cam_pos      = [-0.574042, 1.27477, 0.214526]';
cam_dir      = [-0.520454, 0.16702, -0.837396]';
cam_up       = [0.848442, 0.211749, -0.485086]';
cam_lookat   = [0, 0, 1]';
cam_sky      = [0, 1, 0]';
cam_right    = [-0.128077, 1.28072, 0.335043]';
cam_fpoint   = [0, 0, 1]';
cam_angle    = 90;