cam_pos      = [-0.331117, 0.948176, 0.647213]';
cam_dir      = [-0.582511, 0.447224, -0.678728]';
cam_up       = [0.812769, 0.330076, -0.480058]';
cam_lookat   = [0, 0, 1]';
cam_sky      = [0, 1, 0]';
cam_right    = [-0.0124203, 1.10561, 0.739165]';
cam_fpoint   = [0, 0, 1]';
cam_angle    = 90;