Hi Andrew,

On 7/5/06, Andrew Weitz <[EMAIL PROTECTED]> wrote:
Thank you for the advice!  I actually am using a scheme almost identical
to the one you mentioned.  The only differences are that I'm using
PagedLODs, I'm using display lists (in addition to VBOs), and I have
matrix transforms that are applied to the geometries.  I'll try going
without the PagedLODs and seeing what happens.  If you don't mind, I'd
like to clarify a couple things before proceeding:

If you enable VBO's and Display lists all you'll get is VBO's, if they
are supported.


1. When you say spatially segmented, I'm assuming you mean that the
points in each osg::Geometry should be close in proximity.  But do you
also mean that the scene graph should be organized spatially in a quad-
or oct-tree structure of osg::Groups?

An oct-tree would be typically for a regular box shaped data, if its
flat then quad tree would be more appropriate.  osg::Groups and
osg::Geode would help form this oct-rree.

The leaves on the oct-tree will be your osg::Geometry, each of which
has a maximum number of vertices.

PagedLOD only makes sense if you can LOD the data, which is an
interesting issue with point clouds.  How best create LODs?  One
property of LOD's in the OSG is that the ranges can overlap so two LOD
children can be one at once, so you can in sequence add layers of
points to keep up the number of vertices, this way you wouldn't ever
have to repear any vertices.

2. I have some datasets with over 100 million points, so I'll need to
use PagedLODs at some point.  When you say that the DatabasePager should
be set up to achieve a variable frame rate, do you mean that I should
call setUseFrameBlock(false)?

No, I'm thinking of

 osgDB::DatabasePager::instance()->setDoPreCompile(false);

Robert.
_______________________________________________
osg-users mailing list
[email protected]
http://openscenegraph.net/mailman/listinfo/osg-users
http://www.openscenegraph.org/

Reply via email to