cam_pos      = [0.638474, 1.60344, 0.286331]';
cam_dir      = [-0.774702, -0.477356, -0.41469]';
cam_up       = [-0.216237, 0.816275, -0.535664]';
cam_lookat   = [0, 0, 1]';
cam_sky      = [0, 1, 0]';
cam_right    = [-0.790291, 0.432661, 0.978337]';
cam_fpoint   = [0, 0, 1]';
cam_angle    = 90;