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I'm not too sure if this can be considered a bug or if it's just how it's meant to be.
If I add billboard nodes in my scene, they disapear when hidden by a wall or something. If I add ITextSceneNodes, I would expect them to do the same thing (but they don't...). Is there a possible 'hack' for this (I know there is a setVisible(bool)...)
The problem is that they are simply drawn as text after all other nodes, as 2D elements. No 3d drawing. There is no work around for this currently, sorry.
GUI is 2d in front of all 3d ...
what you want is meybe render to texture or somethink ... make a simple small wall withe the texture if you don't want dinamic text ... or use more textures for the node if you want dinamic ...