How do they create the "wrinkle" effect for this with different shapes?
@sethzhao506 In project 4 you will actually write code to simulated the wrinkling of cloth.
The difference in shape originates from the rigidness of the material. In the project, this is controlled by the stiffness of springs.
The difference could also be affected by the density of the cloth material, as we would expect a cloth made of denser material to fall lower from its pinned points.