Not quite clear what exactly you are asking but I will try to answer.
If you need simple geometry like boxes, pyramids etc. And it must be interactive you can implement it with:
SVG: http://code.google.com/p/svg3d/ - slowest and may not work everywhere.
CSS3: http://jlongster.com/s/dom3d/ - a bit faster and in some browsers GPU accelerated but will not work in old browsers.
If you need more speed or complex shapes then you should use Flash or WebGL. But 3D apis are complex and aren't cross-platform or cross-browser at this time. In this regards Flash is better choise but only at this moment.
So for you http://www.x3dom.org/ could be the best choise. It's 3D engine that doesn't require programing skills nor 3d api knowledge, it has both Flash and WebGL mode + it's very easy to learn.
But if you need only static images you may render them server-side based on user request(data from form) You can cache them. You can make them as pretty as you want. And in the same time they will be maximally compatible with any platform. You can setup your own server or use render farm like this