dolfin team mailing list archive

[Andre Massing <massing@xxxxxxxxx>]

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1



On 11/09/2011 03:50 PM, Johan Hake wrote:
> On Wednesday November 9 2011 12:07:57 Andre Massing wrote:
>> Hi!
>> 
>> I have implemented 
>> https://blueprints.launchpad.net/dolfin/+spec/bbtree-all-codim
>> 
>> including some unittests, but there remain some questions.
> 
> Nice!
> 
>> 1. The name IntersectionOperator is kind of unfortunate and
>> cryptic. In the end it is just a wrapper for a bounding box tree
>> so I was thinking about renaming it to something more
>> descriptive, e.g. BoundingVolumeTree or BVTree...Any suggestions,
>> wishes, feelings about that? That brings me to another point.
> 
> I am afraid that BVTree does not tell us too much about what we can
> do with it.

Yes, very true. You have to know what a bbtree is usually used for,
which we cannot /should not expect from the typical user who don't
care much about the implementation details... I am already convinced
that something with Tree would be a bad name.

BVTree is a name which represents the name of the underlying structure
and
> algorithms, right? Can you list possibe things we can do with such
> a beast. Maybe we can find a good name based on that?

You can basically do what a CGAL tree can do which means:
- -find any/all intersections between entities of mesh and another given
entity or point.
- -find the closest point and entity for entities of mesh and given point
- -compute distance between for entities of mesh and given point.

> 
>> 2. Since a bbtree is available for all entity dimension it might
>> be nice to have specialized, ready to use name for them
>> (especially with the python interface in mind and similar to what
>> we have for MeshEntity already)? For instance CellBVTree,
>> FacetBVTree are names popping up in my mind. Are they any
>> suggestions or preferences regarding this?
> 
> Sounds good, if we go with BVTree then ;)

I agree on that we should not :)

> 
>> 3. Johan suggested at some point to expose the distance
>> functions available in CGAL AABBTree
>> 
>> http://www.cgal.org/Manual/latest/doc_html/cgal_manual/AABB_tree_ref/Class_
>>
>> 
AABB_tree.html#Cross_link_anchor_1724
>> 
>> which I think is a good idea.  Any objections for adding that to 
>> DOLFIN?
> 
> Not from me ;)

I kind of guessed that ;)

Andre

> 
> Johan
> 
>> As far as I know of intersection related operations haven't been
>> mentioned in the book, so an interface renaming plus some small
>> localized interface changes won't effect code examples in the
>> book.
>> 
>> Cheers, Andre
>> 
>> _______________________________________________ Mailing list:
>> https://launchpad.net/~dolfin Post to     :
>> dolfin@xxxxxxxxxxxxxxxxxxx Unsubscribe :
>> https://launchpad.net/~dolfin More help   :
>> https://help.launchpad.net/ListHelp
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v2.0.17 (GNU/Linux)
Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/

iQEcBAEBAgAGBQJOuv7WAAoJEA79ggnbq9dmqTgH/2QHS9V3hgfgXuS3C69hf9EU
lijc/EX5K9YEbEl4MKadrMpHgmtO0KHyVPySBHKvaBjKT6XAjAv8gUTlYDLE2fru
4L1U/vj1J5TfsIugedM9S8EYl3b6SmLzkG1WyDqxPOPDkwLdPitzE/Y0veqCkexb
YAGS1uZmwgyI10PdKgIpQkwu7aOwoxZaoIUl0stJPcprIbO9fHw5M9DY/ZlYFNw8
9wUOisCa/bWcNmESNj4UddT2CjycBG+Xm6vSngHyc+EwLpjRfuIFZx1AdxS2+EIU
mJXaZEK+H3z73OFlVFeLerokJhnrIkEP/LxGQITDemOPKbge94iAm05wKJZp8Ns=
=wZ3P
-----END PGP SIGNATURE-----