Why couldn't you do this out of PVC pipe and shower curtains with rings? I might have to give it a try. adjustable canopy, DIY with shower curtain rings, grommets, canvas, PVC sprinkler pipes set over stakes.
If you have the space, make a cozy cabana to put in your back yard. First build the frame using PVC pipes. Then dig the foundation holes. Add the legs and, at the end, add the curtains. You can customize this project however you want.