The following commands are available on the Geometry/Vertex subpad.
The Create Vertex command button allows you to perform the following operations.
The Create Real Vertex operation (vertex create coordinates command) creates a real vertex at a specified location.
To open the Create Real Vertex form (see below), click the Create Real Vertex command button on the Geometry/Vertex subpad.
The Create Real Vertex form includes the following specifications.
Coordinate Sys.  specifies the coordinate system with respect to which the vertex position is specified. (See Section 2.1.3.) 
Type  
Cartesian Cylindrical Spherical 
specifies the type of coordinate parameters to be used in creating the vertex. 
Global  Local  specifies the location of the vertex with respect to either the Global or Local system. 
Label  specifies a label for the new vertex. (See Section 2.1.1). 
The Create Vertex on Edge operation (vertex create onedge or vertex create vonedge command) creates a real or virtual vertex on an existing edge.
When you create a vertex on an edge, GAMBIT associates a position parameter, u, with the vertex creation point. The position parameter represents the fraction of total edge length measured from the start endpoint of the edge. For example, if you locate the creation point at the exact center of the edge, the value of u is 0.5.
The default value of u depends on the method used to specify the edge upon which the vertex is created. There are two ways to specify the edge:
If you specify the edge by means of the mouse, GAMBIT assigns a value of u corresponding to the exact point at which the edge was selected. For example, if you select the edge by picking a point 27.3% of the distance along the edge as measured from the start endpoint, GAMBIT assigns a value of u equal to 0.273. To reposition the vertex using the mouse, drag the vertex along the edge.
NOTE: When you pick the edge on which the vertex is to be created and release the mouse button, GAMBIT fixes the position of the vertex creation point. If you release the mouse button before the creation point is at the desired position, you can reposition the creation point in one of three ways:

To open the Create Vertex on Edge form (see below), click the Create Vertex on Edge command button on the Geometry/ Vertex subpad.
The Create Vertex on Edge form includes the following specifications.
Edge  specifies the edge upon which the vertex is created. 
Type:  
Real  creates a real vertex. 
Virtual  creates a virtual vertex. 
U Value  specifies the value of the position parameter, u. 
Coordinate Sys.  specifies the coordinate system with respect to which the vertex position is specified. (See Section 2.1.3.) 
Type  
Cartesian Cylindrical Spherical 
specifies the type of coordinate parameters to be used in creating the vertex. 
Global  Local  specifies the location of the vertex with respect to either the Global or Local system. 
Label  specifies a label for the new vertex. (See Section 2.1.1.) 
The Create Vertex on Face operation (vertex create onface or vertex create vonface command) creates a real or virtual vertex on an existing face.
When you create a vertex on a face, GAMBIT associates two position parameters, u and v, with the vertex creation point. The position parameters represent coordinates for a twodimensional mapping of the creation point. The default values of u and v depend on the method used to specify the face upon which the vertex is created. There are two ways to specify the face:
If you specify the face by means of the mouse, GAMBIT assigns values of u and v corresponding to the point at which the face was selected. To reposition the vertex using the mouse, drag the vertex in any direction along the face.
NOTE: When you pick the face on which the vertex is to be created and release the mouse button, GAMBIT fixes the position of the vertex creation point. If you release the mouse button before the creation point is at the desired position, you can reposition the creation point in one of three ways:

