cam_pos      = [-0.487169, 1.00965, 1.68874]';
cam_dir      = [0.97366, 0.207516, -0.094467]';
cam_up       = [-0.187489, 0.964457, 0.1862]';
cam_lookat   = [0, 0, 1]';
cam_sky      = [0, 1, 0]';
cam_right    = [-0.172566, 0.217567, -1.30069]';
cam_fpoint   = [0, 0, 1]';
cam_angle    = 90;