Okay COMPLEX ...
I did say earlier, I'm using a LOGO that I designed. That's given me a little help, as I actually own the original artwork!
The first thing you are going to need is original artwork - either that, or you are going to have to trace 3D polygons in Softplan (and that can be done too if you're really desperate) ...
The chances are slim to none, that the original artwork is in a form that you can use. However, if you can obtain a PDF copy of the artwork, then we are at least at a start point - I made my own PDF from the artwork files.
Once you have the PDF then you have to OPEN it in INKSCAPE (freeware ... available here ... https://inkscape.org/en/). So open Inkscape, FILE > OPEN and select your PDF (I normally use PDF import settings as 246 VERY FINE - although I don't know what difference it makes).
Once it opens, go to FILE > SAVE AS and in the dropdown box for filetype choose AUTOCAD DXF (as shown below):
You now have an AUTOCAD DXF file that SOFTPLAN will import. SO ... go ahead and import it! ... That's ALL you need Inkscape for, but it is a handy programme to have.
FIRST THING to do now is CHECK your preferred dimension, and use EDIT > ADJUST SIZE > DISTANCE to ensure that the DXF is the correct size: Chances are really good that it's NOT!
You now have to separate all the component parts that you need, and turn them into solid polygons. Which is actually easier than it sounds. Once you have all the parts of a component, go to EDIT > BLOCK FORM POLYGON and draw a box round ALL the individual components. You DO NOT have to do them individually. Then EDIT > FORM SOLID POLYGON to change it into a solid.
Once they are done, give them a height (you can again do them ALL together with CTRL, MARQUEE SELECT and RIGHT CLICK > EDIT & REPEAT), and check that you can see them all in the 3D model.
Now from time to time, forming polygon doesn't go as per plan (okay, I'II admit it, it's a pretty regular occurance), all you can do is explode it, make sure all the lines join properly and try again ... and if you're anything like me again and again ... TIP: Arcs are the worst ... and if you need a HOLLOW circle (as you can see from the screenshot), my preference is do it in two halves and mirror them.