I used a ref for the light through water, but didn't really use one for the fabric. I couldn't figure out a way to get some to stay in that shape, and it shows at the bottom near the circle.>>3498204
For the fabric texture /lightinh however, I just looked up some pics of fabric suspended on the wind on google, and then applied my imagination. Thats probably why I ended up re doing it a few times. Pic related is one of the earlier iterations.