cam_pos      = [-0.55728, 1.05037, 0.756952]';
cam_dir      = [-0.433192, 0.395187, -0.810044]';
cam_up       = [0.896205, 0.284309, -0.340566]';
cam_lookat   = [0, 0, 1]';
cam_sky      = [0, 1, 0]';
cam_right    = [-0.127301, 1.16175, 0.634848]';
cam_fpoint   = [0, 0, 1]';
cam_angle    = 90;