To open the Create Vertex on Face form (see below), click the Create Vertex on Face command button on the Geometry/Vertex subpad.
The Create Vertex on Face form contains the following options.
Face  specifies the face upon which the vertex is created. 
Type:  
Real  specifies the creation of a real vertex. 
Virtual  specifies the creation of a virtual vertex. 
U Value  specifies the value of the position parameter, u. 
V Value  specifies the value of the position parameter, v. 
Coordinate Sys.  specifies the coordinate system with respect to which the vertex position is specified. (See Section 2.1.3.) 
Type  
Cartesian Cylindrical Spherical 
specifies the type of coordinate parameters to be used in creating the vertex. 
Global  Local  specifies the location of the vertex with respect to either the Global or Local system. 
Label  specifies a label for the new vertex. (See Section 2.1.1.) 
The Create Virtual Vertex on Volume operation (vertex create vonvolume command) creates a virtual vertex associated with an existing volume.
Regardless of whether you specify the volume by means of the Volume list box or by means of the mouse, GAMBIT locates the vertex creation point in the center of the volume by default. To reposition the creation point, you must input its location coordinates.
GAMBIT does not require the new vertex to be located within the volume with which it is associated. Therefore, if you specify vertex coordinates that lie outside the volume, GAMBIT does not "snap" the vertex to the volume.
NOTE: You cannot use the mouse to create or relocate a virtual vertex associated with a volume. 
To open the Create Virtual Vertex on Volume form (see below), click the Create Virtual Vertex on Volume command button on the Geometry/Vertex subpad.
The Create Virtual Vertex on Volume form contains the following options.
Volume  specifies the volume with which the created vertex is associated. 
Coordinate Sys.  specifies the coordinate system with respect to which the vertex position is specified. (See Section 2.1.3.) 
Type  
Cartesian Cylindrical Spherical 
specifies the type of coordinate parameters to be used in creating the vertex. 
Global  Local  specifies the location of the vertex with respect to either the Global or Local system. 
Label  specifies a label for the new vertex. (See Section 2.1.1.) 
The Create Vertices at Edge Intersections operation (vertex create edgeints command) creates real or virtual vertices at the points of intersection (or closest approach) between any two specified edges. Vertices created by means of this operation are not connected to either of the edges used to define the points of intersection.
The Create Vertices at Edge Intersections command requires the following input parameters:
You can specify any combination of real and/or nonreal edges to define the points of intersection (or closest approach) at which vertices are to be created. If you specify two edges that intersect or approach each other at more than one location, GAMBIT creates a separate vertex at each point of intersection or closest approach. The types of edges (real or nonreal) used to define the points of intersection do not affect the types of vertices that result from the vertex creation operation (see below).
If you specify two edges that intersect or approach each other at or near the endpoint(s) of one of the edges, GAMBIT determines whether or not to create new vertices according to the following criteria (see Figure 226):
Figure 226: Create Vertices at Edge Intersections—Endpoint criteria
The Create Vertices at Edge Intersections command can be used to create vertices for sets of edges that do not exactly intersect as long as the edges nearly intersect at their points of closest approach. Specifically, when you select the Tolerance option, GAMBIT creates vertices at the points of closest approach the distances between which are less than a given tolerance value.
GAMBIT provides two Tolerance options:
When you create vertices using edges that do not exactly intersect, GAMBIT locates the vertices on the edge specified in the Edge 1 picklist box. For example, if you specify two nonintersecting edges, v_edge.5 and edge.17, as Edge 1 and Edge 2, respectively, and specify an appropriate Tolerance value, GAMBIT locates any created vertices on v_edge.5.
The Create Vertices at Edge Intersections command allows you to create real or virtual vertices regardless of whether the edges that define the points of intersection are, themselves, real or nonreal. For example, it is possible to create a real vertex at the point of intersection between two virtual edges or between a real edge and a virtual edge.
To open the Create Vertices at Edge Intersections form (see below), click the Create Vertices at Edge Intersections command button on the Geometry/Vertex subpad.
The Create Vertices at Edge Intersections form contains the following specifications.
Edge 1  specifies the first of two edges the intersection point(s) of which locate(s) the position of the created vertex (or vertices). 
Edge 2  specifies the second of two edges the intersection point(s) of which locate(s) the position of the created vertex (or vertices). 
Tolerance  specifies that vertices are created only where the distances of closest approach between the specified edges are less than a tolerance value. GAMBIT provides two Tolerance options:

