Hi Shyane,

I've not been at my desk too consistently this last few weeks due to
school holidays, so not able to dig down into all threads.

A couple of general comments.  If intersections are slow then consider
enabling the building KdTree's on your scene graph, this will greatly
improve performance.  In osgDB::Options and osgDB::Registry there is a
setBuildKdTreesHint(..) method that you can use.

Robert.

On Tue, Jul 27, 2010 at 7:25 PM, Tueller, Shayne R Civ USAF AFMC 519
SMXS/MXDEC <shayne.tuel...@hill.af.mil> wrote:
> Since I didn't receive any input or feedback on my previous inquiry, I'm
> assuming no one has used osgSim very much in an extensive setting.?.?
>
> At any rate, I've done some further investigation. It appears that
> performance is very poor when HAT inquiries are randomly called in different
> portions of the code via the
> osgSim::HeightAboveTerrain::computeHeightAboveTerrain(.) method. On the
> other hand, if HAT points via hat.addPoint() are collected up and then
> computed (intersections) in one place, performance improves. I'm assuming
> that this is the correct usage for OSG? If this is true, I must say that
> this is a major problem since HAT inquiries need to be done at different
> times throughout the application due to dependencies on HAT for other
> calculations.
>
> I would like some feedback from someone in the know on osgSim so I know what
> the proper usage is for maximum performance. If it is true that all HAT
> points in OSG need to be consolidated for intersection calculation, then I
> will attempt to refactor the code to support what OSG wants.
>
> Thanks,
> -Shayne
>
> -----Original Message-----
> From: osg-users-boun...@lists.openscenegraph.org
> [mailto:osg-users-boun...@lists.openscenegraph.org] On Behalf Of
> Tueller,Shayne R Civ USAF AFMC 519 SMXS/MXDEC
> Sent: Friday, July 23, 2010 10:57 AM
> To: OpenSceneGraph Users
> Subject: [osg-users] osgSim HeightAboveTerrain performance...
>
> All,
>
>
>
> I was wanting some feedback for those who have used osgSim in querying VPB
> database info such has HAT, LOS, etc., during runtime.
>
>
>
> I'm seeing some performance issues when using
> osgSim::HeightAboveTerrain::computeHeightAboveTerrain(.) to get the HAT
> value for a particular location in the database. At times, we need multiple
> HAT values per frame which seems to bog the performance down. I would
> surmise that LOS calculations are probably worse since multiple
> intersections are computed.
>
>
>
> My question is, is how efficient is the osgSim HAT function? Is the process
> of retrieving HAT a slow one? If so, is there a way to improve performance
> if one or more HAT requests are issued on a per frame basis?
>
>
>
> Thanks in advance,
>
> -Shayne
>
>
> _______________________________________________
> osg-users mailing list
> osg-users@lists.openscenegraph.org
> http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
>
>
_______________________________________________
osg-users mailing list
osg-users@lists.openscenegraph.org
http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org

Reply via email to