
55 if (r->rsrc >= 0 && source[r->rsrc].so != r->ro)
56 return(1);
57
58 if (r->rod < 0.) /* back is black */
59 return(1);
60 /* get modifiers */
61 raytexture(r, m->omod);
62 /* assign material color */
63 setcolor(mcolor, m->oargs.farg[0],
64 m->oargs.farg[1],
65 m->oargs.farg[2]);
66 multcolor(mcolor, r->pcol);
67 /* compute reflected ray */
68 if (r->rsrc >= 0) { /* relayed light source */
69 rayorigin(&nr, REFLECTED, r, mcolor);
70 /* ignore textures */
71 for (i = 0; i < 3; i++)
72 nr.rdir[i] = r->rdir[i] + 2.*r->rod*r->ron[i];
73 /* source we're aiming for next */
74 nr.rsrc = source[r->rsrc].sa.sv.sn;
75 } else { /* ordinary reflection */
76 FVECT pnorm;
77 double pdot;
78
79 if (rayorigin(&nr, REFLECTED, r, mcolor) < 0)
80 return(1);
81 if (DOT(r->pert,r->pert) > FTINY*FTINY) {
82 pdot = raynormal(pnorm, r); /* use textures */
83 for (i = 0; i < 3; i++)
84 nr.rdir[i] = r->rdir[i] + 2.*pdot*pnorm[i];
85 rpure = 0;
86 }
87 /* check for penetration */
88 if (rpure || DOT(nr.rdir, r->ron) <= FTINY)
89 for (i = 0; i < 3; i++)
90 nr.rdir[i] = r->rdir[i] + 2.*r->rod*r->ron[i];
91 }
92 rayvalue(&nr);
93 multcolor(nr.rcol, nr.rcoef);
94 addcolor(r->rcol, nr.rcol);
95 if (rpure && r->ro != NULL && isflat(r->ro->otype))
96 r->rt = r->rot + nr.rt;
97 return(1);
98 }
99
100
101 static int
102 mir_proj( /* compute a mirror's projection */
103 MAT4 pm,
104 register OBJREC *o,
105 SRCREC *s,
106 int n
107 )
108 {
109 double corr = 1.;
110 FVECT nv, sc;
111 double od, offs;
112 int i;
113 /* get surface normal and offset */
114 offs = od = getplaneq(nv, o);
115 if (s->sflags & SDISTANT)
116 offs = 0.;
117 /* check for extreme point behind */
118 if (s->sflags & SCIR) {
119 if (s->sflags & (SFLAT|SDISTANT))
120 corr = 1.12837917; /* correct setflatss() */
121 else
122 corr = 1.0/0.7236; /* correct sphsetsrc() */
123 }
124 VCOPY(sc, s->sloc);
125 for (i = s->sflags & SFLAT ? SV : SW; i >= 0; i--)
126 if (DOT(nv, s->ss[i]) > offs)
127 VSUM(sc, sc, s->ss[i], corr);
128 else
129 VSUM(sc, sc, s->ss[i], -corr);
130 if (DOT(sc, nv) <= offs+FTINY)
131 return(0);
132 /* everything OK -- compute projection */
133 mirrorproj(pm, nv, od);
134 return(1);
135 }
136
137
138 static void
139 mirrorproj( /* get mirror projection for surface */
140 register MAT4 m,
141 FVECT nv,
142 double offs
143 )
144 {
145 register int i, j;
146 /* assign matrix */
147 setident4(m);
148 for (j = 0; j < 3; j++) {
149 for (i = 0; i < 3; i++)
150 m[i][j] -= 2.*nv[i]*nv[j];
151 m[3][j] = 2.*offs*nv[j];
152 }
153 }