I have a mesh that already uv mapped, and finished all other stuffs like texturing etc. Note that I always do unwrap every mesh in same material so that they have same scale as well.
But I just realized that I forgot "something" in my model, so I just made it and put in the mesh. The problem is that there's no way to keep my previous uv coordinates remain and only unwrap my new mesh with same scale to others. I can manually scale down until it has similar looking, but it's not precise.
How do I keep my previous uv works not change, only add new uv islands with same scale?