[3] There are at least three ways to exchange data between different CAD system: via a hardcopy or image (e.g. TIFF, GIF, JPEG, BMP or PCX, by way of image tracing), CAD-neutral formats or third-party CAD file translators between proprietary file formats.
The structure of the neutral database must be general, governed by the minimum required definitions of any of the modelling data types, and be independent of any vendor format.
[5] This option is limited by the fact that most CAD formats are proprietary therefore direct translators are typically unidirectional, partially functional and not standardized.
There are a handful of companies that provide low-level software toolkits to directly read and write the major CAD file formats.
[3] The intermediate file formats are also limited in what they can describe, and they can be interpreted differently by both the sending and receiving systems.
No matter what data is to be translated, there is also a need to preserve attributes (such as color and layer of graphical objects) and metadata stored within the files.
Old neutral formats like IGES can have some translation issues[15] like loss of the original color of the parts, or incorrect position of bodies.
Validation Properties are key characteristics of the model (Center of Gravity of a solid, wet area of a surface, PMI characteristics or even check points on a shape), stored by the emitting system and checked by the receiving system.
For instance, the component LEDAS Geometry Comparison based on C3D kernel can be integrated in CAD system (like Autodesk Inventor,[18]) to compare 3D models and pinpoint all of the differences between them.
The other is the increased reliance on digital mockups to permit visualization, design in context, simulation and analysis of large scale assemblies prior to the actual manufacture of the physical product.
The ability to visualize medium if not large scale assemblies was one of the early successes of these CAD translation formats.
Current advances now allow an “Active Mockup.” This technology allows design in context with simulations such as dynamic clearance analysis and automatic generation of motion envelopes.
[citation needed] NC programming typically requires that the geometry received from a CAD system, whether in wireframe, surface, solid or combined formats, be free from any irregularities and inconsistencies that may have occurred in the CAD phase of geometry creation.
In a true PLM environment, CAD to CAM data exchange must provide for more than the transfer of geometry.