A Preliminary Study on Netgen Volume Meshing and Display of CAD Based on OSG+OCC

When I was integrating netgen before, the division option was surface mesh division, and there was no volume mesh division option. Recently, the company has not been very busy. I read Netgen's C++ API, so I added body mesh to my system.For mesh division and surface mesh division options, see the mesh type tab under Netgen parameter settings in the screenshot.

Nengen's core API for volume meshing is: Ng_GenerateVolumeMesh interface, followed by the interface for reading mesh data: Ng_GetNE to get the number of units, Ng_GetVolumeElement to get the specific unit coordinate label, and Ng_GetPoint to get the specific coordinates according to the label, which can be directly exchanged later.Just render it, the core code is extracted as follows:

ng_res = Ng_GenerateVolumeMesh(occ_mesh, &mp);//Volume meshing

int net = nglib::Ng_GetNE(occ_mesh);//Get the number of volume mesh elements

nglib::Ng_GetVolumeElement(occ_mesh, i, p);//Get the three coordinate subscript values ​​of the i-th unit

nglib::Ng_GetPoint(occ_mesh, p[0], pt);//Get the coordinate position of the first subscript

where p is: int p[3] = { 0.0 }; pt is: double pt[3] = { 0.0 };

The effect of rendering with OSG is as follows:

Figure 1. Stp model display

Where: the blue solids show the face mesh effect, and the black lines show the volume mesh effect.