[color=#0000ff][i]note[/i][/color]: you can directly open this material in [i]GeoGebra 3D Graphing[/i] just clicking in [br][u][url=https://www.geogebra.org/3d/McFSQ6CZ]https://www.geogebra.org/3d/McFSQ6CZ[/url][/u]