t=Tachyon(xres=500, yres=500, camera_center=(2,0,0))
t.light((4,3,2),0.2,(1,1,1))
t.texture('t1',ambient=0.1,diffuse=0.9,specular=0.5,opacity=1.0,color=(1,0,0))
t.texture('t2',ambient=0.1,diffuse=0.9,specular=0.5,opacity=0.0,color=(0,1,0))
t.texture('t3',ambient=0.1,diffuse=0.9,specular=0.9,opacity=0.5,color=(0,0,1))
t.sphere((0,0.5,0),0.2,'t1')
t.sphere((0.5,0.2,0),0.2,'t2')
t.sphere((0,0,0.5),0.2,'t3')
t.show()