cam_pos      = [-0.526554, 1.31894, 0.30879]';
cam_dir      = [-0.603805, 0.156837, -0.781551]';
cam_up       = [0.790063, 0.248037, -0.560606]';
cam_lookat   = [0, 0, 1]';
cam_sky      = [0, 1, 0]';
cam_right    = [-0.140887, 1.27144, 0.36399]';
cam_fpoint   = [0, 0, 1]';
cam_angle    = 90;