Re: [osg-users] VirtualPlanetBuilder and pagedLOD chalenges my Targeting pod camera
Hi Ralf, VPB couples terrain with imagery storing them in exactly the same .ive tiles. Normarily one shouldn't have to tweak --radius-to-max-visible-distance-ratio, performance should be good without any tweaks, and should scale to terabyte databases. I found it pretty hard parsing your email thanks to all the acronyms so am not entirely clear on what your hardware set up. It may be that Delta3D is part of the problem, try building the VPB database and viewing using osgviewer to see if there is performance delta. Use of Windows for a visual simulator is not something I would recommend, the file system performance sucks big time, memory management and threading support is not great either. Install a modern Linux and you'll probably find many of your issues gone. I'd also recommend an upgrade to OSG-2.4 as the DatabasePager has been improved w.r.t load balancing, keeping memory consumption much more even. OSG-2.4 also offers improvement to osgTerrain, such that one can now control the sample density of elevation data via the osgTerrain::Terrain class, to generate such databases you'll need to build using SVN version of VPB and use the --terrain option. Robert. On Fri, May 16, 2008 at 8:44 AM, Ralf Stokholm [EMAIL PROTECTED] wrote: Hi Im working on a flight simulator project and have been using VTP to generate a terrain for visualisation, The input data is 30m landsat orthofoto and 90 m nasa elevation data. In addition there are som higher resolution orthofoto for specifik target areaes dovn to 25 cm resolution. My application has a Targeting POD displaying in the cockpit in adition to the standart otw view, the problem is that I have a hard time getting it to run smothly. To keep good quality in the TGP view I had to increase the --radius-to-max-visible-distance-ratio from default 7 to 25 in order to get the orthophoto to load early enough in my zoomed targeting pod view. I I generate the terrain without height date it almost runs smooth at that setting, but with elevation data it studders all the time. Especially when turning my head. Im using the delta 3d engine and the allocate 4ms for paging opperations each frame. This is tested on a brand new system Core2 duo 3.0 Ghz 4 Gb RAM and a geforce 9800 GTX, it has a raid0 hard drive etc so I cant emagine this it the limiting factor. Oh its running windowsXP sry :( OSG is verison 2.2.0 and VTP is version 0.9.1 The aplication is rendered on 2 displays a 1920x1200 display for the cockpit TGP view is roughly 512x512 ans a 1920x1080 display for external view. The following is the command line used for generating the terrain archive. osgdem -d height -t texture -l 20 --radius-to-max-visible-distance-ratio 25 -v 1.1 --cs +proj=laea +lat_0=55.5 +lon_0=9.5 +x_0=0 +y_0=0 +datum=WGS84 +units=m +no_defs -o denmark.ive -a denmark.osga Is there any way of making the terrain load later in the OTW view? Or any other hints on what parameters to play around with to improve the performace of this? Brgs Ralf Stokholm ___ 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] VirtualPlanetBuilder and pagedLOD chalenges my Targeting pod camera
Hi Ralf, On Fri, May 16, 2008 at 10:06 AM, Ralf Stokholm [EMAIL PROTECTED] wrote: It sounds like I should defenatly try running it on a linux box, it will be quite a challenge though, havent spend much time with linux :( These days Linux is pretty slick as a development platform. It takes me just half another to install Linux, and all the development tools and sources required to build the OSG, this is from a blank disk to a work dev environment. Immediately I just use nedit as an editor, cmake/gmake for build, and gdb for occasional debug session so I have no IDE to install, but there are IDE's available, and it'll just be another item to click to install on modern installers. If you aren't familiar with Linux then it'll take you while to get up to speed, but once you are I'd expect you'd find it pretty productive. For a vis-sim runtime it's certainly one of the best platforms available. With cross platform tools like Delta3D and OSG you can even dev on one platform and reploy on another. The reason I have to tweak the --radius-to-max-visible-distance-ratio variable is that one of my cameras are rendering for a Targeting Pod (One of those aiming devices for laser guided bombs that you see on Discovery) This camera has the ability to zoom in on the target arear vith i.e. a 1.5 degree field of view, this results in visual artifacts ( texture popping) because a given lod is simply visible from farther away. What you you use is LODScale instead, this way you can adjust things according the display you use without needing to tweak the database. viewer.getCamera()-setLODScale(scale); // 1.0 is default Robert. ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
Re: [osg-users] VirtualPlanetBuilder and pagedLOD chalenges my Targeting pod camera
Hi Robert Thx a lot for the swift answer. and sry for the acronyms. Im working on testing it on osg 2.4 and the SVN version of VTP. Will know more in a few days ( I hope) It sounds like I should defenatly try running it on a linux box, it will be quite a challenge though, havent spend much time with linux :( The reason I have to tweak the *--radius-to-max-visible-distance-ratio *variable is that one of my cameras are rendering for a Targeting Pod (One of those aiming devices for laser guided bombs that you see on Discovery) This camera has the ability to zoom in on the target arear vith i.e. a 1.5 degree field of view, this results in visual artifacts ( texture popping) because a given lod is simply visible from farther away. If i increase the *--radius-to-max-visible-distance-ratio *my normal out the vindow view, which is rendered on a second screen using the same data will load the same lods roughly 3 times too early. This camera uses a more normal 60 degree field of view, and wont have to load the lods at the same time. I have testet the database in osgViewer and it seams to run smoother, but if i set up the view to rotate cose to ground so the data rendered at any given time will change fast i still get studders/framedrops. Brgs. Ralf ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
