# The NPart Object

## 1. Introduction

NPart objects extract part of a mesh from a Model object and the corresponding solution data from one or several Field objects. This is displayed as a 3D geometry in one or several Scene objects.

The creation of NPart objects is described in Section 2.

The NPart object's functionality is grouped in the following categories:

• Extraction. Many different extraction methods are provided: Extract whole elements, non-connected faces, faces specially marked (useful in CFD post-processing for the wall, far field, and symmetry plane), nodes, cuts through the volume, iso-surfaces, etc. These methods can be combined: For instance, the wall of an aircraft can be extracted, and at the same time, a cut through the volume can be made. See Section 3.

• Display settings. These settings control how the extracted mesh is displayed. The default colours for lines, faces, edges, etc. can be set, the lighting properties can be adjusted, and the mirror settings (useful for half- and quarter-models) can be defined. Many of the settings are useful for pre-processing (for examination of mesh quality and correctness). This includes display of node and element numbers, and of node-, element-, and material-coordinate systems. See Section 4.

• Application of solution fields. These settings control how solution fields are displayed on the extracted mesh. Various methods are provided: Colouring, iso-lines, sampling points, surface streamlines, deforming of the mesh, vectors. See Section 5.