Testing curved folding

No, this isn't the desert at night this is a part of a curved fold I made to see how it works, this one one with a bit wrong exposure setting, but gave a pretty cool look. I am very fascinated by allot of origami artist who managed to make curved folds in their design. However I haven't found any tutorial or any books that explain in which way you can calculate the shapes of these kind of folds and what happens. Because most plain folds that are flat with hard edges can be calculated fairly easily, but these curves are quite a mystery for me.
However I did learned few things by just trying to make simple rounded folds. Actually they are not that hard to fold but just don't know what they would do. But on some parts they are still same to normal origami, however I think I need to buy a cutting plotter which has a pen holder to scorch the fold lines for me, otherwise I need to draw all those round lines myself. I am thinking of several things I could implement this because it looks so odd but very cool.