Unfortunately, because of the complex shape of this visor, if you want it to be able to see out of it, and have it be seamless, it's goingto have to be vacuum formed. Making a vacuum forming machine isnt too difficult, but may not be worth the time and money if you are only going to use it once or twice. Alternatively, your best bet is trying to find a local makerspace that has one, or reaching out to purchase an already done visor. Finding one that will perfectly fit you helmet and not the one it was originally designed for may be a challenge