Mesh/pl

Wprowadzenie
W FreeCAD słowo "Siatka" jest zwykle używane w odniesieniu do obiektu siatki (klasa ), typu obiektu, który definiuje dane 3D, ale nie jest "kształtem" bryły.

Siatki to bardzo proste obiekty, zawierające jedynie wierzchołki (punkty), krawędzie i trójkątne ściany. Ogólnie rzecz biorąc, są one łatwe do tworzenia, modyfikowania, dzielenia i rozciągania, i mogą być przekazywane z jednej aplikacji do drugiej bez utraty szczegółów. Ponadto, ponieważ siatki zawierają bardzo proste dane, aplikacje 3D, takie jak oprogramowanie do animacji i gry wideo, mogą zarządzać bardzo dużymi ich ilościami (milionami trójkątów) bez zużywania dużych zasobów obliczeniowych.

However, in the field of engineering meshes present one big limitation: they are only made of surfaces, and have no "mass" information, so they don't behave like "solids". This means that solid-based operations, like boolean addition or subtraction, are difficult to perform on meshes. Also, since they are defined by individual points, they are hard to describe in a parametric fashion.

See Mesh MeshObject for more information about this type of object, and see Polygon mesh for generic information in computer systems.



Użycie
Meshes are normally created by internal functions of the Mesh Workbench, or by importing mesh format files, like STL and OBJ.

Essentially, every object derived from a Mesh Feature ( class) is expected to hold and manipulate a Mesh.

Since FreeCAD is primarily designed to be a solid modeller, it is better suited to deal with solid Shapes. It can import and display Meshes in the 3D view, and the Mesh Workbench offers some commands to directly manipulate them. But in many cases the Mesh first needs to be converted to a Shape (see Part ShapeFromMesh), or the geometry needs to be recreated using solid modelling techniques from the Part Workbench or the PartDesign Workbench.

Finite element meshes
In FreeCAD the word "Mesh" may also refer to a specific object that will be used in finite element analysis (FEA).

When an object with a solid Shape is used in the FEM Workbench it will be discretized into a triangular mesh. In this case, the resulting object is a FEM FemMeshObject ( class), and is not derived from a Mesh Feature ( class).

For more information see FEM Workbench and FEM Mesh.

Informacje dodatkowe

 * Geometria poligonalna (siatkowa)