Traversing the vicinity faces of a given vertex on a polyhedron

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Traversing the vicinity faces of a given vertex on a polyhedron

Xiaofan Li-2
Hi everybody,
 
Just want to know what is the most efficient way to find out all facets (or vertices) within the vicinity (radius) r of a given vertex? I don't want to use global facets/vertex circulators as the mesh is quite large, but want to start from the known vertex where its adjacent halfedges and facets are known. But the question then becomes, how to implement a traverse algorithm to search around the given vertex? Does CGAL provide this functionality or does anyone of you could give me some hints on how to implement this?
 
Thanks a lot in advance.
 
Regards,
Xiaofan
 
------------------------------------------------
Xiaofan Li
 
Biomolecular Modeling Laboratory
Cancer Research UK, London Research Institute
 
Department of Biochemistry and Molecular Biology
University College London
------------------------------------------------
 
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RE: Traversing the vicinity faces of a given vertex on a polyhedron

Xiaofan Li-2
Just to make this a bit more clear -- I want to traverse within a give radius R which can include more than 1 layer of the facets. So local circulator such as halfedge_around_facet_circulator won't work straightaway either.

________________________________

From: Xiaofan Li [mailto:[hidden email]]
Sent: Thu 7/31/2008 03:17
To: [hidden email]
Subject: [cgal-discuss] Traversing the vicinity faces of a given vertex on a polyhedron


Hi everybody,
 
Just want to know what is the most efficient way to find out all facets (or vertices) within the vicinity (radius) r of a given vertex? I don't want to use global facets/vertex circulators as the mesh is quite large, but want to start from the known vertex where its adjacent halfedges and facets are known. But the question then becomes, how to implement a traverse algorithm to search around the given vertex? Does CGAL provide this functionality or does anyone of you could give me some hints on how to implement this?
 
Thanks a lot in advance.
 
Regards,
Xiaofan
 
------------------------------------------------
Xiaofan Li
 
Biomolecular Modeling Laboratory
Cancer Research UK, London Research Institute
[hidden email] <mailto:[hidden email]>  
 
Department of Biochemistry and Molecular Biology
University College London
[hidden email] <mailto:[hidden email]>  
------------------------------------------------
 
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Re: Traversing the vicinity faces of a given vertex

andreas.fabri
Hello,

There is no such function.  Also it is not cleasr to me if your radius
is on the surface or in the 3D space. In the latter case you could
have points which are far away on the surface but close in space.
Even if you are only intersted in those close on the surface, things
can be complicated if the faces of the polyhedron are not convex

andreas

Xiaofan Li wrote:

> Just to make this a bit more clear -- I want to traverse within a give radius R which can include more than 1 layer of the facets. So local circulator such as halfedge_around_facet_circulator won't work straightaway either.
>
> ________________________________
>
> From: Xiaofan Li [mailto:[hidden email]]
> Sent: Thu 7/31/2008 03:17
> To: [hidden email]
> Subject: [cgal-discuss] Traversing the vicinity faces of a given vertex on a polyhedron
>
>
> Hi everybody,
>  
> Just want to know what is the most efficient way to find out all facets (or vertices) within the vicinity (radius) r of a given vertex? I don't want to use global facets/vertex circulators as the mesh is quite large, but want to start from the known vertex where its adjacent halfedges and facets are known. But the question then becomes, how to implement a traverse algorithm to search around the given vertex? Does CGAL provide this functionality or does anyone of you could give me some hints on how to implement this?
>  
> Thanks a lot in advance.
>  
> Regards,
> Xiaofan
>  
> ------------------------------------------------
> Xiaofan Li
>  
> Biomolecular Modeling Laboratory
> Cancer Research UK, London Research Institute
> [hidden email] <mailto:[hidden email]>  
>  
> Department of Biochemistry and Molecular Biology
> University College London
> [hidden email] <mailto:[hidden email]>  
> ------------------------------------------------
>  

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RE: Traversing the vicinity faces of a given vertex

Xiaofan Li-2
Hi Andreas,
 
Thanks for the info. I want only continuous surface patch around a given vertex, satisfying a geometric constraint. And the Polyhedron is triangle-only. Any more ideas?
 
Regards
Xiaofan

________________________________

From: Andreas Fabri [mailto:[hidden email]]
Sent: Thu 7/31/2008 10:18
To: [hidden email]
Subject: Re: [cgal-discuss] Traversing the vicinity faces of a given vertex



Hello,

There is no such function.  Also it is not cleasr to me if your radius
is on the surface or in the 3D space. In the latter case you could
have points which are far away on the surface but close in space.
Even if you are only intersted in those close on the surface, things
can be complicated if the faces of the polyhedron are not convex

andreas

Xiaofan Li wrote:

> Just to make this a bit more clear -- I want to traverse within a give radius R which can include more than 1 layer of the facets. So local circulator such as halfedge_around_facet_circulator won't work straightaway either.
>
> ________________________________
>
> From: Xiaofan Li [mailto:[hidden email]]
> Sent: Thu 7/31/2008 03:17
> To: [hidden email]
> Subject: [cgal-discuss] Traversing the vicinity faces of a given vertex on a polyhedron
>
>
> Hi everybody,
>
> Just want to know what is the most efficient way to find out all facets (or vertices) within the vicinity (radius) r of a given vertex? I don't want to use global facets/vertex circulators as the mesh is quite large, but want to start from the known vertex where its adjacent halfedges and facets are known. But the question then becomes, how to implement a traverse algorithm to search around the given vertex? Does CGAL provide this functionality or does anyone of you could give me some hints on how to implement this?
>
> Thanks a lot in advance.
>
> Regards,
> Xiaofan
>
> ------------------------------------------------
> Xiaofan Li
>
> Biomolecular Modeling Laboratory
> Cancer Research UK, London Research Institute
> [hidden email] <mailto:[hidden email]>
>
> Department of Biochemistry and Molecular Biology
> University College London
> [hidden email] <mailto:[hidden email]>
> ------------------------------------------------
>
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To unsubscribe or access the archives, go to
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