Strong Geometry Support Is Meshing's Foundation
Pointwise's proprietary geometry kernel supports hybrid geometry so that you can work simultaneously with analytic (NURBS) or discrete (faceted) surfaces. Geometry models are imported from CAD native, neutral, and standard file formats.
Solid Modeling and Solid Meshing
Myriad issues can result in geometry models that are less than watertight, leaving gaps between surfaces that are large enough to cause problems for meshing. Pointwise's Solid Meshing suite of features is designed to avoid these types of problems from the start. By forming the geometry model into a watertight solid, gaps are closed implicitly so that meshing can proceed without a hitch. Pointwise has implemented a broad range of solid modeling operations, some that are performed automatically during geometry file import and others than can be fine-tuned for just a portion of the model.
In the Solid Meshing approach, quilts are assembled within the watertight geometry model (left). Each quilt is then meshed with a single surface mesh (right) regardless of the underlying topology of the geometry.
An important concept in Solid Meshing is the quilt, a subregion of the geometry that reflects the design intent (for example, the hood of a car or the upper surface of a wing) that will be meshed as a single unit regardless of the number of geometry surfaces supporting it. At its simplest, every trimmed surface in the geometry model is a quilt. But assemble adjacent trimmed surfaces into a larger quilt and your mesh topology will be simplified.
Both solid model and quilt assembly can be performed automatically during geometry model import.
When technical reasons or personal preference prevent you from applying Solid Meshing, Fault-Tolerant Meshing is your alternative. A technique called merging automatically identifies adjacent surface meshes, joins them across geometry model gaps, and uses the mesh solver to remove geometry artifacts such as topology and sliver surfaces from the mesh.
In the Fault-Tolerant Meshing approach, the Merge command is used to make meshes match over gaps in the underlying geometry model.
Working with Faceted Geometry
When working with faceted geometry, it is often necessary to recover the topology of the geometry so that feature lines (also known as hard edges) are reproduced accurately in the mesh. Pointwise provides feature extraction, the ability to identify feature lines in the faceted surfaces based only a turning angle. Feature extraction can be performed automatically during geometry import or interactively on any portion of the geometry model.
Shell entities (the surfaces in a faceted geometry model) can be intersected just like any other geometry entity in the model. They can also be split by cutting them with planes, both constant coordinate planes and any arbitrarily oriented plane you create.
Pointwise does not require a geometry model for meshing – the mesh can be created directly in 3D without having to create geometry first. This feature lets you use geometry from CAD only where necessary. Furthermore, Pointwise's built-in geometry modeler may be used to supplement what is imported from a CAD system or create new models from scratch.
When meshing complex geometry models, Pointwise can create meshes that are independent of the model's surface topology. A mesh may span an entire surface, only a portion of a surface, or multiple surfaces.