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 ($$$$) {
48 my ($t, $ok, $changed, $edge_need_subdivide_fn) = @_;
51 "%11.6f,%11.6f,%11.6f / ".
52 "%11.6f,%11.6f,%11.6f / ".
53 "%11.6f,%11.6f,%11.6f ",
54 $t->[0][0], $t->[0][1], $t->[0][2],
55 $t->[1][0], $t->[1][1], $t->[1][2],
56 $t->[2][0], $t->[2][1], $t->[2][2];
58 foreach my $ix (0..2) {
61 if ($edge_need_subdivide_fn->($t->[$ix], $t->[$jx])) {
63 " S i=%d j=%d k=%d \n",
66 foreach my $ci (0..2) {
67 push @midp, 0.5 * ($t->[$ix][$ci] + $t->[$jx][$ci]);
69 # triangle i-j-k, splitting edge i-m
72 [ $t->[$ix], \@midp, $t->[$kx] ],
73 [ $t->[$kx], \@midp, $t->[$jx] ];
78 printf STDERR "OK nok=%d nchanged=%d\n",
79 (scalar @$ok), (scalar @$changed);
82 sub maybe_subdivide ($) {
83 my ($edge_need_subdivide_fn) = @_;
85 my @small_enough = ();
86 while (my $t = shift @$triangles) {
87 maybe_subdivide_triangle $t, \@small_enough, $triangles,
88 $edge_need_subdivide_fn;
91 $triangles = \@small_enough;
94 sub append_triangle ($) {
99 #---------- set-fa ----------
105 #---------- project-cylinder ----------
107 our $project_cylinder_radius;
108 our $project_cylinder_max_d_theta;
110 sub project_cylinder_edge_need_subdivide ($$) {
111 my @thetas = map { $_->[0] / $project_cylinder_radius } @_;
112 return abs($thetas[0] - $thetas[1]) > $project_cylinder_max_d_theta;
115 sub project_cylinder_tri {
118 #print STDERR 'PROJECT', Dumper($t);
120 my $radius = $project_cylinder_radius;
123 foreach my $p (@$t) {
125 my $r = $radius - $y;
126 my $theta = $x / $radius;
127 push @ot, [ $r * sin($theta),
131 append_triangle \@ot;
134 sub op__project_cylinder () {
135 $project_cylinder_radius = shift_arg;
136 $project_cylinder_max_d_theta = $fa * TAU/360;
138 maybe_subdivide \&project_cylinder_edge_need_subdivide;
141 foreach my $t (@$triangles) {
142 project_cylinder_tri $t;
144 $triangles = $output;
147 #---------- main program ----------
151 while (@ARGV && $ARGV[0] =~ m/^-/) {
164 my $admesh_stdout = '--write-ascii-stl /dev/fd/3 3>&1 >/dev/null';
170 $itmp = new File::Temp;
171 $otmp = new File::Temp;
175 open I, "admesh $admesh_stdout $itmp |";
182 if (m/^outer\s+loop/) {
185 } elsif (s/^vertex\s+//) {
188 my @xyz = split /\s+/, $_;
189 die unless $triangle;
190 push @$triangle, \@xyz;
191 } elsif (m/^endloop/) {
192 die unless @$triangle == 3;
193 push @$triangles, $triangle;
195 } elsif (m/^(?:solid|facet\s+normal|endfacet|endsolid)\s/) {
202 <I> if 0; # suppresses Name "main::I" used only once
207 &{ ${*::}{"op__$op"} };
212 print "solid distort-stl\n";
214 foreach my $t (@$triangles) {
215 print " facet normal 0 0 0\n";
216 print " outer loop\n";
218 foreach my $p (@$t) {
221 printf " %.18g", $_ foreach @$p;
228 print "endsolid distort-stl\n";
233 system "admesh --normal-values $admesh_stdout $otmp";