cam_pos      = [0.460731, 0.606491, -0.146407]';
cam_dir      = [0.845883, 0.376806, 0.37749]';
cam_up       = [-0.522679, 0.444626, 0.727403]';
cam_lookat   = [0, 0, 1]';
cam_sky      = [0, 1, 0]';
cam_right    = [-0.14131, 1.08076, -0.762157]';
cam_fpoint   = [0, 0, 1]';
cam_angle    = 90;