GiD_Mesh

To create, delete, modify, list or know information about mesh nodes or elements of the preprocess:

create: to create a new node or element

GiD_Mesh create node <num>|append <x y z>

<num>|append: <num> is the identifier (integer > 0) for the node. You can use the word 'append' to set a new number automatically. The number of the created entity is returned as the result.
<x y z> are the node coordinates. If the z coordinate is missing, it is set to z=0.0.

GiD_Mesh create element <num>|append <elemtype> <nnode> <N1 ... Nnnode> <radius> <nx> <ny> <nz> ?<matname>?

<num>|append: <num> is the identifier (integer > 0) for the node. You can use the word 'append' to set a new number automatically. The number of the created entity is returned as the result.
<elemtype>: must be one of "Point | Line | Triangle | Quadrilateral | Tetrahedra | Hexahedra | Prism | Pyramid | Sphere | Circle"
<nnode> is the number of nodes an element has
<N1 ... Nnnode> is a Tcl list with the element connectivities
<radius> is the element radius, only for sphere and circle elements
<nx> <ny> <nz> is the normal of the plane that contain the circle, must be specified for circle elements only
<matname> is the optional element material name

delete: to delete one or more nodes or elements

GiD_Mesh delete ?-also_lower_entities? node|element <num_1 ... num_n>

-also_lower_entities to delete the elements and also its dependent nodes when possible (nod depend on other elements or have applied conditions)

<num> is the identifier (integer > 0) for the node or element to be deleted. It is possible to use a list of multiple ids.

edit: to modify a node or element
GiD_Mesh edit node <num> <x y z>

GiD_Mesh edit element <num> <elemtype> <nnode> <N1 ... Nnnode> <radius> <nx> <ny> <nz> ?<matname>?
Same syntax as create

or

GiD_Mesh edit node|element <num> material|label_on|selected <value>

<num> the entity id

<material> to set the material number (value>=0)

<label_on> to set the label flat (value 0 or 1)

<selected> to set the selection flag (value 0 or 1)

get: to get the information of a node or element

GiD_Mesh get node <num> ?coordinates|material|label_on|selected|higherentity?
It return the list: <node_layer> <x> <y> <z>
with the extra word

coordinates only the <x> <y> <z> coordinates are returned
material: the material integer id is returned
label_on: 0 or 1 is returned (label flag)
selected: 0 or 1 is returned (selection flag)
higherentity: integer >=0 with the counter of parent elements using this node

<num> is the identifier (integer > 0) for the element to be asked
face optional, instead of the element nodes it returns the nodes of the face, first the linear corner nodes and then the quadratic nodes
face_linear optional, instead of the element nodes it returns only the linear corner nodes, also is the element is quadratic
num_faces returns the amount of faces of the element (for surface elements its edges act as faces)
<face_id> is the local face index from 1 to the number of faces of the element. If <face_id> is missing then a list with all faces is returned
edge_linear optional, instead of the element nodes it returns only the linear edge nodes, also is the element is quadratic
num_edges returns the amount of edges of the element
<edge_id> is the local edge index from 1 to the number of edges of the element. If <edge_id> is missing then a list with all edges is returned
normal return a 3D vector with the normal direction for surface elements (and for line elements in 2D the normal to the tangent)
tangent return a 3D vector with the tangent direction for line elements
center return a 3D vector with the element center
connectivities return a list of integers with the element's nodes
geometry_source return a list where the first item is the category: POINT_LT|LINE_LT|SURFACE_LT|VOLUME_LT and then the integer ids of the geometric entity source of the mesh element (usually one entity, but could be more than one meshing with Rjump)
material: the material integer id is returned
label_on: 0 or 1 is returned (label flag)
selected: 0 or 1 is returned (selection flag)

get element return the list: <element_layer> <elemtype> <nnode> <N1> ... <Nnnode>
get element face|face_linear: <N1_face> ... <Nnnode_face>
get element edge_linear: <N1_edge> <N2_edge>

If from_face is specified then the command has this syntax
GiD_Mesh get element from_face <face_nodes> ?-ordered?
it find and return the list of element ids that have a face with these nodes

