cam_pos      = [0.64477, 1.44409, 1.32335]';
cam_dir      = [-0.804936, -0.027907, 0.592705]';
cam_up       = [-0.236624, 0.931127, -0.277511]';
cam_lookat   = [0, 0, 1]';
cam_sky      = [0, 1, 0]';
cam_right    = [0.723705, 0.483624, 1.00561]';
cam_fpoint   = [0, 0, 1]';
cam_angle    = 90;