Linear cell complex: facet membership query

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Linear cell complex: facet membership query

Pranav
This post was updated on .
Hi,

I have a tetrahedral mesh represented using Linear cell complex. I want to perform queries like if a given facet(say a triangle) is present in the given linear cell complex. It seems like applying are_facets_same_geometry() will solve the problem but I am not sure how to ensure facets to have reverse orientations beforehand? Or, if there is any other approach for the same?

With regards,
Pranav
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Re: Linear cell complex: facet membership query

Pranav
I also would like to add my original problem to the description:
Given 2 linear cell complexes(say lcc1 and lcc2), determine if all 2-cells(facets) of lcc1 are present in lcc2.

For this problem, is it meaningful to convert lcc1 and lcc2 to corresponding Nef polyhedrons and perform boolean operations to extract facets which are present in lcc1 but not in lcc2? Actually, I suspect validity of this approach because from documentation of Linear cell complex and Nef polyhedron it seems that Linear cell complex are more general in terms of their capability to model domains than Nef polyhedron.
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Re: Linear cell complex: facet membership query

Guillaume Damiand
Le 25/01/2016 07:15, Pranav a écrit :

> I also would like to add my original problem to the description:
> /Given 2 linear cell complexes(say lcc1 and lcc2), determine if all
> 2-cells(facets) of lcc1 are present in lcc2. /
>
> For this problem, is it meaningful to convert lcc1 and lcc2 to corresponding
> Nef polyhedrons and perform boolean operations to extract facets which are
> present in lcc1 but not in lcc2? Actually, I suspect validity of this
> approach because from documentation of Linear cell complex and Nef
> polyhedron it seems that Linear cell complex are more general in terms of
> their capability to model domains than Nef polyhedron.

I am not sure converting the two lcc into nef polyhedrons is the best
way to do that.

It is easy to modify the are_facets_same_geometry function to test if
two faces have the same geometry and the same orientation (replace 0 by 1).

Then you can use the same principle than the one used in the function
sew3_same_facets to retreive the faces having the same geometry.

Guillaume




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>


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Re: Linear cell complex: facet membership query

Pranav
Guillaume Damiand wrote
It is easy to modify the are_facets_same_geometry function to test if
two faces have the same geometry and the same orientation (replace 0 by 1).
If I want are_facets_same_geometry function to compare only geometry and disregard relative orientation of the input facets, do I need to modify it to check for equality of points in both orientations, returning True if points are same in either orientation?
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Re: Linear cell complex: facet membership query

Guillaume Damiand
Le 25/01/2016 12:35, Pranav a écrit :
> Guillaume Damiand wrote
>> It is easy to modify the are_facets_same_geometry function to test if
>> two faces have the same geometry and the same orientation (replace 0 by
>> 1).
> If I want /are_facets_same_geometry/ function to compare only geometry and
> disregard relative orientation of the input facets, do I need to modify it
> to check for equality of points in both orientations, returning True if
> points are same in either orientation?

Yes.

>
>
>
>
> --
> View this message in context: http://cgal-discuss.949826.n4.nabble.com/Linear-cell-complex-facet-membership-query-tp4661486p4661516.html
> Sent from the cgal-discuss mailing list archive at Nabble.com.
>


--
===================================================================
Guillaume DAMIAND

CNRS - LIRIS UMR 5205
Université Claude Bernard
Bâtiment Nautibus (710)
43 Boulevard du 11 Novembre 1918
69622 Villeurbanne Cedex (France)
-------------------------------------------------------------------
Tél: +33 (0)4.72.43.14.34                 Fax: +33 (0)4.72.43.15.36
Mail: [hidden email]
Web: http://liris.cnrs.fr/guillaume.damiand/
===================================================================



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