intersection-or-diff.
Hi,
I want to cut objects into two (or more) puzzle-pieces by defining the
shape of the cut (in various ways).
So in normal operation I have
difference () {
theobject ();
thecutshape ();
}
but for viewing, it is useful to view the cut-shape, but only inside
the object. So then that becomes:
intersection () {
theobject ();
thecutshape ();
}
now I want to change the module intersection for difference depending
on a variable. While writing this I thought: obviously
if (test)
intersection ()
else
difference () {
theobject ();
thecutshape ();
}
won't work.... waitaminute... So I tested it and it doesn't.
Is there a reasonably elegant way of doing this?
While writing this I've come up with
module diff_or_intersect ()
{
if (test) intersection () children ();
else difference () children ();
}
maybe separate out the first child, but this can probably
be made to work. Anybody know of a more elegant way of doing this?
Roger.
--
** R.E.Wolff@BitWizard.nl ** https://www.BitWizard.nl/ ** +31-15-2049110 **
** Delftechpark 11 2628 XJ Delft, The Netherlands. KVK: 27239233 **
f equals m times a. When your f is steady, and your m is going down
your a** is going up. -- Chris Hadfield about flying up the space shuttle.
** 'a' for accelleration.
On 12/7/2024 2:44 AM, Rogier Wolff via Discuss wrote:
module diff_or_intersect ()
{
if (test) intersection () children ();
else difference () children ();
}
I think this will work, but don't have time to test it right now:
module diff_or_intersect ()
{
if (test) {
intersection_for (i=[0:1:$children-1])
children(i);
else {
difference () {
children(0);
children([1:1:$children-1]);
}
}
}
On 12/7/2024 5:21 AM, Jordan Brown wrote:
On 12/7/2024 2:44 AM, Rogier Wolff via Discuss wrote:
module diff_or_intersect ()
{
if (test) intersection () children ();
else difference () children ();
}
It always happens - I remember something the moment after hitting Send.
This won't work because children() yields the union of all of the
children of the current module, and for intersection() and difference()
you need them separated. For intersection() you need each one separate;
for difference() you only need the first separated.
This works on m computer
a=3;
if (a<2) // test
{
difference(){
sphere(20);
cylinder(h=40,r=8);}
}
else {
intersection(){
sphere(20);
cylinder(h=40,r=8);
}
}
On Sat, 7 Dec 2024 at 16:53, Rogier Wolff via Discuss <
discuss@lists.openscad.org> wrote:
Hi,
I want to cut objects into two (or more) puzzle-pieces by defining the
shape of the cut (in various ways).
So in normal operation I have
difference () {
theobject ();
thecutshape ();
}
but for viewing, it is useful to view the cut-shape, but only inside
the object. So then that becomes:
intersection () {
theobject ();
thecutshape ();
}
now I want to change the module intersection for difference depending
on a variable. While writing this I thought: obviously
if (test)
intersection ()
else
difference () {
theobject ();
thecutshape ();
}
won't work.... waitaminute... So I tested it and it doesn't.
Is there a reasonably elegant way of doing this?
While writing this I've come up with
module diff_or_intersect ()
{
if (test) intersection () children ();
else difference () children ();
}
maybe separate out the first child, but this can probably
be made to work. Anybody know of a more elegant way of doing this?
Roger.
--
** R.E.Wolff@BitWizard.nl ** https://www.BitWizard.nl/ ** +31-15-2049110
**
** Delftechpark 11 2628 XJ Delft, The Netherlands. KVK: 27239233 **
f equals m times a. When your f is steady, and your m is going down
your a** is going up. -- Chris Hadfield about flying up the space shuttle.
** 'a' for accelleration.
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