I've been looking for something like this for a long while - but could only find expensive professional packages - photogrammetry software. Turn a photo into a CAD drawing, link: http://home.hccnet.nl/h.van.oerle/phomod/phomod.htm most CAD packages (even the free ones you can down load) will accept dxf input AFAIK, so there shouldn't be any problems. This is going to make things easier