Data Repair

Delcam has launched the Solid Doctor for the repair of CAD models as part of the new releases of its PowerSHAPE CAD software and the CopyCAD Pro reverse engineering program. Both programs now incorporate Parasolid^® software, the industry-leading geometric modelling component from Siemens PLM Software. The addition of Parasolid, together with Delcam’s existing tools, allows the Solid Doctor to read in and repair models from all sources, including IGES and native CATIA files, and output a Parasolid XT file that can be read directly into all software based on Parasolid, including IronCAD, SolidWorks, TopSolid, T-Flex and VisiCAD, as well as Siemens PLM Software’s own Solid Edge^® software and NX^TM software products.

To read more about the costs of data transfer and learn how Solid Doctor can help solve these problems, download the white paper from http://www.delcam.tv/PS2010/Downloads/PowerSHAPE2010.pdf. A video showing how the Solid Doctor works can be viewed at www.delcam.tv/soliddoctor.

The Solid Doctor is a major step towards true interoperability with many popular CAD systems. Parasolid is the component modelling engine on which more CAD systems are based than any other, while others such as Autodesk’s Inventor and PTC’s Pro/Engineer, have import/export filters for the Parasolid native XT file format. As such, once a valid Parasolid model has been created, these systems can exchange the data without translation and the inherent further re-work such translation entails.

With the Solid Doctor, users will be able to tackle all the common problems that can be found when translating low precision and incomplete data, including gaps and overlaps between surfaces, or duplicated and missing surfaces, and generate a valid, high-precision Parasolid model.

The Solid Doctor uses the automatic data repair tools that are provided as part of Parasolid, together with the surface creation and editing options that are available from PowerSHAPE. This combination means that simple repairs can be carried out quickly and easily, while more complex problems can be overcome by deleting and replacing the existing surfaces within the model.

The first stage in using the Solid Doctor is to analyse the model using the Parasolid checking mechanisms, to determine the extent of any inconsistency issues in topology or geometry when the data is examined with the high levels of precision of Parasolid. Solid Doctor divides these issues into separate categories and labels the model. For each category or class of inconsistency, Solid Doctor recommends the most appropriate course of action, including a possible automatic fix.

The user then applies the automated repair sequence. This uses a combination of the healing technology in Parasolid, plus some extra Delcam tools, for example, to correct surfaces that have had their orientation reversed. These automated tools are typically different for each class of inconsistency, as experience has shown that what is effective in one case does not necessarily work for another. Each corrected issue has its label changed from red to green as it is repaired. The repairs can be inspected individually to ensure that the results are as required or the whole model can be checked again to highlight any further inconsistencies.

The second repair stage involves using Delcam’s unique trim region editing tools to correct larger issues that require manual repair by a skilled user, such as mismatches between the edges of the various surfaces within the model. These include direct editing options for the trim boundaries, which allow very quick and flexible adjustment of the surface edges to overcome errors in the model.

For the more serious problems that remain, it will usually be necessary to generate replacement surfaces in the affected area. This can be done easily using PowerSHAPE’s Smart Surfacing technology. The user simply deletes the existing surfaces and sketches around the area to be repaired. PowerSHAPE will then analyse the boundary and suggest the most appropriate type of surface to fill the space. Tangency can be maintained with the surrounding surfaces if required. If the user is not happy with the initial selection made by the software, he can run through alternative solutions until he is satisfied with the result.

Once the user is happy with the quality of the repaired surfaces, they are automatically incorporated back into the Parasolid model. This process continues until all the inconsistencies have been resolved and a valid Parasolid model created. By giving the user total control over how the part is repaired, even very poor quality or badly damaged data can be repaired quickly and efficiently to create a valid Parasolid model.

Despite the many improvements made in data translation in recent years, it still remains a multi-million dollar problem for manufacturers that need to pass CAD data up and down a supply chain. Delcam’s Solid Doctor will provide a quick and easy solution to this problem and so allow faster and more efficient new product development.