I used the 2d-3d "wizard" to load and convert to 3d, a 2d drawing. As input i used a high quality png bitmap. My question is, what size will i get. I want to get the exact same size of the cad file before the export to bitmap. When uploading there is a size field and slider but i didn't understand what it controls... Any hints ?
It depends on the design. If design it is complex then you better ask a designer to have a look and tell you if it can be done better. From what I see on the 2D-3D app , the thickness it is the overall thickness and the second slider it is the measure from first to longest point of the object. If you really want something with exact measures and have a pendant and such with some exact measures then better contact a designer to make it on that measures. That app it is for things not "exact" rather approximated measures ... think like a "keychain" , "big pendant with not fine defined design" kinda of things.