"Filling" 2D/3D Objects

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"Filling" 2D/3D Objects

DonGar
I've been fiddling with extruding and intersecting 2D shapes.

This has left me really wanting a way to fill any gaps in the the interior of an arbitrary 2D shape.

For example, I'd want an "O" to just become an oval defined by the font, and an "A" to retain to opening across the bottom half unmodified, but be solid in the top half.

Is there any reasonable way to do this?
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Re: "Filling" 2D/3D Objects

doug.moen
There's an old feature request for a "voids()" operator that would let you do this.

But to do this in the present language? I don't see a way.

On 25 August 2017 at 21:41, DonGar <[hidden email]> wrote:
I've been fiddling with extruding and intersecting 2D shapes.

This has left me really wanting a way to fill any gaps in the the interior
of an arbitrary 2D shape.

For example, I'd want an "O" to just become an oval defined by the font, and
an "A" to retain to opening across the bottom half unmodified, but be solid
in the top half.

Is there any reasonable way to do this?



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Re: "Filling" 2D/3D Objects

David Eccles (gringer)
In reply to this post by DonGar
hull() will do this for shapes with a convex external face / edge.
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Re: "Filling" 2D/3D Objects

cacb
On 2017-08-26 22:21, David Eccles (gringer) wrote:
> hull() will do this for shapes with a convex external face / edge.

Yes, but it will fail for the case of a concave 2D shape, e.g. the
"A"-shape as mentioned in the first post. Hull only considers the vertex
coordinates, not the topology of the shape.

Carsten Arnholm

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Re: "Filling" 2D/3D Objects

Ronaldo
In general, we can decompose the outer boundary polygon in convex sets, like is done by minkowski, and union the convex hull of each part. 

Em 27 de ago de 2017 07:39, <[hidden email]> escreveu:
On 2017-08-26 22:21, David Eccles (gringer) wrote:
hull() will do this for shapes with a convex external face / edge.

Yes, but it will fail for the case of a concave 2D shape, e.g. the "A"-shape as mentioned in the first post. Hull only considers the vertex coordinates, not the topology of the shape.

Carsten Arnholm


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Re: "Filling" 2D/3D Objects

cacb
On 2017-08-27 11:46, Ronaldo Persiano wrote:
> In general, we can decompose the outer boundary polygon in convex
> sets, like is done by minkowski, and union the convex hull of each
> part.

You can do that, and thus re-create the input :-)

Carsten Arnholm

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