cam_pos      = [-0.136404, 1.55578, 0.835135]';
cam_dir      = [-0.901261, 0.111518, 0.418679]';
cam_up       = [-0.262932, 0.627272, -0.733074]';
cam_lookat   = [0, 0, 1]';
cam_sky      = [0, 1, 0]';
cam_right    = [0.45802, 1.02513, 0.712899]';
cam_fpoint   = [0, 0, 1]';
cam_angle    = 90;