cylinder Gives methods to draw cylinders as OpenGl objects pairing two elements. The cylinders have two characteristics : their radius and their colour. Their radius are in the units of the rendered box. They can be specific to each kind of pairs (e.g. Si-Si) or they have a default value. Only the default value is stored in the resource file with the flag "pairCylinder_radius". Their color is herited by the the colour of the pair. The lighting values (i.e. emi., shi., spe. ...) are not movable and are fixed to amb = 0.5, dif = 0.5, shi = 0, spe = 0, emi = 0. @Returns: @val: @Returns: @Returns: @data: @val: @Returns: @data: @Returns: @val: @Returns: @Returns: