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extruding 2D objects that have been moved off of the Z=0 plane

BC
Bob Carlson
Mon, Aug 11, 2025 5:01 PM

On Aug 10, 2025, at 08:55, Jordan Brown openscad@jordan.maileater.net wrote:

On 8/9/2025 10:14 PM, Bob Carlson wrote:

I am thinking of that cross section in terms of [x, 0, z].

OK.  That would require that polygon() allow you to specify points in 3-space, which it currently does not allow.  Right?

Right

(And then there would be questions about getting the points to be coplanar, which is easy to do precisely if you're axis-aligned, but less easy if not.)

I’ve never run into a case where I would not be aligned with one axis or another.

Sounds like fodder for OEP7: Mixed Dimension Geometry Support https://github.com/openscad/openscad/wiki/OEP7:-Mixed-Dimension-Geometry-Support, if anybody ever takes that on.

It does not sound like you care about the case where you've created something using the 2D primitives (and so it lies in the Z=0 plane) and you've then moved the 2D object out of the Z=0 plane and extruded it.  Right?

Correct

I haven’t thought thru this, but a module that took my 2Din3D shape, moved it to XY, extruded it and moved it back, might be pretty straight forward.

-Bob

> On Aug 10, 2025, at 08:55, Jordan Brown <openscad@jordan.maileater.net> wrote: > > On 8/9/2025 10:14 PM, Bob Carlson wrote: >> I am thinking of that cross section in terms of [x, 0, z]. > OK. That would require that polygon() allow you to specify points in 3-space, which it currently does not allow. Right? > Right > (And then there would be questions about getting the points to be coplanar, which is easy to do precisely if you're axis-aligned, but less easy if not.) > I’ve never run into a case where I would not be aligned with one axis or another. > Sounds like fodder for OEP7: Mixed Dimension Geometry Support <https://github.com/openscad/openscad/wiki/OEP7:-Mixed-Dimension-Geometry-Support>, if anybody ever takes that on. > > It does *not* sound like you care about the case where you've created something using the 2D primitives (and so it lies in the Z=0 plane) and you've then moved the 2D object out of the Z=0 plane and extruded it. Right? > Correct I haven’t thought thru this, but a module that took my 2Din3D shape, moved it to XY, extruded it and moved it back, might be pretty straight forward. -Bob