The upcoming release of Polygonica from Sheffield-based Machine Works Ltd (www.machineworks.com) — a developer of CNC simulation and verification software — will include automatic feature recognition on poly-gonal solids.

The company says there are many CAD models in use that have lost their original surface data, and this loss of surface information often occurs when the CAD output is tessellated into a mesh.

Many processes subsequent to mesh conversion require the surface data that has been lost, but Polygonica introduces functionality that can regenerate the original surface information from just the triangulated data.

The feature-detection algorithm developed by Machine Works takes in the mesh information and automatically returns the surface parameterisation of the feature, as well as surface area, bounding box and error values.

The geometric features detected include planes, spheres, cones, cylinders and tori.

Moreover, boundaries around features can also be determined — and queried — allowing the application to tell which features are adjacent to other features. In one test using a solid with 5,776 triangles, Polygonica found 58 features in 0.63sec; in the case of another solid with 6,156 triangles, 41 features were found in just 1.94sec.

In a somewhat complex solid (automotive disc brake assembly) with 271,582 triangles, Polygonica found 6,368 features in 80.63sec.

David Knight, Polygonica sales manager, said: “The results speak for themselves. For polygonal meshes originally derived from CAD models, Polygonica feature detection can quickly and accurately determine a set of geometric features. This could provide a crucial first step in many tasks such as reverse engineering, re-meshing and automation.”