cam_pos      = [-0.763948, 1.09726, 0.250754]';
cam_dir      = [0.982766, -0.118153, 0.142162]';
cam_up       = [0.100085, 0.98669, 0.12816]';
cam_lookat   = [0, 0, 1]';
cam_sky      = [0, 1, 0]';
cam_right    = [0.206699, 0.148592, -1.30541]';
cam_fpoint   = [0, 0, 1]';
cam_angle    = 90;