What is Reverse Engineering?

Understanding Reverse Engineering

Reverse engineering in CAD involves reconstructing a parametric CAD model from existing data. The goal is to convert non-parametric data, such as faceted models, into parametric data for easier manipulation, analysis, and manufacturing.

• Faceted Models (STL) and Parametric CAD Data (STP): To grasp the reverse engineering process, it's important to distinguish between faceted models and parametric CAD data. Faceted models, represented by the STL format, consist of triangulated facets derived from a point cloud. On the other hand, parametric CAD data, typically in the STP format, is defined by planes, UV surfaces, and dimensions.

The Reverse Engineering Process in Practice

Reverse engineering involves gathering data from existing models. This step can be performed using 3D scanners, which capture precise information about an object's geometry. This data serves as a basis for reconstructing the parametric model.

The time and complexity of the reverse engineering process may vary depending on the model's geometry and specific objectives. Simple shapes can be quickly reconstructed, while more complex shapes require more time and effort.

 

 

Tools and Methods for Reverse Engineering

Several tools and methods are available to facilitate the reverse engineering process in CAD. Among them, convergent modeling enables working directly with faceted models, like STL, in CAD software such as Siemens NX. This approach offers features for modifying, repairing, and enhancing the quality of the model's facets.

Primitive detection is another useful method, especially for prismatic shapes. It allows for the rapid generation of parametric surfaces, such as planes or cylinders, using recognized dimensions. This simplifies the design of a functional and precise model.

For more complex shapes, algorithmic modeling can be utilized. This approach automates the process of creating or modifying geometry by automatically extracting section curves from the model.

 

Combining STL and Parametric

In some cases, combining STL data with parametric features can be advantageous in a CAD workflow. This allows leveraging the precise geometric details of the STL while adding the flexibility and modifiability of parametric data in the STP format.

In summary

Reverse engineering in CAD offers numerous possibilities for converting faceted models into parametric ones. With the available tools and methods, it is possible to accurately reconstruct existing objects, make modifications, and use them in manufacturing processes. This approach opens up new perspectives in 3D design and modification, providing increased flexibility to engineers and designers !