cam_pos      = [0.218594, 0.632288, -0.319551]';
cam_dir      = [0.871148, 0.314053, 0.377455]';
cam_up       = [-0.476263, 0.353384, 0.805167]';
cam_lookat   = [0, 0, 1]';
cam_sky      = [0, 1, 0]';
cam_right    = [-0.158907, 1.17198, -0.60837]';
cam_fpoint   = [0, 0, 1]';
cam_angle    = 90;