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Hi all,

Below is a perl script to take a bunch of angles and convert them to points on the edge of a circle primitve (ie. a 16 or 48 point polygon). The comments up top describe how to use it. It's designed to make generating rims on the bottom of curved parts relatively easy when there's only a few segments required and hand-coding makes more sense than using Philo's wonderful toys.

Tim

Code:
#! /usr/bin/perl

# ang2point.pl [-r RAD] [-t THICK] [-s SEGS] ang1 ang2 ... angn

#

# RAD defaults to 20

# THICK defaults to none

# SEGS defaults to 16

#

# Projects the angles onto a circular primitive of radius RAD

# with SEGS segments. If THICK is specified it also shows the

# points on an inner radius of RAD-THICK

#

# It scales the radius at each angle to ensure it lies on the

# SEG-sided polygon that approximates the circle.

#

use POSIX;

$rad=20;

$segs=16;

@angs=();

$thick=0;

for ($ia=0; $ia<=$#ARGV; $ia++) {

    $opt=lc($ARGV[$ia]);

    if ($opt eq '-r') {

    $ia++;

    $rad=$ARGV[$ia];

    } elsif ($opt eq '-t') {

    $ia++;

    $thick=$ARGV[$ia];

    } elsif ($opt eq '-s') {

    $ia++;

    $segs=$ARGV[$ia];

    } else {

    push @angs, $opt;

    }

}

$nang=$#angs+1;

print "0 // ang2point.pl ".join(' ', @ARGV)."\n";

print "0 // Calculating $nang points at outer radius $rad on $segs segments\n";

if ($thick>0) {

    $radp=$rad-$thick;

    print "0 // Also calculating inner radius $radp\n";

}

@reffs=();

@rieffs=();

$kk=3.141592635/180;

foreach $ang (@angs) {

    $f=$ang/360;

    $a0=floor($f*$segs)/$segs*360;

    $ar=$ang-$a0;

    #print "$a0 + $ar\n";

    $c0=cos($kk*$a0);

    $s0=sin($kk*$a0);

    $cf=cos($kk*($a0+360/$segs));

    $sf=sin($kk*($a0+360/$segs));

    $ct=cos($kk*$ang);

    $st=sin($kk*$ang);

    $scale=($c0*$sf-$s0*$cf)/(($sf-$s0)*$ct-($cf-$c0)*$st);

    $reff=$scale*$rad;

    $rieff=$scale*($rad-$thick);

    #print "Effective radius $reff\n";

    push @reffs, $reff;

    push @rieffs, $rieff;

}

@pts=();

@ipts=();

foreach $ia (0..$#angs) {

    $x=$reffs[$ia]*cos($kk*$angs[$ia]);

    $z=$reffs[$ia]*sin($kk*$angs[$ia]);

    push @pts, sprintf("0 // Point %2d: %.3f 0 %.3f\n",

               $ia+1, $x, $z);

    if ($thick>0) {

    $x=$rieffs[$ia]*cos($kk*$angs[$ia]);

    $z=$rieffs[$ia]*sin($kk*$angs[$ia]);

    push @ipts, sprintf("0 // Inner point %2d: %.3f 0 %.3f\n",

                $ia+1, $x, $z);

    }

}

print @pts;

print @ipts;

Looks interesting - I agree that my "wonderful" tools can be clumsy to use Wink

Would you have a sample run (not so familar with perl...)

Not so much clumsy in this case as not quite the right tool for the job. That said I'll be using ytruder for certain Smile

I plan to demonstrate it properly when I get a chance to redo the base of 65188. I'll try to remember to snap the stages. But...

Code:
// ang2point.pl -r 120 -t 4 -s 48 0 7.5 11

// Calculating 3 points at outer radius 120 on 48 segments

// Also calculating inner radius 116

// Point  1: 120.000 0 0.000

// Point  2: 118.973 0 15.663

// Point  3: 117.544 0 22.848

// Inner point  1: 116.000 0 0.000

// Inner point  2: 115.008 0 15.141

// Inner point  3: 113.626 0 22.087

Tim

PS. This one should be very easy to convert to C. But processing arguments is simpler in perl so I chose that option.

And to follow up:

Attached is the stages I took. Finally I ran ytruder on it Smile

Tim Gould

Philippe Hurbain

Tim Gould

Tim Gould