Hi Tom, osgTerrain should be able to handle height fields of much larger than 256x256, there is a code path that should be automatically selected than uses DrawElementUInt in this case, and in the past I've tested and it worked just fine. It isn't something I've tested recently though, so perhaps there has been a regression. Put some debugging code into osgTerrain::GeometryTechnique to monitor what it's doing with selecting which type of DrawElements to use.
Robert. On Sun, Jun 13, 2010 at 11:26 PM, Tom Pearce <[email protected]> wrote: > Hello community, > I've been playing around with manually creating terrain tiles (as opposed to > letting VPB do it) and noticed what to me seems like strange behavior, and I > was wondering if anyone else had noticed a similar issue - or could point > out what I'm doing wrong. I'm using osg2.8.2 on Windows 7 64-bit, stripped > down code is below. > Basically, I've been following the osgterrain example code but creating a > HeightField manually instead of loading it from a file. If I create a tile > with < ~64100 elements, everything looks fine. If I go above this (256*256, > for example), something looks like it goes wacky with how the vertices are > turned into triangles - but only the first so many of them (~64k ish), and > beyond that the terrain looks right. Either creating a viewer > programatically or saving to a .osg file and using osgviewer.exe looks the > same. > To test whether the problem is in HeightField or somewhere in the > TerrainTile, I added the heightfield to a geode - and it looked fine at all > sizes. > I realize that VPB generates 64*64 tiles, and this is a non-issue when using > tiles of that size, but I thought I'd see if there was an explanation out > there. I have looked through the forums, but may have missed something > about this issue (or feature?), so my apologies if this has been discussed > already. > Thanks, > Tom > > osg::ref_ptr<osgTerrain::TerrainTile> terrainTile = new > osgTerrain::TerrainTile; > osg::ref_ptr<osgTerrain::Locator> locator = new osgTerrain::Locator; > osg::ref_ptr<osgTerrain::ValidDataOperator> validDataOperator = new > osgTerrain::NoDataValue(-100.0); > osg::ref_ptr<osgTerrain::Layer> lastAppliedLayer; > locator->setCoordinateSystemType(osgTerrain::Locator::PROJECTED); > locator->setTransformAsExtents(-100., -100., 100., 100.); > osg::Texture::FilterMode filter = osg::Texture::LINEAR; > unsigned int layerNum = 0; > osg::ref_ptr<osg::HeightField> hf = new osg::HeightField(); > hf->allocate(254,254);//looks as expected > //hf->allocate(256,256);//funny triangles > //hf->allocate(256,512);//funny triangles over first half > hf->setOrigin(osg::Vec3(-50., -50., 0.)); > hf->setXInterval(1.0f); > hf->setYInterval(1.0f); > hf->setSkirtHeight(1.0f); > for (int c=0; c<hf->getNumColumns(); c++) > { > for (int r=0; r<hf->getNumRows(); r++) > { > if(r%20 == 0) hf->setHeight(c, r, 20.0f); > else hf->setHeight(c, r, 0.0f); > } > } > osg::ref_ptr<osgTerrain::HeightFieldLayer> hfl = new > osgTerrain::HeightFieldLayer(hf.get()); > hfl->setLocator(locator.get()); > hfl->setValidDataOperator(validDataOperator.get()); > hfl->setMagFilter(filter); > terrainTile->setElevationLayer(hfl.get()); > lastAppliedLayer = hfl.get(); > > > > _______________________________________________ > osg-users mailing list > [email protected] > http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org > > _______________________________________________ osg-users mailing list [email protected] http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
