<html>
<head>
<meta content="text/html; charset=windows-1252"
http-equiv="Content-Type">
</head>
<body bgcolor="#FFFFFF" text="#000000">
Hi Nick, <br>
<blockquote
cite="mid:CAO-+zikKGebpnsMB=_enp65Z05g=y5qFEKAeaTHSgc8fQsBuyg@mail.gmail.com"
type="cite">
<div dir="ltr">Hi Robert, Community,
<div><br>
</div>
<div>I am hacking the VPB process again :-). </div>
<div><br>
</div>
<div>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.</div>
</div>
</blockquote>
<br>
<blockquote
cite="mid:CAO-+zikKGebpnsMB=_enp65Z05g=y5qFEKAeaTHSgc8fQsBuyg@mail.gmail.com"
type="cite">
<div dir="ltr">
<div><br>
</div>
<div>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.</div>
</div>
</blockquote>
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. <br>
Some snippet to retrieve the world-coordinates of the terrain-tile's
center:<br>
<code><br>
osgTerrain::TerrainTile& terrain_tile =
dynamic_cast<osgTerrain::TerrainTile&>(node);<br>
osgTerrain::HeightFieldLayer* hf_layer=
dynamic_cast<osgTerrain::HeightFieldLayer*>(terrain_tile.getElevationLayer());<br>
osgTerrain::Locator* locator = terrain_tile.getLocator();<br>
osg::EllipsoidModel* es = locator->getEllipsoidModel();<br>
<br>
//compute center transform <br>
osg::Vec3d center_model;<br>
tile ->convertLocalToModel(osg::Vec3d(0.5,0.5,0.0),
center_model);<br>
<br>
</code><br>
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.<br>
<br>
Cheers<br>
Sebastian <br>
<blockquote
cite="mid:CAO-+zikKGebpnsMB=_enp65Z05g=y5qFEKAeaTHSgc8fQsBuyg@mail.gmail.com"
type="cite">
<div dir="ltr">
<div><br>
</div>
<div>Thanks so much for any word on this. It is the last bump in
my current dev</div>
<div><br>
</div>
<div>Cheers,</div>
<div>Nick<br clear="all">
<div><br>
</div>
-- <br>
<div class="gmail_signature" data-smartmail="gmail_signature">trajce
nikolov nick<br>
</div>
</div>
</div>
<br>
<fieldset class="mimeAttachmentHeader"></fieldset>
<br>
<pre wrap="">_______________________________________________
osg-users mailing list
<a class="moz-txt-link-abbreviated" href="mailto:osg-users@lists.openscenegraph.org">osg-users@lists.openscenegraph.org</a>
<a class="moz-txt-link-freetext" href="http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org">http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org</a>
</pre>
</blockquote>
<br>
</body>
</html>