Re: [osg-users] osgSim HeightAboveTerrain performance...
Hi Shayne, If KdTree aren't helping performance then you either have a bottleneck outside the actual ray to triangle intersection, or perhaps the KdTree's aren't being assigned correctly. Might I suggest you walk through the code in a debugger to see what is going on. Robert. On Thu, Aug 19, 2010 at 10:41 PM, Tueller, Shayne R Civ USAF AFMC 519 SMXS/MXDEC shayne.tuel...@hill.af.mil wrote: Robert, Sorry it has been long giving feedback on this. I've been working other issues. I did try the KdTrees stuff you suggested without any improvement in performance. I called osgDB::Registry::instance()-setBuildKdTreesHint(osgDB::ReaderWriter::Option s::BUILDKDTREES); before I load my terrain database. Is this the correct way to do this? Is there anything else I need to do to enable this or get this to work? In some respects things got even slower than before when I try LOS intersection calculations via the osgSim::LineOfSight class... -Shayne -Original Message- From: osg-users-boun...@lists.openscenegraph.org [mailto:osg-users-boun...@lists.openscenegraph.org] On Behalf Of Robert Osfield Sent: Wednesday, July 28, 2010 2:47 AM To: OpenSceneGraph Users Subject: Re: [osg-users] osgSim HeightAboveTerrain performance... 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 ___ 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
Re: [osg-users] osgSim HeightAboveTerrain performance...
Robert, If I'm using this KdTree feature correctly then perhaps the next step is digging down deeper with a debugger. In my app, I'm collecting both HAT and LOS data on a per frame basis on the terrain. I've narrowed it down to where the intersections are calculated for the LOS set. It appears I get a significant performance hit when I invoke the call: los.computeIntersections(terrain.get()); where terrain is a pagedLOD VPB database and los is an osgSim:LineOfSight class. Once I comment this call out, performance is where it should be. This would seem to suggest that there's no bottleneck outside the ray/triangle intersection but that there are issues with the intersection calculations themselves for LOS... -Shayne -Original Message- From: osg-users-boun...@lists.openscenegraph.org [mailto:osg-users-boun...@lists.openscenegraph.org] On Behalf Of Robert Osfield Sent: Friday, August 20, 2010 2:30 AM To: OpenSceneGraph Users Subject: Re: [osg-users] osgSim HeightAboveTerrain performance... Hi Shayne, If KdTree aren't helping performance then you either have a bottleneck outside the actual ray to triangle intersection, or perhaps the KdTree's aren't being assigned correctly. Might I suggest you walk through the code in a debugger to see what is going on. Robert. On Thu, Aug 19, 2010 at 10:41 PM, Tueller, Shayne R Civ USAF AFMC 519 SMXS/MXDEC shayne.tuel...@hill.af.mil wrote: Robert, Sorry it has been long giving feedback on this. I've been working other issues. I did try the KdTrees stuff you suggested without any improvement in performance. I called osgDB::Registry::instance()-setBuildKdTreesHint(osgDB::ReaderWriter::Option s::BUILDKDTREES); before I load my terrain database. Is this the correct way to do this? Is there anything else I need to do to enable this or get this to work? In some respects things got even slower than before when I try LOS intersection calculations via the osgSim::LineOfSight class... -Shayne -Original Message- From: osg-users-boun...@lists.openscenegraph.org [mailto:osg-users-boun...@lists.openscenegraph.org] On Behalf Of Robert Osfield Sent: Wednesday, July 28, 2010 2:47 AM To: OpenSceneGraph Users Subject: Re: [osg-users] osgSim HeightAboveTerrain performance... 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
Re: [osg-users] osgSim HeightAboveTerrain performance...
