4 # ./distort-stl <INPUT >OUTPUT DISTORTION [PARAMS...] ...
8 # project-cylinder RADIUS
9 # projects the X-Z plane onto the cylinder of
10 # radius RADIUS with axis [0, 0, t]
11 # origin becomes [0, -RADIUS, 0]
12 # other planes of the input are projected onto smaller
13 # or larger cylinders accordingly
14 # probably a bad idea if
15 # object has any Y > RADIUS
16 # object has any |X| > tau / RADIUS
17 # technically, treats input as if it were
18 # polar-rectangular coords:
19 # Z' = Z; R' = Y + RADIUS; theta' = X / RADIUS
20 # and then converts back into cartesian
21 # honours fa but not fs or fn
33 sub TAU () { M_PI * 2; }
45 #no warnings qw(recursion);
47 sub sprintf_triangle ($) {
51 "%11.6f,%11.6f,%11.6f / ".
52 "%11.6f,%11.6f,%11.6f / ".
53 "%11.6f,%11.6f,%11.6f %-40s ",
54 $t->[0][0], $t->[0][1], $t->[0][2],
55 $t->[1][0], $t->[1][1], $t->[1][2],
56 $t->[2][0], $t->[2][1], $t->[2][2],
60 sub maybe_subdivide_triangle ($$$$) {
61 my ($t, $ok, $changed, $edge_need_subdivide_fn) = @_;
63 print STDERR sprintf_triangle $t;
65 foreach my $ix (0..2) {
68 if ($edge_need_subdivide_fn->($t->[$ix], $t->[$jx])) {
73 foreach my $ci (0..2) {
74 push @midp, 0.5 * ($t->[$ix][$ci] + $t->[$jx][$ci]);
78 " midp %11.6f,%11.6f,%11.6f\n",
81 # triangle i-j-k, splitting edge i-m
83 my $n = [ @$t ]; $n->[$ix] = \@midp; $n->[3] = "$t->[3]a$ix$jx";
84 unshift @$changed, $n;
86 printf STDERR "%s\n", sprintf_triangle $n;
88 my $n = [ @$t ]; $n->[$jx] = \@midp; $n->[3] = "$t->[3]b$ix$jx";
89 unshift @$changed, $n;
91 printf STDERR "%s\n", sprintf_triangle $n;
97 printf STDERR "OK nok=%d nchanged=%d\n",
98 (scalar @$ok), (scalar @$changed);
101 sub maybe_subdivide ($) {
102 my ($edge_need_subdivide_fn) = @_;
104 my @small_enough = ();
105 while (my $t = shift @$triangles) {
106 maybe_subdivide_triangle $t, \@small_enough, $triangles,
107 $edge_need_subdivide_fn;
110 $triangles = \@small_enough;
113 sub append_triangle ($) {
118 #---------- set-fa ----------
124 #---------- project-cylinder ----------
126 our $project_cylinder_radius;
127 our $project_cylinder_max_d_theta;
129 sub project_cylinder_edge_need_subdivide ($$) {
130 my @thetas = map { $_->[0] / $project_cylinder_radius } @_;
131 return abs($thetas[0] - $thetas[1]) > $project_cylinder_max_d_theta;
134 sub project_cylinder_tri {
137 #print STDERR 'PROJECT', Dumper($t);
139 my $radius = $project_cylinder_radius;
142 foreach my $p (@$t) {
144 my $r = $radius - $y;
145 my $theta = $x / $radius;
146 push @ot, [ $r * sin($theta),
150 append_triangle \@ot;
153 sub op__project_cylinder () {
154 $project_cylinder_radius = shift_arg;
155 $project_cylinder_max_d_theta = $fa * TAU/360;
157 maybe_subdivide \&project_cylinder_edge_need_subdivide;
160 foreach my $t (@$triangles) {
161 project_cylinder_tri $t;
163 $triangles = $output;
166 #---------- main program ----------
170 while (@ARGV && $ARGV[0] =~ m/^-/) {
183 my $admesh_stdout = '--write-ascii-stl /dev/fd/3 3>&1 >/dev/null';
189 $itmp = new File::Temp;
190 $otmp = new File::Temp;
194 open I, "admesh $admesh_stdout $itmp |";
201 if (m/^outer\s+loop/) {
204 } elsif (s/^vertex\s+//) {
207 my @xyz = split /\s+/, $_;
208 die unless $triangle;
209 push @$triangle, \@xyz;
210 } elsif (m/^endloop/) {
211 die unless @$triangle == 3;
213 push @$triangles, $triangle;
215 } elsif (m/^(?:solid|facet\s+normal|endfacet|endsolid)\s/) {
222 <I> if 0; # suppresses Name "main::I" used only once
227 &{ ${*::}{"op__$op"} };
232 print "solid distort-stl\n";
234 foreach my $t (@$triangles) {
235 print " facet normal 0 0 0\n";
236 print " outer loop\n";
238 foreach my $p (@$t) {
241 printf " %.18g", $_ foreach @$p;
248 print "endsolid distort-stl\n";
253 system "admesh --normal-values $admesh_stdout $otmp";