cam_pos      = [-0.620794, 1.33333, 0.850982]';
cam_dir      = [-0.390309, 0.169047, -0.905031]';
cam_up       = [0.881557, 0.352141, -0.314411]';
cam_lookat   = [0, 0, 1]';
cam_sky      = [0, 1, 0]';
cam_right    = [-0.353179, 1.22434, 0.381004]';
cam_fpoint   = [0, 0, 1]';
cam_angle    = 90;