Modelling of NURBS-generated surface and solid data.
The everyday question is: "Can the scan data be saved in a CAD model? Based on the scan data, a parametric CAD model or a freeform CAD model can be generated. What is important to convert scan data into useful CAD geometry?
If a fully editable (parametric) CAD model is not required, the construction of surface and solid models using free-form surfaces is a cost-effective option. This procedure is best suited for organic surfaces from nature or if the surface structure is to be retained. The CAD models created in this way are often referred to as "stupid" CAD data or as NURBS-generated CAD data.
Curve network Side view
Curved network Front view
NURBS fitting deviations
In the first step, a polygonal model is created and optimized from the 3D point cloud. For this all points are connected with their neighboring points. The result are thousands of polygons describing the surface of the scanned object.
Next, a special CAD software "lays" a curve network over the scan object. Some scan objects require several hours of optimization of the curve network before the final free-form surfaces can be calculated.
The result is a NURBS-generated surface or solid model in IGES or STEP format. The generated surfaces lie with a high accuracy on the scan data and thus reflect the real object precisely. The CAD models can be scaled, trimmed and merged, but it is not possible to thicken them without restrictions or to edit parts of them. This lies in a fundamentally different mathematical approach to the parametric CAD model.
The answer to the question "Can the 3D scan data be saved in a CAD model?
No scanning technology offers the possibility to convert a point cloud into a CAD model (at least not yet). Some special CAD programs speed up the process of developing a CAD model, but they are not intuitive enough to create a usable model.
Every step in building a freeform surface depends on the design, function, surface and sharp edges. This information is needed by an experienced designer to create a complete model that includes the exact shape, dividing lines, and accuracy required.
Through your clearly defined specifications, we will create a CAD model for you that will take you a big step forward.
sigma3D calls it: Geometry you can trust.