Technology pushes forward into the early 3D days where parametric tools were not standard yet and the list of CAD platforms expands, bringing even more file formats into the game. Being a long time user of CADKey, the best 3D wireframe modeler of it’s time ;-), featureless 3D modeling was useful but time consuming and allowing the capability of viewing or sharing of this data needed a format standard. In those days I was using formats like ACIS, IGES (or “I Guess”) and STEP to name a few. These formats were read by many CAD platforms and would facilitate your typical fit, form and function requirements. These were featureless models but so were the CAD tools used to create them so the translated geometry was essentially the same as the original.