OpenSceneGraph 3.0

Chapter 5

Fast dynamic casting

The asGroup() and asGeode() methods are virtual methods that could be re-implemented by subclasses such as osg::Group and osg::Geode. These methods actually don't do any runtime check and simply return NULL if not overridden, so they are always faster than dynamic_cast<>. The limitation here is that they only convert nodes into specify types, so if you are going to cast a certain node pointer to the osg::LOD type, use dynamic_cast<> instead:

osg::LOD* lod = dynamic_cast<osg::LOD*>(node);

Matrix multiplications

There is a website that excellently introduces the concepts here, as well as explains the reason why OSG does not use the column major and prefix notations that are introduced in OpenGL books: http://www.openscenegraph.org/projects/osg/wiki/Support/Maths/MatrixTransformations ...