I don't understand how it's different from using the lights. Why would you need to rerender everything?

From what I understand altframes (ie Leviathan) must display sequentially as if an animation. Having the damaged frames alternate with the not so damaged frames seems a bit counterproductive. Anyway all signs are pointing to this not really working, so nevermind, but thanks for all the help everyone

rmx, see my post. AltFrames are a set of sprites overlayed on the ship; what you are thinking of, as I said, is using the base sprite set for animations. Again, for an example of a behavior similar to what you want, see the Thunderforge.