[osg-users] Using Kd-tree for spatial data

maruti borker slimshadymaruti at gmail.com
Fri Sep 5 01:11:36 PDT 2008


But when i went through the discussion, i found out that only geomety in the
leaves have seperate kd-tree and not a single kd-tree for the whole scene.
Correct me if i am wrong.


Maruti Borker
IIIT Hyderabad
Website:- http://students.iiit.ac.in/~maruti
Blog:- http://marutiborker.wordpress.com


On Fri, Sep 5, 2008 at 1:10 PM, Alberto Luaces <aluaces at udc.es> wrote:

> Hi,
>
> it's already done for you. Just use the osg::KdTreeBuilder visitor on the
> subgraph you want to be split with kd-trees.
>
> Alberto
>
> El Jueves 04 Septiembre 2008ES 19:15:21 maruti borker escribió:
> > Thanks for pointing out , i looked into the discussion and i think the
> > current setupd with kd-trees wont help me with my idea. Can anyone point
> me
> > to some tool/project which creates just the kd-tree ( near to optimal )
> > given a 3d scene . Any help would be appreciated.
> >
> > Thanks
> >
> > Maruti Borker
> > IIIT Hyderabad
> > Website:- http://students.iiit.ac.in/~maruti<http://students.iiit.ac.in/%7Emaruti>
> > Blog:- http://marutiborker.wordpress.com
> >
> > On Thu, Sep 4, 2008 at 3:00 PM, Robert Osfield
> <robert.osfield at gmail.com>wrote:
> > > HI Maruti,
> > >
> > > Lots was discussed on osg-users about the KdTree implementation in the
> > > OSG when I intergrated the functionality, so have a look through the
> > > osg-users archives in June and July.   The quick answer is that
> > > KdTree's hang off Drawables, and when do intersection testing first
> > > coarsed grained culling is done by the scene graphs hierachy of
> > > bounding spheres/boxes, then finally fine grained testing is done
> > > against the KdTree hanging of the drawables.
> > >
> > > Robert.
> > >
> > > On Thu, Sep 4, 2008 at 7:27 AM, maruti borker <
> slimshadymaruti at gmail.com>
> > >
> > > wrote:
> > > > Hello,
> > > >                    I was amazed to see the development  OSG has made,
> > > > the last version i used it was 2.3.4. Coming to the topic,  i wanted
> to
> > > > know
> > >
> > > how
> > >
> > > > a scenegraph was being linked to a kd-tree for finding out
> > > > intersections.
> > >
> > > I
> > >
> > > > am thinking of an application which needs querying of spatial data,
> for
> > > > which i thought of using kd-trees , but i also thought of having a
> > > > scenegraph for rendering purposes. I looked at a work "Razor:
> > > > Multi-resolution ray tracing for dynamic environments" by William
> mark
> > >
> > >  and
> > >
> > > > Warren hunt. They also lazily linked a scene-graoh and a kd-tree. I
> > >
> > > wanted
> > >
> > > > to know how the kd-tree is being linked to a scenegraph in OSG and
> also
> > > > whether i could actually access the kd-tree for performing algorithms
> > > > on
> > >
> > > top
> > >
> > > > of it. And also an advice whether using this linkage in OSG is useful
> > > > for storing spatial data. Do mail back incase of any doubts or
> > > > clarifications
> > >
> > > .
> > >
> > > > Maruti Borker
> > > > IIIT Hyderabad
> > > > Website:-
> > > > http://students.iiit.ac.in/~maruti<http://students.iiit.ac.in/%7Emaruti>
> <http://students.iiit.ac.in/%7Emaruti
> > > >> Blog:- http://marutiborker.wordpress.com
> > > >
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> > >
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