Just to follow up on this, here is an interesting result: I modified
osgDB::DatabasePager so that it discards new file requests when the
_fileRequestList.size() > 25. Now the problem I was seeing is gone and
paging flies, even with >2500 files at the same level. I'm sure this might
result in other side effects but I though it was interesting enough to
post... experimentation continues... -gw

On 3/10/07, Robert Osfield <[EMAIL PROTECTED]> wrote:

HI Glenn,

When doing paging you should also aim to create a hierarchy of
PagedLOD's not a flat structure.  This also applies to LOD scene
graphs, but do to the paging required its more important with
PagedLODs as the paging itself will have t run for each group.

One really needs to decide upon the granularity of your scene graph
too, too fine and your trying to paging into too many separate tiles,
too large and each tile will take too long to load into memory and to
download to the GPU.

Robert.

On 3/9/07, Glenn Waldron <[EMAIL PROTECTED]> wrote:
> Hi,
> I was experimenting with the "osgpagedlod" example and ran into some
strange
> behavior:
>
> I have a database that contains about 2500 buildings, each under its own
LOD
> as the sole child with a range of 0-20000 or so. No terrain, just
buildings
> divided into groups of ~50 buildings each. There are no hierarchical
LODs.
> This runs at a nice 60Hz.
>
> I then ran "osgpagedlod --makeAllChildrenPaged" on the database, ending
up
> with a master file and 2500 subfiles as expected. When I fired it up, it
> would page in about one building every second. While data paged in, the
> stats showed an average cull time of about 750ms and a frame rate of 1.x
> fps.
>
> At first I though it was a texture sharing problem (all buildings have
the
> same one texture) but I removed the texture file and the behavior is the
> same.
>
> Is there an issue with processing this many (non-hierarchical)
PagedLOD's at
> a time? What accounts for the massive cull time? Thanks for an insight
> anyone can provide. -gw
>
> --
> Glenn Waldron : Pelican Mapping : http://pelicanmapping.com
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> http://www.openscenegraph.org/
>
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Glenn Waldron : Pelican Mapping : http://pelicanmapping.com
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