newby - help with convex hull

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newby - help with convex hull

GregBerlin
I am just starting to use PCl, converting our existing code to use the various objects (we had our own implementation of pointcloud, octtree etc, but not as good as the pcl).  I want to generate a convex hull of a 3D un organized cloud, but as a 2d object on the base plane.  From my understanding of the convex hull objhect, it will generate a 3d object if I give it a 3d cloud.  How can i get a 2d object?

One other thing I don't understand (from looking at the tea mug sample) is what the segmentation has to do with it.

Thanks in advance.

Greg Berlin
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Re: newby - help with convex hull

Radu B. Rusu
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Greg,


On 03/09/2012 10:07 AM, GregBerlin wrote:
> I am just starting to use PCl, converting our existing code to use the
> various objects (we had our own implementation of pointcloud, octtree etc,
> but not as good as the pcl).  I want to generate a convex hull of a 3D un
> organized cloud, but as a 2d object on the base plane.  From my
> understanding of the convex hull objhect, it will generate a 3d object if I
> give it a 3d cloud.  How can i get a 2d object?

What do you mean by generating a 2D object from a 3D cloud?

> One other thing I don't understand (from looking at the tea mug sample) is
> what the segmentation has to do with it.

What example are you referring to?


PS. We should move this conversation to [hidden email] instead.

Cheers,
Radu.
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Re: newby - help with convex hull

GregBerlin
Whoops - I hadn't noticed that there were 2 mail lists - you are right, this doesn't belong on the developers.

Any way, I figured out what segmentation is, and decided to copy the cloud to a PointXy cloud, and do the convex hull on the resultant projection.