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 maybe_subdivide_triangle ($$$$) {
48 my ($t, $ok, $changed, $edge_need_subdivide_fn) = @_;
51 "%11.6f,%11.6f,%11.6f / ".
52 "%11.6f,%11.6f,%11.6f / ".
53 "%11.6f,%11.6f,%11.6f %-40s ",
54 $t->[0][0], $t->[0][1], $t->[0][2],
55 $t->[1][0], $t->[1][1], $t->[1][2],
56 $t->[2][0], $t->[2][1], $t->[2][2],
59 foreach my $ix (0..2) {
62 if ($edge_need_subdivide_fn->($t->[$ix], $t->[$jx])) {
67 foreach my $ci (0..2) {
68 push @midp, 0.5 * ($t->[$ix][$ci] + $t->[$jx][$ci]);
70 # triangle i-j-k, splitting edge i-m
72 my $n = [ @$t ]; $n->[$ix] = \@midp; $n->[3] = "$t->[3]a$ix$jx";
73 unshift @$changed, $n;
75 my $n = [ @$t ]; $n->[$jx] = \@midp; $n->[3] = "$t->[3]b$ix$jx";
76 unshift @$changed, $n;
78 " midp %11.6f,%11.6f,%11.6f\n",
84 printf STDERR "OK nok=%d nchanged=%d\n",
85 (scalar @$ok), (scalar @$changed);
88 sub maybe_subdivide ($) {
89 my ($edge_need_subdivide_fn) = @_;
91 my @small_enough = ();
92 while (my $t = shift @$triangles) {
93 maybe_subdivide_triangle $t, \@small_enough, $triangles,
94 $edge_need_subdivide_fn;
97 $triangles = \@small_enough;
100 sub append_triangle ($) {
105 #---------- set-fa ----------
111 #---------- project-cylinder ----------
113 our $project_cylinder_radius;
114 our $project_cylinder_max_d_theta;
116 sub project_cylinder_edge_need_subdivide ($$) {
117 my @thetas = map { $_->[0] / $project_cylinder_radius } @_;
118 return abs($thetas[0] - $thetas[1]) > $project_cylinder_max_d_theta;
121 sub project_cylinder_tri {
124 #print STDERR 'PROJECT', Dumper($t);
126 my $radius = $project_cylinder_radius;
129 foreach my $p (@$t) {
131 my $r = $radius - $y;
132 my $theta = $x / $radius;
133 push @ot, [ $r * sin($theta),
137 append_triangle \@ot;
140 sub op__project_cylinder () {
141 $project_cylinder_radius = shift_arg;
142 $project_cylinder_max_d_theta = $fa * TAU/360;
144 maybe_subdivide \&project_cylinder_edge_need_subdivide;
147 foreach my $t (@$triangles) {
148 project_cylinder_tri $t;
150 $triangles = $output;
153 #---------- main program ----------
157 while (@ARGV && $ARGV[0] =~ m/^-/) {
170 my $admesh_stdout = '--write-ascii-stl /dev/fd/3 3>&1 >/dev/null';
176 $itmp = new File::Temp;
177 $otmp = new File::Temp;
181 open I, "admesh $admesh_stdout $itmp |";
188 if (m/^outer\s+loop/) {
191 } elsif (s/^vertex\s+//) {
194 my @xyz = split /\s+/, $_;
195 die unless $triangle;
196 push @$triangle, \@xyz;
197 } elsif (m/^endloop/) {
198 die unless @$triangle == 3;
200 push @$triangles, $triangle;
202 } elsif (m/^(?:solid|facet\s+normal|endfacet|endsolid)\s/) {
209 <I> if 0; # suppresses Name "main::I" used only once
214 &{ ${*::}{"op__$op"} };
219 print "solid distort-stl\n";
221 foreach my $t (@$triangles) {
222 print " facet normal 0 0 0\n";
223 print " outer loop\n";
225 foreach my $p (@$t) {
228 printf " %.18g", $_ foreach @$p;
235 print "endsolid distort-stl\n";
240 system "admesh --normal-values $admesh_stdout $otmp";