How to force creases into a cloth object? I want to be able to simulate a cloth object where some of the edges want to crease to some angle. For example, this mesh below has a line of edges marked seam on the left, and on the right I've used edge crease to highly another line of edges.



And I want to be able to tell Blender that the seam marked edges should be bent to 90 degrees, and the creased edges to be bent to -90 degrees, which the following picture illustrates.

Thanks!



I tried to do this once years ago using a sort of genetic algorithm sort of approach, and shape keys, with mixed results, then last night a friend suggested I try cloth simulation, which seems much more promising.

I don't care if the solution has anything to do with seams or creasing, just so long as I can have Blender know it should bend part of a cloth object to some angle.

Edit: I want the physics simulator to do the bending for me, so for example, I would make the original flat mesh, and add something so it would know the edges should be creased to some angle, and then the simulator itself would do the bending for me along the edges as I've defined, to the pre-defined angle.

A Second Edit: What I'm trying to simulate is the way paper folds, as in this video here: https://www.youtube.com/watch?v=2Q-A38tK4SA
The video depicts the result of folding concentric squares into a square piece of paper, which causes it to turn into a saddle, or potato chip shape. I can rig up bones to bend the "paper" model in Blender, but I want Blender to actually do the saddle-shape deformation, based on the fact that the model is creasing.

This is a rigged plane:



And notice it doesn't reproduce the saddle shape. I think it would be area preserving that would mimic paper, since paper can't stretch or shrink, but I don't think volume preservation will work right.
You should probably use pinning for this. If I understand correctly what you want vertex groups will allow you to define parts of the mesh not altered by the cloth simulation.

Select a few corner vertex, as many as you need, the more selected vertex the stiffer the animation will be, and assign them to a new Vertex Group.



Use that vertex group for pinning under the Physics > Cloth > Pinning.
You can use this in conjunction with shape keys and animation to drive the shape from flat to folder or similar.