Virtual  specifies that all created vertices are virtual vertices. 
Label  specifies a label for the first created vertex. (See Section 2.1.1.) 
The Create Real Vertex at Centroid operation (vertex create centroid command) creates a real vertex at the centroid of a volume, face, or edge. To execute the operation, you must specify the entity (volume, face, or edge) at the centroid of which the vertex is to be created.
To open the Create Real Vertex at Centroid form (see below), click the Create Real Vertex at Centroid command button on the Geometry/Vertex subpad.
The Create Real Vertex at Centroid form contains the following specifications.
Volume Face Edge 
specifies the type of entity to be used in defining the vertex creation point. 
Volume Face Edge 
specifies the entity at the centroid of which the vertex is to be created. 
Label  specifies a label for the created vertex. (See Section 2.1.1.) 
The Project Vertices on Edge operation (vertex create project command) creates real vertices that represent the projection of existing vertices onto an existing edge. The operation requires the following input specifications:
To open the Project Vertices on Edge form (see below), click the Project Vertices on Edge command button on the Geometry/Vertex subpad.
The Project Vertices on Edge form contains the following specifications.
Vertices  specifies the vertices to be projected onto the edge. 
Edge  specifies the edge onto which the vertices are to be projected. 
Split edge  splits the target edge (using each of the created vertices). 
Label  specifies a label for the first created vertex. (See Section 2.1.1.) 
The Slide Virtual Vertex operation (vertex move virtual command) moves a virtual vertex that is hosted by an edge, face, or volume. You cannot move an edge or facehosted vertex to any position that does not lie on its host entity; however, you can move a volumehosted vertex to any location inside or outside the volume.
NOTE: When you move a virtual vertex by means of the Slide Virtual Vertex operation, GAMBIT changes the shapes and positions of any highertopology virtual entities to which the vertex is connected. For example, if you move a virtual vertex that constitutes one apex of a virtual pyramid, GAMBIT changes the shape of the pyramid to reflect the new position of the vertex. 
The methods available for moving (sliding) a virtual vertex depend on its host entity type. For a volumehosted vertex, you must specify the coordinates of the new vertex location. For an edge or facehosted vertex, GAMBIT provides three options for moving the vertex:
You can use the Slide Virtual Vertex command to move a connecting vertex that results from a virtual edgesplit operation (see "Split Edge," in Section 2.3.5, below). Doing so allows you to change the relative lengths of the two virtual edges created by the operation.
If the host edge for the vertex to be moved is part of a set of meshlinked edges, GAMBIT allows you to specify whether or not to move the corresponding vertices for all linked edges in the set. The specification is made by means of the Move with links option on the Slide Virtual Vertex form, which operates as follows.
NOTE (1): If any edge in the set of meshlinked edges is itself hosted by a face or volume, GAMBIT automatically excludes its connecting vertex from the Slide Virtual Vertex operation regardless of whether or not you specify the Move with links option. 
NOTE (2): If you slide a connecting vertex the host edge of which is periodically linked to other edges, GAMBIT slides the corresponding vertices on the linked edges regardless of whether or not you select the Move with links option. 
NOTE (3): If you slide a virtual vertex created by means of the Create Vertex on Edge command on an edge that is part of a set of linked edges, GAMBIT slides only the vertex specified for the slide operation regardless of whether or not you select the Move with links option. 
To open the Slide Virtual Vertex form (see below), click the Slide Virtual Vertex command button on the Geometry/Vertex subpad.
The Slide Virtual Vertex form includes the following specifications.
Vertex  specifies the vertex to be moved. 
U Value  specifies the value of the position parameter, u (edges and faces). 
V Value  specifies the value of the position parameter, v (faces only). 
Coordinate Sys.  specifies the reference coordinate system for coordinate input values. (See Section 2.1.3.) 
Type  
Cartesian Cylindrical Spherical 
