The second problem is a bit more sophisticated. The polygon you feed into
vec3D() is not 2D. It is 3D already and - what seems to be the problem -
not-planar. Even sweep(), at least in theory, can work with this, it relies
on CGAL to deliver a sober triangulation for the caps.
I haven't diven deeper into sweeps with non-planar polygons, but I suspect
that these problems arise with alternate constructions done by CGAL.
My advice (work around): Use only planar polygons, which you get by a 2D
definition, use vec3D to embed it to 3D and transform it. This is the
scenario sweep() was developed for.
After that you can fine-tune the extrusion, e.g. by differencing or unioning
it with a polyhedron or any other union of 3D objects that alter the shape
of the planar caps.
To better see what's going on: The following code will create a one-slice
extrusion (shown as image)
RWALL = gen_outside_RW(RWING,1);
translate([0,0.3,0]) sweep(RWALL);
The second problem is a bit more sophisticated. The polygon you feed into
vec3D() is not 2D. It is 3D already and - what seems to be the problem -
not-planar. Even sweep(), at least in theory, can work with this, it relies
on CGAL to deliver a sober triangulation for the caps.
I haven't diven deeper into sweeps with non-planar polygons, but I suspect
that these problems arise with alternate constructions done by CGAL.
My advice (work around): Use only planar polygons, which you get by a 2D
definition, use vec3D to embed it to 3D and transform it. This is the
scenario sweep() was developed for.
After that you can fine-tune the extrusion, e.g. by differencing or unioning
it with a polyhedron or any other union of 3D objects that alter the shape
of the planar caps.
To better see what's going on: The following code will create a one-slice
extrusion (shown as image)
>
> RWALL = gen_outside_RW(RWING,1);
> translate([0,0.3,0]) sweep(RWALL);
which - to my surprise - still seems to work well. But once you use a second
slice *gen_outside_RW(RWING,2);*, the construction seems to fail.
Nice (and mighty) approach, btw., but it has its caveats and will need some
analysis first to get some rules how it can be used and where are the
limits.
<http://forum.openscad.org/file/n18943/jonker1.png>
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