Re: [osg-users] LOD: discrete or continuous?
The VirtualTerrainProject CLOD I believe is aimed at terrain CLODs tend to lend themselves to flatter surfaces such as terrain and generally terrain can be relatively straightforward to create low levels of detail for due to the relationship of the posts and height fields With arbitrary objects it becomes much more complicated and computationally expensive and very hard with any complicated or organically shaped objects, I have not come a across a useable real-time CLOD for objects If you find one or add to OSG that would be a valuable addition Q: " is there a possibility to load only a level of detail which can be computed in for example 30fps minimum?" Yes you could do this, that's how my CLODs work there is a target frame rate or max tris and the level of detail is controlled to get the target frame rate or tri's per frame etc. As to normal LOD's yes you could create a discrete LOD that changes based on target frame rates other tools kit such as Vega/Vega Prime had such stress based loding available. At this time I don't believe there is a stress based LOD change mechanism in OSG, you will have to write such a beast, which again would be a good addition to OSG IHMO, Capture the magic of Christmas this year see http://www.capturethemagic.com __ Gordon Tomlinson gor...@gordontomlinson.com IM: gordon3db...@3dscenegraph.com www.vis-sim.com www.gordontomlinson.com __ -Original Message- From: osg-users-boun...@lists.openscenegraph.org [mailto:osg-users-boun...@lists.openscenegraph.org] On Behalf Of hanne...@gmx.at Sent: Saturday, December 13, 2008 5:29 AM To: OpenSceneGraph Users Subject: Re: [osg-users] LOD: discrete or continuous? Robert Osfield wrote: > Hi Yong, > > On Fri, Dec 12, 2008 at 2:53 PM, Yong Wang wrote: >> Does OSG support continuous Level of Detail? Or support only discrete LOD? > > The core OSG only includes discete LOD, but it's possible to extend > the OSG to provide CLOD. The VirtualTerrainProject has a number of > CLOD implementations that extend the OSG. does this clod work also for buildings and other objects like cars and so on? is there a possibility to load only a level of detail which can be computed in for example 30fps minimum? best regards ___ 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] LOD: discrete or continuous?
Robert Osfield wrote: Hi Yong, On Fri, Dec 12, 2008 at 2:53 PM, Yong Wang wrote: Does OSG support continuous Level of Detail? Or support only discrete LOD? The core OSG only includes discete LOD, but it's possible to extend the OSG to provide CLOD. The VirtualTerrainProject has a number of CLOD implementations that extend the OSG. does this clod work also for buildings and other objects like cars and so on? is there a possibility to load only a level of detail which can be computed in for example 30fps minimum? best regards ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
Re: [osg-users] LOD: discrete or continuous?
HI Alejandro, On Fri, Dec 12, 2008 at 6:25 PM, Alejandro Aguilar Sierra wrote: >> But by all means go spend time on stuff that isn't really useful... > > I rather would like to contribute vpb with useful stuff. IMHO there > is yet room for improvement, and I would be more than happy to > contribute. If just we had better documentation. ;-) if just had a clone of me... BTW, the way to do CLOD these days would be to create a custom osgTerrain::TerrainTechnique, this way you could then use CLOD with VPB generated databases. Robert. ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
Re: [osg-users] LOD: discrete or continuous?
Hi Robert, > ChunkLOD is not CLOD, it's a static paged database, which really is > far less use than what the OSG provides natively with its > DatabasePager with VirtualPlanetBuilder generating the databases. Exactly, your current implementation is much better than the old OSG ready ones you can find at VTP. > As for CLOD implementations, most don't scale well, don't handle > geocentric databases, and most don't perform particular well in > comparison to static paged databases. > Personally I think CLOD is not as useful as it once was, the balance > between GPU power and bandwidth/CPU power has drastically altered in > the last five years, what made sense five years ago really doesn't > these days. Ok. > But by all means go spend time on stuff that isn't really useful... I rather would like to contribute vpb with useful stuff. IMHO there is yet room for improvement, and I would be more than happy to contribute. If just we had better documentation. ;-) Regards. -- A. ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
Re: [osg-users] LOD: discrete or continuous?
Hi Alekandro, ChunkLOD is not CLOD, it's a static paged database, which really is far less use than what the OSG provides natively with its DatabasePager with VirtualPlanetBuilder generating the databases. As for CLOD implementations, most don't scale well, don't handle geocentric databases, and most don't perform particular well in comparison to static paged databases. Personally I think CLOD is not as useful as it once was, the balance between GPU power and bandwidth/CPU power has drastically altered in the last five years, what made sense five years ago really doesn't these days. But by all means go spend time on stuff that isn't really useful... Robert. On Fri, Dec 12, 2008 at 3:39 PM, Alejandro Aguilar Sierra wrote: > Hi Robert, > > It would be interesting to implement an interactive and improved > version of ROAM or SOAR or even CLIPMAP for OSG. In vtp you can find > standalone working implementations. Both would require paged DB. The > internal representation would use different data structures. > > The only two OSG ready implementations I found at vtp was demeter and > chunked lod. > > -- A. > > On Fri, Dec 12, 2008 at 9:00 AM, Robert Osfield > wrote: >> Hi Yong, >> >> On Fri, Dec 12, 2008 at 2:53 PM, Yong Wang wrote: >>> Does OSG support continuous Level of Detail? Or support only discrete LOD? >> >> The core OSG only includes discete LOD, but it's possible to extend >> the OSG to provide CLOD. The VirtualTerrainProject has a number of >> CLOD implementations that extend the OSG. >> >> Robert. >> ___ >> 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] LOD: discrete or continuous?
Hi Robert, It would be interesting to implement an interactive and improved version of ROAM or SOAR or even CLIPMAP for OSG. In vtp you can find standalone working implementations. Both would require paged DB. The internal representation would use different data structures. The only two OSG ready implementations I found at vtp was demeter and chunked lod. -- A. On Fri, Dec 12, 2008 at 9:00 AM, Robert Osfield wrote: > Hi Yong, > > On Fri, Dec 12, 2008 at 2:53 PM, Yong Wang wrote: >> Does OSG support continuous Level of Detail? Or support only discrete LOD? > > The core OSG only includes discete LOD, but it's possible to extend > the OSG to provide CLOD. The VirtualTerrainProject has a number of > CLOD implementations that extend the OSG. > > Robert. > ___ > 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] LOD: discrete or continuous?
Hi Yong, On Fri, Dec 12, 2008 at 2:53 PM, Yong Wang wrote: > Does OSG support continuous Level of Detail? Or support only discrete LOD? The core OSG only includes discete LOD, but it's possible to extend the OSG to provide CLOD. The VirtualTerrainProject has a number of CLOD implementations that extend the OSG. Robert. ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
[osg-users] LOD: discrete or continuous?
Hi, Does OSG support continuous Level of Detail? Or support only discrete LOD? Thanks a lot, Yong ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
