How to create objects in virtual 3-D world editor?

Hello, I am learning matlab 3-D simulink toolbox and trying to create a virtual 3-D world in it.

I am using Matlab 2012a version and while creating the virtual world in virtual world editor there are some sample shapes and objects that comes default with the installation of matlab. The point i want to ask is that i want to create a hollow cylinder or a hollow sphere or a circle

Can I create the objects like i have mentioned above?? If yes, how? please let me know....

Thanks in advance