Sorry about the tilte but I'm truly frustrated since I've seen hell trying to get a cloth simulation demo to work with JWS.
The demo works just fine on my pc, and yet when I attempt running it through JWS, it gives me a blank screen.
After MANY hours of debugging, it turned to be that adding a LightPoint prevents the demo from running.
Here's the JWS link
And here's the source
To have the demo working as a JWS application, for now I set up material.setLightingEnable in ClothFactory to false for both piece of clothing and the sphere, and took off the part where I add the point of light in the scene() function in ClothSimulation.
Here's what the application looks like ran on my pc
PS: use 1,2,3,4 to control the cloth four corners and space to reset the demo.