Cloth simulation staying in plane I'm working on a bathroom interior, and I was trying to shape the shower curtain by following this tutorial:
Modeling with Cloth Simulation in Blender

For some reason, after I selected the pinned verticies group, and ran the simulation, the cloth was affected by the pinned verticies, and also sagged, but all the movement was done in one plane, so there were no wrinkles.  How can I fix this?  Here is an image of one of my tests so you can see what is happening:



Here are my Physics Settings (As far as I know, they are the same as what he has, and also, I have animated shape keys so that the cloth would fold).



Here is the .blend:
https://drive.google.com/file/d/0B5Rj7h_MP4waeU5yc3ZyV0VZQlU/view?usp=sharing
The problem was that I was trying to do a cloth simulation inside a scene with several objects already inside.  Many people had the same problem in the comments on this video:

Modeling with Cloth Simulation in Blender

The trick was to do the cloth sim in a different scene and then import the mesh into the scene you want to use it in.