Viewport render image -> to image w precision scale (or dwg/dxf)

I think its very helpfull to export design to cad file. Simply can do wireframe mode, set camera to ortho, click "view" (below "help"), chosee viewport render image, and I hope at least i can save the image with precision scale of actual model. Thenfore if the image is precision I can conver to dxg/dwg file on web.