Hi Shayne, The LOS and HAT techniques use the osgUtil::IntersectionVisitor and LineSegmentIntersector to the intersection work, and by default add a special callback DatabaseCacheReadCallback that enables the intersection traversal to load external tiles when tiles aren't already in memory. This load is synchronous so it may well be that this is causing the performance hit. You could you try using the basic osgUtil::IntersectionVisitor and LineSegmentIntersector, this won't automatically load higher levels of details, making do with just what is loaded into memory already, but it will at least not require an IO. Robert. On Fri, Aug 20, 2010 at 3:35 PM, Tueller, Shayne R Civ USAF AFMC 519 SMXS/MXDEC shayne.tuel...@hill.af.mil wrote: Robert, If I'm using this KdTree feature correctly then perhaps the next step is digging down deeper with a debugger. In my app, I'm collecting both HAT and LOS data on a per frame basis on the terrain. I've narrowed it down to where the intersections are calculated for the LOS set. It appears I get a significant performance hit when I invoke the call: los.computeIntersections(terrain.get()); where terrain is a pagedLOD VPB database and los is an osgSim:LineOfSight class. Once I comment this call out, performance is where it should be. This would seem to suggest that there's no bottleneck outside the ray/triangle intersection but that there are issues with the intersection calculations themselves for LOS... -Shayne -Original Message- From: osg-users-boun...@lists.openscenegraph.org [mailto:osg-users-boun...@lists.openscenegraph.org] On Behalf Of Robert Osfield Sent: Friday, August 20, 2010 2:30 AM To: OpenSceneGraph Users Subject: Re: [osg-users] osgSim HeightAboveTerrain performance... Hi Shayne, If KdTree aren't helping performance then you either have a bottleneck outside the actual ray to triangle intersection, or perhaps the KdTree's aren't being assigned correctly. Might I suggest you walk through the code in a debugger to see what is going on. Robert. On Thu, Aug 19, 2010 at 10:41 PM, Tueller, Shayne R Civ USAF AFMC 519 SMXS/MXDEC shayne.tuel...@hill.af.mil wrote: Robert, Sorry it has been long giving feedback on this. I've been working other issues. I did try the KdTrees stuff you suggested without any improvement in performance. I called osgDB::Registry::instance()-setBuildKdTreesHint(osgDB::ReaderWriter::Option s::BUILDKDTREES); before I load my terrain database. Is this the correct way to do this? Is there anything else I need to do to enable this or get this to work? In some respects things got even slower than before when I try LOS intersection calculations via the osgSim::LineOfSight class... -Shayne -Original Message- From: osg-users-boun...@lists.openscenegraph.org [mailto:osg-users-boun...@lists.openscenegraph.org] On Behalf Of Robert Osfield Sent: Wednesday, July 28, 2010 2:47 AM To: OpenSceneGraph Users Subject: Re: [osg-users] osgSim HeightAboveTerrain performance... 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
Re: [osg-users] osgSim HeightAboveTerrain performance...
Robert, That sounds like a plausible explanation for the performance hit. I'll investigate further and try the basic ones as you suggest. On a related note, I have a couple of questions... 1) Is there a quick way to obtain the closest intersection for a given LOS? I noticed that for a LOS, all intersections with the terrain are returned which can be large when my ownship gets close to the ground. Right now, I'm searching the returned intersection list and extracting the closest one. 2) Does the LOS technique check for occlusion along a given ray or does it compute every intersection regardless? Are hits with backfaces (as defined relative to the ownship) computed as well? I'm assuming that the computed intersection list is random (i.e. not sorted from closest to farthest from the start point)? Thanks, -Shayne -Original Message- From: osg-users-boun...@lists.openscenegraph.org [mailto:osg-users-boun...@lists.openscenegraph.org] On Behalf Of Robert Osfield Sent: Friday, August 20, 2010 8:48 AM To: OpenSceneGraph Users Subject: Re: [osg-users] osgSim HeightAboveTerrain performance... Hi Shayne, The LOS and HAT techniques use the osgUtil::IntersectionVisitor and LineSegmentIntersector to the intersection work, and by default add a special callback DatabaseCacheReadCallback that enables the intersection traversal to load external tiles when tiles aren't already in memory. This load is synchronous so it may well be that this is causing the performance hit. You could you try using the basic osgUtil::IntersectionVisitor and LineSegmentIntersector, this won't automatically load higher levels of details, making do with just what is loaded into memory already, but it will at least not require an IO. Robert. On Fri, Aug 20, 2010 at 3:35 PM, Tueller, Shayne R Civ USAF AFMC 519 SMXS/MXDEC shayne.tuel...