MESH represents
- a discretization of a geometrical CAD model into a set of entities with
- a simple topology. In MESH there are two options of creation of meshes,
- you can: MESH represents
- a discretization of a geometrical CAD model into a set of entities with
- a simple topology. In MESH there are two options of creation of meshes,
- you can:
- -
generate meshes on the basis of geometrical shapes - produced in the GEOM module,
create your own meshes using the MESH functions - destined for modification of generated meshes.
- -
The topology of a mesh is described by the relationships between its - entities including:
- -- -
Node - 0D element of a mesh presented by a point with coordinates (x, y, z).
Edge - 1D element of a mesh defined by two nodes.
Face - 2D element of a mesh defined by three or four edges (closed contour).
Volume - 3D element of a mesh defined by several faces.
- -
These entities are considered as topological - entities and they don't imply any geometric representation. Only Nodes reference geometric - representations of points with definite coordinates. The - node entity will contain additional - information about its position in the space and its relations with the - meshed CAD model. Its position could be described in the following way:
- -- -
2D - position. It is a free position defined by only two coordinates - x,y.
3D - position. It is a free position defined by three coordinates x,y - and z.
Surface - position. It characterizes the position of a node on a geometric - surface and is defined by the u,v position in the parametric space of - the corresponding surface.
Line - position. It characterizes the position of a node on a geometric - curve and is defined by the u parameter and the corresponding curve.
Vertex - position. It characterizes the position of a node on a geometric - point of the meshed CAD model and is defined by the x,y,z coordinates - of the corresponding vertex.
- -
- -
Each mesh entity bounds 0 or more mesh entities - of higher dimension. In the same way each mesh entity is bounded by 0 - or more mesh entities of lower dimension:
- -- -
A node bounds edges, - faces and volumes
An edge bounds faces, - and volumes
A face bounds volumes
A volume is bounded - by faces, edges and nodes
A face is bounded by - edges, and nodes
An edge is bounded by - nodes
- -
You can notice that there are two types of - connections: inverse and direct connections.
- -- -
- -
This relationship has a particularity that - the order of bounded entities has not a direct meaning. Also the number - of bounded entities is not fixed.
- -- -
The edges surrounding a node.
- The 3rd edge has no more sense that the 5th one.
- -
Direct connections
- -- -
This relationship has a particularity that - the order of bounding entities is meaningful. The number of bounding entities - is fixed and depends on the type of the entity (hexahedron, tetrahedron, ).
- -- -
An edge is composed of two
- nodes. A face is composed of 3 or 4 edges depending if we are dealing
- with triangles or quadrangles.
- -
The connections are not only restricted to - entities of one dimension higher or lower. For example some algorithms - may be interested to retrieve all the faces surrounding a node.
- -- -
- -
- - - - + + + + + +
MESH represents
+ a discretization of a geometrical CAD model into a set of entities with
+ a simple topology. In MESH there are two options of creation of meshes,
+ you can:
+ +
generate meshes on the basis of geometrical shapes + produced in the GEOM module,
create your own meshes using the MESH functions + destined for modification of generated meshes.
+ +
The topology of a mesh is described by the relationships between its + entities including:
+ ++ +
Node + 0D element of a mesh presented by a point with coordinates (x, y, z).
Edge + 1D element of a mesh defined by two nodes.
Face + 2D element of a mesh defined by three or four edges (closed contour).
Volume + 3D element of a mesh defined by several faces.
+ +
These entities are considered as topological + entities and they don't imply any geometric representation. Only Nodes reference geometric + representations of points with definite coordinates. The + node entity will contain additional + information about its position in the space and its relations with the + meshed CAD model. Its position could be described in the following way:
+ ++ +
2D + position. It is a free position defined by only two coordinates + x,y.
3D + position. It is a free position defined by three coordinates x,y + and z.
Surface + position. It characterizes the position of a node on a geometric + surface and is defined by the u,v position in the parametric space of + the corresponding surface.
Line + position. It characterizes the position of a node on a geometric + curve and is defined by the u parameter and the corresponding curve.
Vertex + position. It characterizes the position of a node on a geometric + point of the meshed CAD model and is defined by the x,y,z coordinates + of the corresponding vertex.
+ +
+ +
Each mesh entity bounds 0 or more mesh entities + of higher dimension. In the same way each mesh entity is bounded by 0 + or more mesh entities of lower dimension:
+ ++ +
A node bounds edges, + faces and volumes
An edge bounds faces, + and volumes
A face bounds volumes
A volume is bounded + by faces, edges and nodes
A face is bounded by + edges, and nodes
An edge is bounded by + nodes
+ +
You can notice that there are two types of + connections: inverse and direct connections.
+ ++ +
+ +
This relationship has a particularity that + the order of bounded entities has not a direct meaning. Also the number + of bounded entities is not fixed.
+ ++ +
The edges surrounding a node.
+ The 3rd edge has no more sense that the 5th one.
+ +
Direct connections
+ ++ +
This relationship has a particularity that + the order of bounding entities is meaningful. The number of bounding entities + is fixed and depends on the type of the entity (hexahedron, tetrahedron, ).
+ ++ +
An edge is composed of two
+ nodes. A face is composed of 3 or 4 edges depending if we are dealing
+ with triangles or quadrangles.
+ +
The connections are not only restricted to + entities of one dimension higher or lower. For example some algorithms + may be interested to retrieve all the faces surrounding a node.
+ ++ +
+ +
+ + + +