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root/radiance/src/gen/genbranch.c
Revision: 2.5
Committed: Sat Feb 22 02:07:23 2003 UTC (22 years, 8 months ago) by greg
Content type: text/plain
Branch: MAIN
CVS Tags: rad3R5
Changes since 2.4: +3 -8 lines
Log Message: 
Changes and check-in for 3.5 release
Includes new source files and modifications not recorded for many years
See ray/doc/notes/ReleaseNotes for notes between 3.1 and 3.5 release

File Contents

# User Rev Content
1 greg 1.1 #ifndef lint
2 greg 2.5 static const char RCSid[] = "$Id$";
3 greg 1.1 #endif
4 greg 1.2 /*
5 greg 1.1 * genbranch.c - program to generate 3D Christmas tree branches.
6     *
7     * 8/23/86
8     */
9    
10     #include <stdio.h>
11    
12 greg 2.5 #include <stdlib.h>
13    
14 greg 2.3 #include <math.h>
15    
16 greg 1.1 #include "random.h"
17    
18     #define errf() (var*(0.5-frandom()))
19 greg 2.2
20 greg 1.1 double bstart[3] = {0.0, 0.0, 0.0}; /* start of branch */
21     double bend[3] = {28.0, 8.0, 0.0}; /* end of branch */
22     double bthick = .6; /* branch radius at base */
23     double bnarrow = .4; /* ratio of tip radius to base */
24     double bratio = .4; /* ratio of limb to branch */
25     char *branchmat = "m_bark"; /* bark material */
26    
27     char *leafmat = "m_leaf"; /* leaf material */
28    
29     int nshoots = 7; /* number of offshoots */
30     int rdepth = 3; /* recursion depth */
31    
32     double var = 0.3; /* variability */
33 greg 2.4
34 greg 1.1
35     main(argc, argv)
36     int argc;
37     char *argv[];
38     {
39     int i, j;
40    
41     for (i = 1; i < argc && argv[i][0] == '-'; i++)
42     switch (argv[i][1]) {
43     case 'b': /* branch */
44     switch (argv[i][2]) {
45     case 's': /* start */
46     bstart[0] = atof(argv[++i]);
47     bstart[1] = atof(argv[++i]);
48     bstart[2] = atof(argv[++i]);
49     break;
50     case 'e': /* end */
51     bend[0] = atof(argv[++i]);
52     bend[1] = atof(argv[++i]);
53     bend[2] = atof(argv[++i]);
54     break;
55     case 't': /* thickness */
56     bthick = atof(argv[++i]);
57     break;
58     case 'n': /* narrow */
59     bnarrow = atof(argv[++i]);
60     break;
61     case 'r': /* ratio */
62     bratio = atof(argv[++i]);
63     break;
64     case 'm': /* material */
65     branchmat = argv[++i];
66     break;
67     default:
68     goto unkopt;
69     }
70     break;
71     case 'l': /* leaf */
72     switch (argv[i][2]) {
73     case 'm': /* material */
74     leafmat = argv[++i];
75     break;
76     default:
77     goto unkopt;
78     }
79     break;
80     case 'n': /* number of offshoots */
81     nshoots = atoi(argv[++i]);
82     break;
83     case 'r': /* recursion depth */
84     rdepth = atoi(argv[++i]);
85     break;
86     case 's': /* seed */
87     j = atoi(argv[++i]);
88     while (j-- > 0)
89     frandom();
90     break;
91     case 'v': /* variability */
92     var = atof(argv[++i]);
93     break;
94     default:;
95     unkopt: fprintf(stderr, "%s: unknown option: %s\n",
96     argv[0], argv[i]);
97     exit(1);
98     }
99    
100     if (i != argc) {
101     fprintf(stderr, "%s: bad argument\n", argv[0]);
102     exit(1);
103     }
104     printhead(argc, argv);
105    
106     branch(bstart, bend, bthick, rdepth);
107    
108     return(0);
109     }
110    
111    
112     branch(beg, end, rad, lvl) /* generate branch recursively */
113     double beg[3], end[3];
114     double rad;
115     int lvl;
116     {
117     double sqrt();
118     double newbeg[3], newend[3];
119     double t;
120     int i, j;
121    
122     if (lvl == 0) {
123     stick(leafmat, beg, end, rad);
124     return;
125     }
126    
127     stick(branchmat, beg, end, rad);
128    
129     for (i = 1; i <= nshoots; i++) {
130     /* right branch */
131     t = (i+errf())/(nshoots+2);
132     t = (t + sqrt(t))/2.0;
133     for (j = 0; j < 3; j++) {
134     newbeg[j] = newend[j] = (end[j]-beg[j])*t + beg[j];
135     newend[j] += (end[j]-beg[j])*(1+errf())/(nshoots+2);
136     }
137     newend[0] += (end[2]-newbeg[2])*bratio*(1+errf());
138     newend[1] += (end[1]-newbeg[1])*bratio*(1+errf());
139     newend[2] -= (end[0]-newbeg[0])*bratio*(1+errf());
140     branch(newbeg, newend,
141     (1-(1-bnarrow)*t)*(1+2*bratio)/3*rad, lvl-1);
142    
143     /* left branch */
144     t = (i+errf())/(nshoots+2);
145     t = (t + sqrt(t))/2.0;
146     for (j = 0; j < 3; j++) {
147     newbeg[j] = newend[j] = (end[j]-beg[j])*t + beg[j];
148     newend[j] += (end[j]-beg[j])*(1+errf())/(nshoots+2);
149     }
150     newend[0] -= (end[2]-newbeg[2])*bratio*(1+errf());
151     newend[1] += (end[1]-newbeg[1])*bratio*(1+errf());
152     newend[2] += (end[0]-newbeg[0])*bratio*(1+errf());
153     branch(newbeg, newend,
154     (1-(1-bnarrow)*t)*(1+2*bratio)/3*rad, lvl-1);
155     }
156     }
157    
158    
159     stick(mat, beg, end, rad) /* output a branch or leaf */
160     char *mat;
161     double beg[3], end[3];
162     double rad;
163     {
164     static int nsticks = 0;
165    
166     printf("\n%s cone s%d\n", mat, nsticks);
167     printf("0\n0\n8\n");
168     printf("\t%18.12g\t%18.12g\t%18.12g\n", beg[0], beg[1], beg[2]);
169     printf("\t%18.12g\t%18.12g\t%18.12g\n", end[0], end[1], end[2]);
170     printf("\t%18.12g\t%18.12g\n", rad, bnarrow*rad);
171    
172     printf("\n%s sphere e%d\n", mat, nsticks);
173     printf("0\n0\n4");
174     printf("\t%18.12g\t%18.12g\t%18.12g\%18.12g\n",
175     end[0], end[1], end[2], bnarrow*rad);
176    
177     nsticks++;
178     }
179    
180    
181     printhead(ac, av) /* print command header */
182     register int ac;
183     register char **av;
184     {
185     putchar('#');
186     while (ac--) {
187     putchar(' ');
188     fputs(*av++, stdout);
189     }
190     putchar('\n');
191     }