@hill.af.mil wrote: Robert, If I'm using this KdTree feature correctly then perhaps the next step is digging down deeper with a debugger. In my app, I'm collecting both HAT and LOS data on a per frame basis on the terrain. I've narrowed it down to where the intersections are calculated for the LOS set. It appears I get a significant performance hit when I invoke the call: los.computeIntersections(terrain.get()); where terrain is a pagedLOD VPB database and los is an osgSim:LineOfSight class. Once I comment this call out, performance is where it should be. This would seem to suggest that there's no bottleneck outside the ray/triangle intersection but that there are issues with the intersection calculations themselves for LOS... -Shayne -Original Message- From: osg-users-boun...@lists.openscenegraph.org [mailto:osg-users-boun...@lists.openscenegraph.org] On Behalf Of Robert Osfield Sent: Friday, August 20, 2010 2:30 AM To: OpenSceneGraph Users Subject: Re: [osg-users] osgSim HeightAboveTerrain performance... Hi Shayne, If KdTree aren't helping performance then you either have a bottleneck outside the actual ray to triangle intersection, or perhaps the KdTree's aren't being assigned correctly. Might I suggest you walk through the code in a debugger to see what is going on. Robert. On Thu, Aug 19, 2010 at 10:41 PM, Tueller, Shayne R Civ USAF AFMC 519 SMXS/MXDEC shayne.tuel...@hill.af.mil wrote: Robert, Sorry it has been long giving feedback on this. I've been working other issues. I did try the KdTrees stuff you suggested without any improvement in performance. I called osgDB::Registry::instance()-setBuildKdTreesHint(osgDB::ReaderWriter::Option s::BUILDKDTREES); before I load my terrain database. Is this the correct way to do this? Is there anything else I need to do to enable this or get this to work? In some respects things got even slower than before when I try LOS intersection calculations via the osgSim::LineOfSight class... -Shayne -Original Message- From: osg-users-boun...@lists.openscenegraph.org [mailto:osg-users-boun...@lists.openscenegraph.org] On Behalf Of Robert Osfield Sent: Wednesday, July 28, 2010 2:47 AM To: OpenSceneGraph Users Subject: Re: [osg-users] osgSim HeightAboveTerrain performance... 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
Re: [osg-users] osgSim HeightAboveTerrain performance...
Robert, Just as a follow up on the issue at hand, I bumped up the maximum number of files to cache in the DatabaseCacheReadCallback to a higher number than the default 2000. This greatly improved performance. I'm supposing that since there were not as many external paged tiles being read in from disk, this accounted for the performance improvement. This would seem to collaborate your earlier statement that the synchronous load of external tiles was possibly the culprit for my performance degradation... Thanks for your help... -Shayne -Original Message- From: osg-users-boun...@lists.openscenegraph.org [mailto:osg-users-boun...@lists.openscenegraph.org] On Behalf Of Robert Osfield Sent: Friday, August 20, 2010 8:48 AM To: OpenSceneGraph Users Subject: Re: [osg-users] osgSim HeightAboveTerrain performance... Hi Shayne, The LOS and HAT techniques use the osgUtil::IntersectionVisitor and LineSegmentIntersector to the intersection work, and by default add a special callback DatabaseCacheReadCallback that enables the intersection traversal to load external tiles when tiles aren't already in memory. This load is synchronous so it may well be that this is causing the performance hit. You could you try using the basic osgUtil::IntersectionVisitor and LineSegmentIntersector, this won't automatically load higher levels of details, making do with just what is loaded into memory already, but it will at least not require an IO. Robert. On Fri, Aug 20, 2010 at 3:35 PM, Tueller, Shayne R Civ USAF AFMC 519 SMXS/MXDEC shayne.tuel...@hill.af.mil wrote: Robert, If I'm using this KdTree feature correctly then perhaps the next step is digging down deeper with a debugger. In my app, I'm collecting both HAT and LOS data on a per frame basis on the terrain. I've narrowed it down to where the intersections are calculated for the LOS set. It appears I get a significant performance hit when I invoke the call: los.computeIntersections(terrain.get()); where terrain is a pagedLOD VPB database and los is an osgSim:LineOfSight class. Once I comment this call out, performance is where it should be. This would seem to suggest that there's no bottleneck outside the ray/triangle intersection but that there are issues with the intersection calculations themselves for LOS... -Shayne -Original Message- From: osg-users-boun...@lists.openscenegraph.org [mailto:osg-users-boun...@lists.openscenegraph.org] On Behalf Of Robert Osfield Sent: Friday, August 20, 2010 2:30 AM To: OpenSceneGraph Users Subject: Re: [osg-users] osgSim HeightAboveTerrain performance... Hi Shayne, If KdTree aren't helping performance then you either have a bottleneck outside the actual ray to triangle intersection, or perhaps the KdTree's aren't being assigned correctly. Might I suggest you walk through the code in a debugger to see what is going on. Robert. On Thu, Aug 19, 2010 at 10:41 PM, Tueller, Shayne R Civ USAF AFMC 519 SMXS/MXDEC shayne.tuel...