Hi Robert I've had a look at OSG's databases. I'm extracting 2D slices from a 3D database. I can't change the data storage method used for the 3D data, and I want to avoid any preparation stage that would require duplicating all the data in another format.
Once I've extracted a 2D slice I need to store it in another internal format so that it can be accessed by other programs. For those reasons I don't think the OSG's databases will work for me. >From what I understand any OpenGL texture has to be entirely within GPU memory if it is accessed at all, so I think I can cut my usage of GPU memory a lot by breaking up the textures - then occluded textures won't be paged in. Do you know of any examples of how to do this within osg? Thanks for your help. Cheers Grahame On Mon, Sep 20, 2010 at 11:01:10AM +0100, Robert Osfield wrote: > Hi Grahame, > > Are you aware of VirtualPlanetBuilder and osgEarth? They both provide > support for taxing high res imagery and generating OSG databases from > them. VirtualPlanetBuilder is an offline too, while osgEarth can do > it at runtime. > > Robert. > > On Mon, Sep 20, 2010 at 7:14 AM, Grahame Bowland > <grah...@fugro-fsi.com.au> wrote: > > Hi all > > > > I'm wondering if anyone could give me some advice - I'm working on a 3D > > viewer application that makes use of OpenSceneGraph. At the moment I'm > > loading large 2D slices of data into textures, and then using a fragment > > shader to colourise them. > > > > The slices of data are big (up to 150MB), and consist of 32-bit floating > > point data. I'd like to split the hunks of data up to reduce the amount > > of data being paged into the video card when a frame is rendered. I'm > > wondering what the best approach might be. > > > > At the moment I've got a single osg::Geometry created by > > osg::createTexturedQuadGeometry(). I initially thought I could keep this > > single geometry and just pass multiple textures through to my shader > > program, but it seems that sampler2DArray isn't supported on all the > > cards I need to support. > > > > I'm currently thinking of using multiple geometries for say 512x512 > > sized textures of my data, and overlapping them to avoid interpolation > > issues on the boundaries. I'm worried about seams appearing and other > > artifacts though, so I thought I'd ask the mailing list for advice > > before writing too much code! > > > > Thanks for any help, > > > > Cheers > > Grahame > > > > _______________________________________________ > > 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
