Delcam has introduced a new version of its CopyCAD reverse engineering software that offers faster and more accurate alignment of multiple scans, together with new curve creation and editing tools for easier surfacing, and improvements to its abilities to develop horizon lines and to fill any gaps in the scanned data.

The improved alignment options will make it easier to match accurately data collected from a series of scans of different parts of the model.  Once the key features within the data have been aligned approximately, the software will simultaneously combine all the data into a single model.  This is much faster than the previous method in which data from each scan was added to the model progressively.  It also prevents the tolerance stack-up that could occur when combining a large number of scans.  The new approach can be used either directly on a series of sets of scanned points or on the triangle models created from individual scans.

The new curve creation options make sketching of wireframe geometry much easier, both in cases where the curves will be used as construction geometry and when they will be used to divide the model into regions for rapid surface creation.  The additional editing options include greater control over the tangency and parameterisation of the curves.  The software can also snap the curve back to the surface of the scan data automatically if the editing option would have lifted it away from the model.

These new options have also contributed to the improved generation of the horizon line of the model.  This is essential for users that want to produce tooling designs from scan information, without first surfacing the data.  A smooth horizon line can now be generated within CopyCAD, even from models made up from coarse triangle files.

CopyCAD has been able for several releases to fill holes in the model resulting from missing or sparse data.  This functionality has now been improved to give closer tangency matching to the scanned data, with no gaps or overlaps between the surface generated and the remainder of the model.

The latest CopyCAD release comes at a time when there is a resurgence of interest in reverse engineering, after a period when it was widely believed that the technique would be replaced completely by computer-based design methods.  This renewed interest was highlighted last year when CopyCAD was the winner of the Desktop Engineering Readers' Choice Award for October.

Even those companies using CAD successfully for the majority of their modelling requirements still have some designers working with very complex shapes that prefer to produce models by hand.  The time and effort needed to retrain those people in new computerised design techniques may make it impractical to change their working methods, especially if they are reluctant to abandon their original skills.  Often, it is easier to leave such craftsmen to work with their traditional methods and capture the results with reverse engineering to generate CAD models.

Of course, a combination of both techniques can be used to obtain the final CAD model that is needed.  For companies that wish to work in this way, Delcam's Total Modelling approach to design allows users to build up CAD models with data from different sources.  For example, Total Modelling makes it easy to design the main outline of a product with CAD, but use hand models for complex details or decoration.  The hand-modelled sections can then be digitised and combined with the main CAD model in the computer.

A similar approach can be taken when developing "new" parts that are, in fact, variations on existing components.  It is often quicker to digitise the existing part and limit the CAD work to the desired modifications, instead of completely recreating the whole part with CAD.