why not have a zone where you can actually create things and view them in 3d. you can drag and drop from thousands of parts. and others can view your creation in 3d ,not just an image!
hi ! i'm nina ! ur idea was intresting with which language do u want to write this program !!! ( i study computer ... i sugest c++ )
but this may have some problems ...! in that way every body show now computer to ... use ur software ... !!! ( or may be i did;nt understand ur idea) :) good luck !