I understand, but thats the way it has to be. Try assigning the "mtl_levelDefault" material to all of the blocks, they'll then render to the view. You have to remember that Shade-C is still in its infancy, and an easier solution may come to pass later. But at this time, thats the only way unless you already have shaders you wish to add to the Shade-C render chain which is a whole other can of worms in itself.