<html><head><meta http-equiv="Content-Type" content="text/html; charset=utf-8" /></head><body><p dir="ltr">Hi Renzo,<br>
Maybe a node visitor with z-near and z-far as parameter is a possible approach.<br>
Werner</p>
<br><br><div class="gmail_quote">On 15. Oktober 2020 09:46:57 MESZ, OpenSceneGraph Users <osg-users@lists.openscenegraph.org> wrote:<blockquote class="gmail_quote" style="margin: 0pt 0pt 0pt 0.8ex; border-left: 1px solid rgb(204, 204, 204); padding-left: 1ex;">
<br />
Hi Robert,<br />
<br />
<div class="moz-cite-prefix">On 14-Oct-20 3:56 PM, OpenSceneGraph
Users wrote:<br />
</div>
<blockquote type="cite" cite="mid:mailman.21167.1602683796.3540.osg-users-openscenegraph.org@lists.openscenegraph.org">
<div dir="ltr">
<div dir="ltr">Hi Renzo,<br />
</div>
<br />
<div class="gmail_quote">
<div dir="ltr" class="gmail_attr">On Wed, 14 Oct 2020 at
12:00, OpenSceneGraph Users <<a href="mailto:osg-users@lists.openscenegraph.org" moz-do-not-send="true">osg-users@lists.openscenegraph.org</a>>
wrote:<br />
</div>
<blockquote class="gmail_quote" style="margin:0px 0px 0px
0.8ex;border-left:1px solid
rgb(204,204,204);padding-left:1ex">
<div><font size="-1">I am using
osg::Drawable::getBoundingBox() to retrieve the bounding
box around the whole geometry. Is there a similar short
way to get the equivalent box for just the culled
geometry or do I need to write my own procedure?</font></div>
</blockquote>
<div><br />
</div>
<div>Culling isn't related to the nodes directly, but to a
traversersal of the scene graph that compares the bounding
shere's of internal nodes of the scene graph and the
bounding boxes of the drawable leaves. Culling can happen
at any point in the hierarchy - it can cull right up at the
top node in the scene graph if the scene is outside the view
frustum.</div>
<div><br />
</div>
<div>Within the cull traversal there is no tracking of culled
or non culling bounding boxes, a cull test is done and the
bool result used directly. There isn't a "bounding box" or
"bounding sphere" for culled or non culled objects. All the
cull traversal cares about is building a list of drawables
leaves that pass the view frustum test, there is no tracking
of any objects that are culled - this would be a crazy waste
of CPU resources.<br />
</div>
<div><br />
</div>
<div>I have to ask, why do you want a bounding box of culled
objects - what is the high level problem you are trying to
solve? It may well be that you are asking the wrong
question thinking about the task you have in the wrong way.<br />
</div>
<div><br />
</div>
<div>Robert.<br />
</div>
</div>
</div>
</blockquote>
<br />
thanks for pointing out how cull traversal operates.<br />
<br />
Yes, it might be I am searching in the wrong direction. I need to
get the minimum and the maximum Z coordinate of the geometry
vertices in order to apply a color range. This is quite easy to do
for the whole geometry but I would know if there is a way just for
the vertices inside the view frustum.<br />
<br />
Regards,<br />
Renzo<br />
<br />
<p style="margin-top: 2.5em; margin-bottom: 1em; border-bottom: 1px solid #000"></p><pre class="k9mail"><hr /><br />osg-users mailing list<br />osg-users@lists.openscenegraph.org<br /><a href="http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org">http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org</a><br /></pre></blockquote></div></body></html>