<face_nodes> is the list of integer ids of the face nodes {<face_node_1> ... <face_node_n>} (only corner lineal nodes must be specified in the list)
if -ordered is specified then only faces with the same orientation of the nodes and start node of the GiD faces definition will be taken into account (else the order of the face nodes doesn't matter)

If from_edge is specified then the command has this syntax
GiD_Mesh get element from_edge <edge_nodes>
it find and return the list of element ids that have an edge with these nodes

<edge_nodes> is the list of integer ids of the edge nodes {<edge_node_1> <edge_node_2>} (only corner lineal nodes must be specified in the list)

If from_node is specified then the command has this syntax
GiD_Mesh get element from_node <node_id>
it find and return the list of element ids that have this node

<node_id> is the integer id of the node

Note: get element from_face, from_edge of from_node could be an expensive operation because the whole mesh is traversed to find them.

GiD_Mesh get nodesdistance <num1> <num2>
returns the distance between two mesh nodes, specified by its numbers

list: to get a list of entity identifiers of a range, filtered with some conditionals

GiD_Mesh list ?<filter_flags>? node|element|face ?<num>|<num_min:num_max>?

<filter_flags> could be: ?-count? ?-higherentity <num_higher>? ?-material <id_material>? ?-layer <layer_name>? ?-plane {a b c d r}? ?-element_type <types_allowed>? ?-orphan? ?-avoid_frozen_layers?

-count to return the amount of entities instead of the objarray with its ids
-higherentity <num_higher> to filter the selection and list only the entities with the amount of parents equal to <num_higher> (integer >=0)
-material <id_material>to filter the selection and list only the entities with material id equal to <id_material> (integer >=0)
-layer <layer_name>to filter the selection and list only the entities with layer equal to <layer_name>
-plane <a b c d r> to list only the entities with center that match the plane equation a*x+b*y+c*z+d<=r (r>=0.0)
-element_type <types_allowed> to list only the elements of a type contained in <types_allowed>, that must be a list of allowed types ("Point | Line | Triangle | Quadrilateral | Tetrahedra | Hexahedra | Prism | Pyramid | Sphere | Circle")

-orphan to list only the orphan elements, that do not belong to the mesh of any geometrical entity,

-avoid_frozen_layers to ignore the entities on layers frozen

if <num> or <num_min:num_max> are not provided it is considered as 1:end, and then all ids are returned

In case of face it is returned a value with two lists: element_ids and face_index
Each face is identified by the element_id and the local face_index (form 1 to the number of faces of the element)

the valid flags are
GiD_Mesh list ?-unique? ?-normals_dotprod_threshold <threshold_value> -higherentity|higherentity_not <higherentity> -element_type <list_of_types> face
-unique is to avoid repeat faces shared between multiple elements, only one is arbitrary retained
-normals_dotprod_threshold <threshold_value> is to get only the faces (edges really) that belong to the surface elements with dot product of its normals below the threshold_value (from 1.0 to -1.0). e.g. -0.9 for problematic faces of folded elements. In this case is implicit -higherentity 2 and -element_type {triangle quadrilateral}
-higherentity <higherentity> is to get only faces that belong exactly to <higherentity> elements (an integer number > 0)
-higherentity_not <higherentity> is to get only faces that not belong to <higherentity> elements
-element_type <list_of_types> is a list of types of elements (faces of other types are ignored). By now only triangle, quadrilateral

Examples:

GiD_Mesh create node append {1.5 3.4e2 6.0}
GiD_Mesh create element 58 triangle 3 {7 15 2} steel
GiD_Mesh delete element {58 60}
set triangles_and_quads [GiD_Mesh list -element_type {triangle quadrilateral} element]

exists: to check the existence of an entity

GiD_Mesh ?-pre|-post? exists node|element <id>

Note: another way to check if a node or element exists in old versions is to list it

e.g.

proc NodeExistsPre { node_id } {
  set exists 0
  if { [GiD_Mesh list node $node_id ] == $node_id } {
      set exists 1
  } 
  return $exists
}