[osg-users] Geode, Geometry, glCallList, glMultMatrix and so on :)

Quanteek osgforum at tevs.eu
Sun Mar 15 03:33:57 PDT 2009


Hey Robert,

You're right.

So my application is a plant generator.

A plant is composed by elementary units called "metamers". A metamer is a container which has an internode (typically a cylinder for trees for making the branches) and a leaf (well, a leaf like in real life :p).

In input of my software I have got a big graph (tree) of bases (so direction and origins) and also what I call a pattern file which has the basic shape for an internode or a leaf.

Typically I load my pattern file into an osg::Geometry.

Thanks to theses bases I compute all basic geometries into all theses bases.

For example if my axe has 10 internodes I will have :

10;9;8;7;6;5;4;3;2;1

and each number is a cylinder and each of them would be an osg::Geometry. Here you see that if my tree is about 200 axes it could be very heavy in term of memory.

Same thing for the leaves if I have got 1000 of them into my tree I will have 1000 osg::Geometry into one geode.

So my osg graph is for the moment composed by two osg::Geode one for axes and one for leaves because Material will change between them.

My main problem is the export into Collada file with DAE plugin(for the moment performance is acceptable but I think VBO could be a great thing but didn't think about it now). The file is for a little tree about 15 Mo and I cannot import it into Blender or Swirl.

So I am wondering where I am wrong. For the moment I have all geometry which is explicit. All entities have been calculated into its place and store into an osg::Geometry. Apparently you are not recommanding to use MatrixTransform and call an unique osg::Geometry (the pattern) ?
Does the trick with "chunck of geometries" is dumping a whole axe into one osg::Geometry (with the example upon it would be 10;9;8;7;6;5;4;3;2;1 a single osg::Geometry) ?
-- 
Benoît Bayol
benoit.bayol at gmail.com

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-- 
Benoît Bayol
benoit.bayol at gmail.com

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http://forum.openscenegraph.org/viewtopic.php?p=8496#8496








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