There was discussion from 2 years ago which, I think, sort-of covers this question, but I have trouble understanding the content of the discussion and anyway we’re on KiCAD 5 now-- maybe things have changed?
Basically, I would like to render my PCB along with another mechanical assembly. The goal is to show the PCB in the context of it’s usage-- mounted to a product with some standoffs. I can get step files of the other assemblies and view them in FreeCAD, I can get other formats too. Don’t care about image quality or photorealistic rendering, just need this for documentation.
Is there a straight-forward way to do either of these things…
Export my PCB into some cad file format so that I can compose it with other 3D models?
Import a 3D model, somehow position it relative to the PCB and render the whole thing in the KiCAD 3D viewer?
It is possible now with KiCad 5 to import STEP files directly.
You still need a footprint to import the 3D shape into. eg: you can create a void footprint (with just assembly draws) and add the 3D STEP shape to it. TIP: you can choose the footprint to be a virtual property so you can hide/show it by pressing V in 3D Viewer.
Adding external models into footprints is an intersting possibility, if you don’t know how to use a CAD application, the model is easier to align with KiCad than to learn another application. Otherwise you can also export the board as STEP model, it’s in pcbnew’s File->Export.
I was able to import some step files, like for stand-offs, but I am having trouble with one.
It displays itself fine in the footprint editor when I add it as a 3D model, I can even position it correctly, but then gives an error about invalid chars in the step file, after I click “OK” in the footprint properties dialog. Comparing it to other step files, it doesn’t seem to have bad chars. Kind of strange that it says that ONE of a list of invalid chars was found, but it doesn’t indicate which one.
When I try opening it in FreeCAD, saving to FreeCAD native format, opening and exporting to STEP, it still gives the same error. Even tried opening the IGES format in FreeCAD and exporting to STEP-- still same error.