I have two friends that want to create a jewelry store, focused on customised jewels.

The core feature is the jewelry generator, based on a jewel model, like: http://www.gemvara.com/jewelry/wisteria-pendant/pear-citrine-18k-yellow-gold-pendant-with-diamond/155hhg

Any one has any idea or experience about how generate all those kinds of customizations dynamically?

Thanks.

P.S.: I was searching about gemvara solution and it's use dynamically product images. Because my first hypothesis was their were real pictures.