specifies the type of coordinate parameters to be used in creating the vertex. 
Global  Local  specifies the new location of the vertex with respect to either the Global or Local system. 
Label  specifies a label for the vertex. (See Section 2.1.1.) 
Move with links  moves all vertices on edges that are linked to the selected host edge. 
The Connect/Disconnect Vertices command button allows you to perform two operations.
The following sections describe the procedures and specifications required to execute the operations listed above.
NOTE: The Specify Color Mode command button on the Graphics/Windows Control toolpad allows you to display model colors based on entity connectivity rather than topology. For a description of the use of the Specify Color Mode command button, see the GAMBIT User's Guide, Section 3.4.2. 
The Connect Vertices operation (vertex connect command) connects sets of two or more vertices. When you connect a set of vertices, GAMBIT replaces the vertices in the set with a single vertex.
NOTE: If any of the vertices to be connected are meshlinked to other vertices in the model, GAMBIT preserves the mesh link(s) and assigns it/them to the single vertex that results from the connect operation. 
To connect vertices, you must specify the following parameters:
The vertices to be connected can be real or virtual, but they are subject to certain restrictions imposed by the connection type (see below).
There are four types of vertex connection operations:
The Real option allows you to connect coincident real vertices. When you connect real vertices and specify the Real option, GAMBIT deletes all but one of the specified vertices and connects the remaining real vertex to all higher topology associated with the deleted vertices.
NOTE: For the purpose of connecting vertices, GAMBIT defines coincidence with respect to a global tolerance value of 10^{6}. 
As an example of the Real connection operation, consider the configuration shown in Figure 227, in which two real, unconnected edges are located such that two of their endpoint vertices (vertex.2 and vertex.3) are coincident.
Figure 227: Connecting vertices, Real option
If you connect vertex.2 and vertex.3 by means of the Real connection operation, GAMBIT deletes vertex.3 and redefines edge.2 such that its endpoints are vertex.2 and vertex.4. As a result, edge.1 and edge.2 share a common endpoint—that is, vertex.2—and are, therefore, connected.
The Virtual (Forced) option allows you to connect real or virtual vertices, regardless of their proximity to each other. When you connect vertices and specify the Virtual (Forced) option, GAMBIT replaces all of the specified vertices with a single virtual vertex. If a specified vertex constitutes the endpoint of an edge, GAMBIT overlays the edge with a virtual edge and positions the virtual edge according to the location of the new virtual vertex. If the edge is connected to a face and/or volume, GAMBIT overlays the face and/or volume with a corresponding virtual entity.
The Virtual (Tolerance) option allows you to specify that only those vertices that are near to each other to within a specified tolerance are connected. There are two ways to express the tolerance value:
When you specify the Real and Virtual (Tolerance) option, GAMBIT performs the following two operations in sequence:
If you connect a set of vertices using a Virtual (Forced), Virtual (Tolerance), or Real and Virtual (Tolerance) operation, you can specify the location of the resulting vertex by means of the Preserve first vertex location option. When you select the Preserve first vertex location option, GAMBIT places the vertex resulting from the connect operation at the location of the first vertex listed in the Vertices list.
As an example of the effect of the Preserve first vertex location option, consider the set of edges shown in Figure 228(a).
Figure 228: Effect of Preserve first vertex location option
If you connect vertex.1 and vertex.3 by means of either the Virtual (Forced) or Virtual (Tolerance) operation, the location of the created vertex (v_vertex.5) and shapes of the created edges (v_edge.3 and v_edge.4) depend on which original vertex is listed first in the Vertices list.
To open the Connect Vertices form (see below), click the Connect command button on the Geometry/Vertex subpad.
The Connect Vertices form includes the following specifications.
Vertices  specifies the vertices to be connected. 
All Pick 

