What is reverse engineering? When it is necessary to reproduce or redesign already existing objects for which the CAD file is not available, laser scanning is used to acquire the geometries and the 3D mathematical structure of the piece in order to create an object with similar or better characteristics.
The first step consists in the 3D scanning of the object to be reproduced through the use of a touch probe or video projector investing it with a light beam, defined as structured light scanning.
Reverse engineering, the term structured light
The term structured light refers to a three-dimensional sensing technique that often uses a laser beam, special lenses and cameras to project a pattern, such as lines, onto an object.
Depending on how the object is projected allows the instrument’s calculation systems to derive the depth of the scanned objects, also obtaining various surface information.
Then the corresponding software performs a triangulation of the points. It reconstructs the position and shape of the object by generating a triangular mesh. Highly refined models of this type allow detailed modifications to be made.
The mesh model: what is it about?
A mesh model consists of vertices, edges, faces using a polygonal representation, defining a 3D shape. A mesh has no mass properties.
The second step is performed by an operator, who through the use of software, transforms the mesh into a quadrangular polygon, optimizing the model.
The mesh is checked and corrected possible errors due to scanning, then any changes are made. Finally, the mathematics of the model obtained are extrapolated, which will be used to make the new part, but also to perform subsequent FEM analysis, then it will be possible to use the mathematics to make the component in Additive Manufacturing.