README.md

new mechanism to add texture to volumes based on material name. For the moment, volumes using a 'GeoModelDummyMaterial' is rendered with a yellow-striped 'under construction' texture. But the mechanism is now in place to add textures based on any material name. The new feature required changes to the basic shape SoGenericBox, inheriting from SoShape. In particular, it required the definition of texture coordinates for this custom shape and the ridefinition of the SoShape::GLRender method. One caveat: with this modification the VP1/Explorer 'show outlines' feature does not work anymore; but it works if I use the default SoShape::GLRender() method, so something needs to be changed in my new GLRender method.