bugpyFormex - Bugs: bug #43971, extension of Mesh.levelVolume for...

 
 

bug #43971: extension of Mesh.levelVolume for lower entities ?

Submitted by:  francesco <francio>
Submitted on:  Sat 10 Jan 2015 09:27:24 PM UTC  
 
Category: CoreSeverity: 1 - Wish
Item Group: Feature requestStatus: Fixed
Privacy: PublicAssigned to: Benedict Verhegghe <bverheg>
Open/Closed: Closed

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Wed 14 Jan 2015 02:52:39 PM UTC, comment #3:

In commit 0606831 we added two new Mesh methods:

faceMesh: returns a Mesh with the unique faces
edgeMesh: returns a Mesh with the unique edges

Benedict Verhegghe <bverheg>
Project AdministratorIn charge of this item.
Wed 14 Jan 2015 01:27:47 PM UTC, comment #2:

I will explain my problem

I need to compute the lengths of the triangulated mesh (so level 2 ). There are many algorythms for mesh editing that require to compute weigths based on tangent on cotangent of the triangles which need a lot of operation on edge length.
so while I think it make sense to use solution 1 for surfaces I am wondering if there is any case in which the areas or the lengths are needed for level 3 (if not on the border). so indeed maybe we have to leave it to the user.

Maybe we can just introduce utility funcions to create lower entities mesh? and then call the levelVolumes. Something like

VolumeMesh.getEdgeMesh().lengths()

which is nicer than

Mesh(VolumeMesh.coords,VolumeMesh.getEdges).lengths()

francesco <francio>
Project Member
Mon 12 Jan 2015 08:52:56 AM UTC, comment #1:

There are two problems here:

1. Length, area, volume are the size of resp. a 1D, 2D, 3D object. We could define them for an object of the next higher level, by posing it is the size of the border of the object.
But that would still leave the length of a 3D object undefined.

2. The levelVolumes are (often) computed by subdividing the elements in subelements, resulting in improper computation of the border (and any lower entity) sizes.

So I think the best solution is to construct the appropriate Mesh of lower entities and take the levelVolumes of that level.
We could leave this completely to the user (using getLowerEntities or getBorder or equivalents) and then calling appropriately lengths, areas or volumes.
Or we can implement the solutions according to 1. above:
- in Mesh.areas for level 3
- in Mesh.lengths for level 2

Benedict Verhegghe <bverheg>
Project AdministratorIn charge of this item.
Sat 10 Jan 2015 09:27:24 PM UTC, original submission:

Can we allow to compute also lenghts and areas for elements with dimensionality 3 and lengths for dimensionality 2

francesco <francio>
Project Member

 

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  • -unavailable- added by francio (Submitted the item)
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    Follow 3 latest changes.

    Date Changed By Updated Field Previous Value => Replaced By
    Wed 14 Jan 2015 02:52:39 PM UTCbverhegStatusNone=>Fixed
      Assigned toNone=>bverheg
      Open/ClosedOpen=>Closed

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