cam_pos      = [-0.102843, 1.14924, -0.691752]';
cam_dir      = [-0.783638, -0.110481, 0.611314]';
cam_up       = [-0.0292383, 0.989527, 0.141353]';
cam_lookat   = [0, 0, 1]';
cam_sky      = [0, 1, 0]';
cam_right    = [0.825304, -0.123552, 1.03562]';
cam_fpoint   = [0, 0, 1]';
cam_angle    = 90;