cam_pos      = [-0.427985, 0.878507, 1.6145]';
cam_dir      = [0.880245, 0.464294, -0.0979795]';
cam_up       = [-0.412953, 0.851242, 0.323818]';
cam_lookat   = [0, 0, 1]';
cam_sky      = [0, 1, 0]';
cam_right    = [-0.310889, 0.325289, -1.25157]';
cam_fpoint   = [0, 0, 1]';
cam_angle    = 90;