Hello, yes it's possible to create objects but i think it's a bit difficult :
http://www.thesimsresource.com/resources/view/category/creating-sims3-meshing/id/90/
http://www.thesimsresource.com/workshop
http://www.google.fr/search?sourceid=chrome&ie=UTF-8&q=create+an+objetcs+#sclient=psy-ab&hl=fr&source=hp&q=create+an+objects+sims+3&pbx=1&oq=create+an+objects+sims+3&aq=f&aqi=&aql=&gs_sm=e&gs_upl=27142l29314l0l29566l7l7l0l0l0l0l230l1282l1.3.3l7l0&bav=on.2,or.r_gc.r_pw.,cf.osb&fp=79f5663e5c60692e&biw=1920&bih=1085
But just one question: why are your others topics in french ?