Free DAZ3D Hexagon software

https://www.daz3d.com/hexagon-3d-modeling-free

Apparently supports OBJ and DXF/DWG import and export...

http://docs.daz3d.com/doku.php/public/software/hexagon/2/referenceguide/import_export/start

For Raster Imagery

Use Onshape to import and assemble models, export as .OBJ, then import into DAZ3D Hexagon as OBJ, pose and export as 

For Vector Line Drawings

Use Onshape to import and assemble models, export as .OBJ, then import into DAZ3D Hexagon as OBJ, pose and export as DXF or DWG for import into Adobe Illustrator.