Hydroformed Lens (Mold)

Plastic/metal sheet hydroformed (bloated) mold, then cast with epoxy/plastic into a perfect solid state lens, can also be a liquid state mold contained water lens, can use transparent recycled plastic from bottles like from the sea. Inverse of vacuum forming, bloat forming, of a cold/heated plastic sheet, into a form. Can be used to make a rough metal sheet internal structure shape fast, use it as the minimal shaping guide to attach things to, like rv's or car internals, then build/weld a more rigid structure around it.