[osg-users] osgTerrain::TerrainTile question

Brian R Hill bhill22 at csc.com
Wed Sep 10 04:54:52 PDT 2008


Nicholas,

If the openflight files are already subdivided into a grid of tiles
referenced into a single master file, then there's some code I posted to
the list a couple months ago that will convert them to use pagelods and
also convert them to .ive format for faster loading.

Search the archives and you should see how to do it.

Brian

-----osg-users-bounces at lists.openscenegraph.org wrote: -----

To: "OpenSceneGraph Users" <osg-users at lists.openscenegraph.org>
From: Coco <vilaincoco at gmail.com>
Sent by: osg-users-bounces at lists.openscenegraph.org
Date: 09/10/2008 05:55AM
Subject: Re: [osg-users] osgTerrain::TerrainTile question

2008/9/10, Robert Osfield <
robert.osfield at gmail.com
>:

Hi Nicolas,

I think you have got the wrong end of the stick.  I was suggesting
TerraPage as an illustration of how cultural data (3d models) can be

stored in with the tiles on disk.  In vis-sim industry TerraPage is
well known so I used it as as a case in point to save typing lots...

FYI, The OSG's TerraPage plugin uses the PagedLOD and the
DatabasePager under the hood to provide it's paging functionality.

In your case the problem is about creating databases not actually
rendering them - as the OSG will do all the paging, and threading for
you thanks the DatabasePager and other related classes.  The
DatabasePage doesn't help you create databases, it's tools like

VirtualPlanetBuilder that do this, but... right now VPB doesn't
support insertion of cultural data into the tiles, so you'll need post
process the database to insert this data.

Robert.





I think there is a missunderstanding. My problem is to load a  big
database, not to create it.

I already have my database, fragmented in FLT files like I said. So I was
suggesting to use DatabasePager to load flt nodes when I need it to. In
this case I think I don't have to process any data...

I hope I haven't got the wrong end of the stick (again!).



Nicolas




On Wed, Sep 10, 2008 at 9:49 AM, Coco <
vilaincoco at gmail.com
> wrote:

> Thank you very much for your ideas!
>
> I found out the osgDB::DatabasePager class by reading old posts and it
looks
> to fit my problem very well.
> By using TerraPage I will have to pre-process my databases, whereas with
the

> database pager I don't need to.
>
> virtual void  requestNodeFile (const std::string &fileName, osg::Group
> *group, float priority, const osg::FrameStamp *framestamp)
> Theoretically, I just have to use this function before the camera is
close

> enough to see next area(s).
>
> Regards,
>
> Nicolas Duval
>
> 2008/9/10, Robert Osfield <
robert.osfield at gmail.com
>:
>>

>> Hi Nicolas,
>>
>> osgTerrain::TerrainTile was named osgTerrain::Terrain in 2.2.
>> osgTerrain since 2.2 was evolved to be more rounded and functional,
>> the naming was changed to better fit what goes on in big paged

>> database, when the Terrain is composed of a hierarchy of TerrainTile.
>> There is now a new class class osgTerrain::Terrain which represent the
>> high level representation of the terrain.
>>

>> In your case loading 3D models with terrain is something that we be
>> best done be pre-processing your data so that the 3D models are
>> inserted into a paged database.  If you are familiar with TerraPage

>> then this ideal should be familiar to you.
>>
>> Robert.
>>
>> On Tue, Sep 9, 2008 at 9:30 PM, Coco <
vilaincoco at gmail.com
> wrote:

>> > Hi,
>> >
>> > I'm presently working on a car simulator using OSG 2.2 for the visual.
>> > My problem is that I would like to load big areas (such as entire
cities
>> > or

>> > more) which are fragmented in several Open Flight files without
loading
>> > all
>> > those files.
>> > I looked at the OSG documentation and found out the
>> > osgTerrain::TerrainTile

>> > class (which doesn't exist on 2.2 OSG version).
>> > By using OSG 2.6, would I be able to load (with the TerrainTile class)
>> > only
>> > tiles (associated to a FLT file) that I need to see (which means

>> > according
>> > to the location of the camera)?
>> > Or do I need to implement this system by myself to avoid loading all
>> > files
>> > at the same time?
>> >

>> > I hope this post is clear enough and wait for answers.
>> >
>> > Kind regards,
>> >
>> > Nicolas Duval
>> > _______________________________________________

>> > osg-users mailing list
>> >
osg-users at lists.openscenegraph.org

>> >
>> >
http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org


>> >
>> >
>> _______________________________________________
>> osg-users mailing list
>>
osg-users at lists.openscenegraph.org


>>
http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org

>
>
> _______________________________________________

> osg-users mailing list
>
osg-users at lists.openscenegraph.org

>
http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org


>
>
_______________________________________________
osg-users mailing list
osg-users at lists.openscenegraph.org

http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org




_______________________________________________
osg-users mailing list
osg-users at lists.openscenegraph.org
http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org





More information about the osg-users mailing list