Want to build an inflatable dome. Already have a working design but there is a catch, it inflates the inside of the dome, I want to inflate the walls of the dome instead. PVC sheets used btw, welded together with heat gun and solder iron with custom tip. There are commercial seller but boy are they expensive for a non profit user. Plus I have specific requirements such as inside walls being smooth flat and having bulges on the outside. I have some working design for pillows and such but the issue with a complex shape such as dome is harder way to get to its shape, make sure it doesnt collapse from its own weight. The program I use is ExactFlat, monthy subscription so far, dont have spare 6 grand laying around. Any tips would be appreciated, be it whether ExactFlat can take care of all this and how, other software that wont destroy my wallet or just non software based advice.