Real  specifies that the vertex that results from the connection of vertices is a real vertex. (NOTE: To obtain a real vertex from the connection of two or more real vertices, the specified vertices must be coincident.) 
Virtual (Forced)  specifies the following characteristics for the vertex that results from the connection of vertices:

Virtual (Tolerance)  specifies the following characteristics for the vertex that results from the connection of vertices:

Real and Virtual (Tolerance)  specifies the following sequence of operations:

Tolerance  specifies the maximum allowable distance (absolute units) between vertices to be connected. 
Shortest Edge %  specifies the maximum allowable distance (percent of shortest edge) between vertices to be connected. 
Highlight shortest edge  highlights the shortest edge that exists in the current model. 
Preserve first vertex location  creates the new vertex at the location of the first vertex listed in the Vertices list. 
The Disconnect About Real Vertex operation (vertex disconnect command) disconnects entities that share a common vertex.
When you disconnect edges, faces, and/or volumes about a common vertex, GAMBIT creates a separate vertex for each entity to which the specified vertex is connected. As a result, the entities are disconnected and can be treated (for example, moved or aligned) independently with respect to each other.
As an example of the vertex disconnection procedure, consider the configuration shown in Figure 229, in which face.1 and edge.5 share a common vertex (vertex.4). If you disconnect the topology about vertex.4, GAMBIT creates a new vertex (vertex.6) that is coincident with vertex.4 and assigns it as an endpoint of edge.5. As a result, face.1 and edge.5 are disconnected from each other.
Figure 229: Disconnecting entities about a common vertex
NOTE: GAMBIT does not allow you to disconnect topology around a vertex that constitutes part of an individual face or volume. For example, you cannot disconnect edge.1 and edge.2 about vertex.1 in Figure 229, because vertex.1 constitutes one corner of a single topological entity—that is, face.1. 
To open the Disconnect About Real Vertex form (see below), click the Disconnect command button on the Geometry/Vertex subpad.
The Disconnect About Real Vertex form includes only a list box that allows you to specify the vertex about which the topology is to be disconnected.
The Modify Vertex Color/Label command button allows you to perform two operations.
Symbol  Operation  Description 
Modify Vertex Color  Changes the color of one or more vertices as displayed in the graphics window  
Modify Vertex Label  Changes a vertex label 
The following sections describe the procedures and specifications required to execute the operations listed above.
The Modify Vertex Color operation (vertex modify command) changes the displayed color of one or more vertices. To modify the Geometry color specification on the Modify Vertex Color form, click the color bar located immediately to the right of the Geometry check box on the Modify Vertex Color form. When you do so, GAMBIT opens the Set Color form. The Set Color form allows you to select a color from a preset list of available colors. (See "Using the Set Color Form," below.)
To open the Modify Vertex Color form (see below), click the Modify Color command button on the Geometry/Vertex subpad.
The Modify Vertex Color form includes the following specifications.
Vertices  specifies one or more vertices the color of which is to be modified. 
Color:  
Geometry  specifies modifying the color of the currently specified vertices. 
To open the Set Color form (see below), click the Geometry color bar on the Modify Vertex Color form.
The Set Color form includes the following specifications.
Color name  specifies the color by name. 
Colors:  allows you to select a color from a list of available colors. GAMBIT displays the currently selected color as a color band located immediately above the Colors: scroll list. 
The Modify Vertex Label operation (vertex modify command) changes the label associated with any vertex.
To open the Modify Vertex Label form (see below), click the Modify Label command button on the Geometry/Vertex subpad.
The Modify Vertex Label form includes the following specifications.
Vertex  specifies the vertex to be modified. 
Label  specifies a new label for the vertex. (See Section 2.1.1). 
The Move/Copy/Align Vertices command button allows you to perform two operations.
Symbol  Operation  Description 
Move/Copy Vertices  Moves and copies vertices  
Align Vertices  Aligns vertices and connected geometry with existing topological entities 
The following sections describe the procedures and specifications required to execute the operations listed above.
The Move/Copy Vertices operation (vertex copy, vertex move, vertex cmove, vertex reflect, vertex creflect, vertex scale, and vertex cscale commands) repositions and/or creates copies of vertices. For a description of the procedures and specifications required to move and/or copy entities, see "Moving an Entity" and "Copying an Entity," respectively, in Section 2.1.4.
To open the Move/Copy Vertices form (see below), click the Move/Copy command button on the Geometry/Vertex subpad.
For a complete description of the specifications available on the Move/Copy Vertices form, see "Using Move/Copy Forms" in Section 2.1.4.
The Align Vertices operation (vertex align command) repositions a set of one or more vertices with respect to a set of translation, rotation, and planealignment vertices. When you align a vertex, GAMBIT translates the vertex according to the specifications on the Align Vertices form. You cannot rotate or planealign a vertex because vertices are zerodimensional entities. (For a general description of the procedure and specifications required to align an entity, see "Aligning an Entity," in Section 2.1.4.)
To open the Align Vertices form (see below), click the Align command button on the Geometry/Vertex subpad.
For a complete description of the specifications available on the Align Vertices form, see "Using Align Forms" in Section 2.1.4.
The Convert Vertices (Nonreal to Real) operation (vertex convert command) converts one or more nonreal (faceted and/or virtual) vertices to real vertices. The topology and any existing mesh associated with the converted vertices are preserved in the conversion process.
To open the Convert Vertices (Nonreal to Real) form (see below), click the Convert command button on the Geometry/Vertex subpad.
The Convert Vertices (Nonreal to Real) form includes the following specifications.
Vertices  specifies which nonreal vertices are to be converted to real vertices. 
All Pick 

The Summarize/Check/Query Vertices and Total Entities command button lets you perform the following operations.
The following sections describe the procedures and specifications required to execute the operations listed above.
The Summarize Vertices operation (vertex summarize command) displays vertex summary information in the Transcript window. The summary information includes the vertex name, mesh status, and the coordinates of the vertex relative to the global coordinate system.
To open the Summarize Vertices form (see below), click the Summarize command button on the Geometry/Vertex subpad.
The Summarize Vertices form includes the following specifications.
Vertices  specifies one or more vertices for which information is to be summarized in the Transcript window. 
All Pick 

