cam_pos      = [0.698379, 1.64486, 0.327699]';
cam_dir      = [-0.580513, -0.46714, -0.666922]';
cam_up       = [-0.117136, 0.858453, -0.499337]';
cam_lookat   = [0, 0, 1]';
cam_sky      = [0, 1, 0]';
cam_right    = [-1.07169, 0.281629, 0.735571]';
cam_fpoint   = [0, 0, 1]';
cam_angle    = 90;