Hi Nick,
Hi Robert, Community,
I am hacking the VPB process again :-).
The story is this: I transform tiles back from ECEF to local, do
something with the Geometry and I want to replace the tile with my own
Node. Spent already hours reading and trying to understand the
SceneGraph with all this transforms, and I am failing.
Any words of how these tiles in the QuadTree are represented? I mean
the tree and the transforms, I know the facts that they are coming
from TerrainTiles with proper Locators, but after when the
GeometryTechnique is applied.
I worked it out some years ago, where I needed to capture the
transformations for a query-representation. Basically you will have a
height field-layer inside the terrain-tile, which describes itself via a
Locator and the height-values in a normalized coordinate frame. IIRC the
complete ECEF-Transform is captured inside the locator. It simply
assumes the height-field as being centered around the geographic
position when creating the world-geometry.
Some snippet to retrieve the world-coordinates of the terrain-tile's center:
<code>
osgTerrain::TerrainTile& terrain_tile =
dynamic_cast<osgTerrain::TerrainTile&>(node);
osgTerrain::HeightFieldLayer* hf_layer=
dynamic_cast<osgTerrain::HeightFieldLayer*>(terrain_tile.getElevationLayer());
osgTerrain::Locator* locator = terrain_tile.getLocator();
osg::EllipsoidModel* es = locator->getEllipsoidModel();
//compute center transform
osg::Vec3d center_model;
tile ->convertLocalToModel(osg::Vec3d(0.5,0.5,0.0), center_model);
</code>
I'm not quite sure which coordinate frame is used in the quadtree
itself, but it should be easy enough to put some subgraph to an osgt to
inspect.
Cheers
Sebastian
Thanks so much for any word on this. It is the last bump in my current dev
Cheers,
Nick
--
trajce nikolov nick
_______________________________________________
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