@hill.af.mil wrote: Robert, Sorry it has been long giving feedback on this. I've been working other issues. I did try the KdTrees stuff you suggested without any improvement in performance. I called osgDB::Registry::instance()-setBuildKdTreesHint(osgDB::ReaderWriter::Option s::BUILDKDTREES); before I load my terrain database. Is this the correct way to do this? Is there anything else I need to do to enable this or get this to work? In some respects things got even slower than before when I try LOS intersection calculations via the osgSim::LineOfSight class... -Shayne -Original Message- From: osg-users-boun...@lists.openscenegraph.org [mailto:osg-users-boun...@lists.openscenegraph.org] On Behalf Of Robert Osfield Sent: Wednesday, July 28, 2010 2:47 AM To: OpenSceneGraph Users Subject: Re: [osg-users] osgSim HeightAboveTerrain performance... 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
Re: [osg-users] osgSim HeightAboveTerrain performance...
Robert, Sorry it has been long giving feedback on this. I've been working other issues. I did try the KdTrees stuff you suggested without any improvement in performance. I called osgDB::Registry::instance()-setBuildKdTreesHint(osgDB::ReaderWriter::Option s::BUILDKDTREES); before I load my terrain database. Is this the correct way to do this? Is there anything else I need to do to enable this or get this to work? In some respects things got even slower than before when I try LOS intersection calculations via the osgSim::LineOfSight class... -Shayne -Original Message- From: osg-users-boun...@lists.openscenegraph.org [mailto:osg-users-boun...@lists.openscenegraph.org] On Behalf Of Robert Osfield Sent: Wednesday, July 28, 2010 2:47 AM To: OpenSceneGraph Users Subject: Re: [osg-users] osgSim HeightAboveTerrain performance... 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 smime.p7s Description: S/MIME cryptographic signature ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
Re: [osg-users] osgSim HeightAboveTerrain performance...
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
Re: [osg-users] osgSim HeightAboveTerrain performance...
Hi Shayne, Also, if you're intersecting against a PagedLOD database the highest level of detail of the database is loaded and cached by the DatabaseReadCallback in the osgSim::HeightAboveTerrain class. So if your intersections are grouped spatially together they have a better chance of being able to use what is in the memory cache and don't need to load anything from disk. If you're doing random intersections all over the database then there is a greater chance that it will need to load files from disk and slow things down. Thanks, Jason On Wed, Jul 28, 2010 at 4:47 AM, Robert Osfield robert.osfi...@gmail.com wrote: 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 ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
Re: [osg-users] osgSim HeightAboveTerrain performance...
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 smime.p7s Description: S/MIME cryptographic signature ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
Re: [osg-users] osgSim HeightAboveTerrain performance...
Hi, I am not using this functionality at the moment but I do plan on doing so in the relatively near future. As such, please keep posting any findings you make. If it looks like some modifications to the code could help performance I would be willing to chip in some effort. Cheers, Brad -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: Wednesday, 28 July 2010 2:26 AM To: OpenSceneGraph Users Subject: Re: [osg-users] osgSim HeightAboveTerrain performance... 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 DISCLAIMER:--- This e-mail transmission and any documents, files and previous e-mail messages attached to it are private and confidential. They may contain proprietary or copyright material or information that is subject to legal professional privilege. They are for the use of the intended recipient only. Any unauthorised viewing, use, disclosure, copying, alteration, storage or distribution of, or reliance on, this message is strictly prohibited. No part may be reproduced, adapted or transmitted without the written permission of the owner. If you have received this transmission in error, or are not an authorised recipient, please immediately notify the sender by return email, delete this message and all copies from your e-mail system, and destroy any printed copies. Receipt by anyone other than the intended recipient should not be deemed a waiver of any privilege or protection. Thales Australia does not warrant or represent that this e-mail or any documents, files and previous e-mail messages attached are error or virus free. -- ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
[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 smime.p7s Description: S/MIME cryptographic signature ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
