cam_pos      = [-0.639081, 1.39441, 0.29012]';
cam_dir      = [0.632634, 0.0695107, 0.771325]';
cam_up       = [0.542004, 0.671662, -0.505076]';
cam_lookat   = [0, 0, 1]';
cam_sky      = [0, 1, 0]';
cam_right    = [0.735727, -0.980995, -0.515031]';
cam_fpoint   = [0, 0, 1]';
cam_angle    = 90;