The Check Vertices operation (vertex check command) assesses the topological and/or geometrical validity of vertices in the model and summarizes the results in the Transcript window.
When you execute the Check Vertices command, GAMBIT checks the model to determine its validity with respect to either or both of the following types of characteristics:
NOTE (1): Failure of the topology and/or geometry check for any vertex in the model constitutes a serious problem for the model as a whole. GAMBIT does not currently include any tools that allow you to repair problems that cause failures of topology or geometry checks for vertices. 
NOTE (2): GAMBIT can automatically check the validity of all input and output (created) entities for any geometry operation and display warning or error messages in the Transcript window for any entity that fails the check(s). The automaticchecking behavior is specified by means of the GEOMETRY.GENERAL.CHECK_LEVEL default variable, which can be set to any of the following values.

Topological validity is an assessment of the underlying organization of the model—for example, the correct associations between a face entity and the edges that comprise its boundaries or between entities that are associated with each other by virtue of a virtualgeometry, guesthost relationship.
For any specified vertex, the Check Vertices topology check operation examines the model to ensure that the vertex meets the following criteria:
Geometrical validity is an assessment of the model with respect to proximity and shape characteristics—such as the distances between connected edges and/or the mathematical continuity of model curves and surfaces. The Check Vertices geometry check criteria are as follows:
To open the Check Vertices form (see below), click the Check command button on the Geometry/Vertex subpad.
The Check Vertices form includes the following specifications.
Vertices  specifies the vertices to be included in the checking operations. 
All Pick 

Check Topology  specifies a topology check on the selected vertices. 
Check Geometry  specifies a geometry check on the selected vertices. 
The Query Vertices operation (no corresponding commandline command) allows you to identify the locations and/or names of individual vertices or subsets of vertices in the model.
When you execute the Query Vertices command, GAMBIT opens the Query Vertices form, which lists all existing vertices in the model. You can use the Query Vertices form to identify individual vertices, one at a time, or subsets of vertices by means of a label filter.
You can use the Query Vertices form to perform the following vertex identification tasks:
To identify the label of a vertex with a known location, select (pick) the vertex in the graphics window. GAMBIT highlights the vertex label in the query list.
The Query Vertices form includes a Filter text box that allows you to quickly identify individual vertices or subsets of vertices the labels of which contain a common string. To identify an individual vertex, input its label in the Filter text box. To identify a subset of vertices, input the common string value and include one or more wildcard characters (*). (NOTE: In either case, you must press Enter to complete the Filter string input.)
For example, if you input the Filter string "vertex.2", GAMBIT highlights only vertex.2 in the query list and graphics window. If you input the Filter string "vertex.2*", GAMBIT highlights all vertices the labels of which begin with "vertex.2"—that is, vertex.2, vertex.20, vertex.21, ..., vertex.29; vertex.200, vertex.201, ..., vertex.299, and so on.
To open the Query Vertices form (see below), click the Query command button on the Geometry/Vertex subpad.
The Query Vertices form includes the following specifications.
Label Names  contains the names of all vertices currently existing in the model. Vertices corresponding to highlighted names are displayed in red in the graphics window. 
Filter  specifies the filter text string. 
Label  specifies that labels corresponding to highlighted vertex names are displayed in the graphics window. 
The Total Entities operation (list totals command) displays in the Transcript window the total number of geometry and/or mesh entities that currently exist in the model. For example, if you select only the Geometry entities option on the Total Entities form and click Apply, GAMBIT displays in the Transcript window the total numbers of vertices, edges, faces, volumes, groups, and coordinate systems that currently exist in the model.
To open the Total Entities form (see below), click the Total command button on the Geometry/Vertex subpad.
The Total Entities form includes two check boxes that allow you to specify the types of entities the totals of which are displayed in the Transcript window. It includes the following options.
The Delete Vertices operation (vertex delete command) deletes one or more vertices from the model. The operation is subject to the following restrictions:
If you delete a virtual vertex, GAMBIT deletes all virtual hierarchy that is associated with the vertex and is not associated with any other entities in the model.
To open the Delete Vertices form (see below), click the Delete command button on the Geometry/Vertex subpad.
The Delete Vertices form includes the following specifications.
Vertices  specifies one or more vertices to be deleted. 
All Pick 
