CAD Data Quality

CAD data quality assessment and definition are not trivial issues. The first question one can ask "what is the CAD data quality and how can we define criteria telling us that a given model can be considers as quality CAD model and other not? One can use two types of quality criteria: international standards (SASIG, VDA, JAMA, etc.) or process define (driven) criteria.

The international standards describe in details definition and tolerances for all different 3D model entities. So checking a model against a set of those definitions will answer the question "what is the 3D model quality". If we pass all of them we have a high quality 3D model. This model will most probably not create any interoperability issues, when transferred to other CAD/CAM/CMM system as the internal definition is flawless. Models not meeting quality criteria will cause interoperability issues.

Another way on looking on the quality definition is using a specific process we submit our 3D model to. Let's consider manufacturing as an example. We know at our manufacturing capability is limited to producing 3 mm radius as the smallest possible rounding. This limitation can driven/define the quality requirements on the 3D model. We will consider any model with rounding equal to 3 mm or more as quality model (we can manufacture it) and models with rounding smaller than 3 mm as not quality models. This is simple example explains how the quality can be driven (imposed) by the process parameters.

The other important aspect of quality assessment process is environment (system) used for checking the quality. In case we do it in a given CAD system (e.g. CATIA) we become dependent on the representation, in this case CATIA, internal representation of the model entities defining a 3D model. The quality may by OK within CATIA environment, which does not imply that it will stay the same once the model is exported to other CAD/CAM/CMM system. The correct quality check should be performed in an independent system like 3D TransVidia based on exact geometric kernel (3D TransVidia kernel uses exact representation for model entities and maintains data structures used by most CAD systems – no change in the entity definition when imported into 3D TransVidia kernel). This unique capability allows us to perform neutral and independent 3D model quality assessment.

Capvidia PDQ product line supports all industry standards such as SASIG, VDA, JAMA, and allows users to define their own/process driven quality standard. Capvidia's proprietary exact geometry kernel ensuring CAD independent (external audit) model quality verification.

Capvidia PDQ solutions are available in the following products:

  • 3DTransVidia – precise CAD data translation application (desktop/server)
  • QVidia – standalone application (desktop/server)
  • PDQWorks – add-in for SolidWorks
  • A set of libraries (.dll) with documented and easy to integrate API