Fluent Inc. Logo return to home
next previous contents index

3.4 Using the Global Control Toolpad

The Global Control toolpad (Figure 3-8 and below) allows you to control the layout and operation of the graphics window as well as the appearance of the model as displayed in any individual quadrant. In addition, the Global Control toolpad includes an Undo/Redo button that undoes the most recently executed GAMBIT operation or re-executes the most recently undone operation.

The Global Control toolpad contains two types of command buttons:

Global Control toolpad

The quadrant command buttons allow you to specify whether or not any or all of the quadrants are enabled or disabled with respect to changes in their appearance. The control command buttons allow you to perform the following operations:

The following sections describe the operation and use of both types of command buttons.


3.4.1 Quadrant Command Buttons

Quadrant command buttons (window activate and window deactivate command-line commands) allow you to enable and disable any or all of the graphics-window quadrants with respect to changes in the model appearance. From left to right on the Global Control toolpad, the quadrant command buttons correspond to the following quadrants:

Each quadrant command button toggles its corresponding quadrant between the enabled and disabled states. Enabled quadrants are displayed in red on their corresponding command buttons. Disabled quadrants are displayed in gray.

To enable a disabled quadrant or disable an enabled quadrant, click the corresponding quadrant command button. To enable all quadrants, click All.


3.4.2 Control Command Buttons

Control command buttons allow you to specify the appearance of the graphics window itself and of the model as viewed in any individual quadrant. In addition, the Undo/Redo control command button undoes the most recently executed GAMBIT operation or re-executes the most recently undone operation. The Global Control toolpad contains the following control command buttons.

Symbol
Command Description
Fit to Window Scales the graphics display to fit within the boundaries of the enabled quadrants

Select Pivot Specifies the location of the pivot point for model movement by means of the mouse
Select Preset Configuration Arranges the graphics window to reflect one of six preset configurations


Modify Lights

Annotate

Specify Label Type

Specifies the direction and magnitude of light on the model

Allows you to add arrows, lines, and text to the graphics display

Specifies the types of labels displayed by means of the Specify Display Attributes form


Undo

Redo

Undoes the most recently executed GAMBIT operation

Redoes the most recently undone GAMBIT operation

Orient Model Applies a preset model orientation to all active quadrants, orients the model with respect to a specified face or vector, and stores commands related to the current orientation in a journal file
Specify Display Attributes Allows you to specify the characteristics of the graphics display
Render Model Specifies whether the model is displayed in a wireframe, shaded, or hidden perspective

Specify Color Mode Specifies whether model colors are based on entity types or on connectivity
Examine Mesh Allows you to interactively view an existing mesh.

The following sections describe the function and use of the command buttons listed above.


Fit to Window

The Fit to Window command button (window full command-line command) scales the graphics display to fit in each of the enabled quadrants.


Select Pivot

The Select Pivot command button allows you to change the pivot point around which the model turns when you rotate and/or revolve it using the left and right mouse buttons (see "Rotate the Model (Left-drag)" and "Revolve/Zoom the Model (Right-drag)," above). (NOTE: The Select Pivot graphics control options can also be invoked by means of the anchor and noanchor key­words on the graphics command-line command.)

GAMBIT allows you to specify either of two points about which to pivot the model.

Symbol Pivot Point
Center of viewing volume
(graphics command, noanchor keyword)
User-specified point
(graphics command, anchor keyword)

To define a user-specified pivot point, click the Select Pivot command button to display the user-specified point symbol, then left-click at the selection point in the graphics window to identify the new pivot point location. GAMBIT locates the pivot point according to the following hierarchy of rules:

  1. If the selection point intersects one or more coordinate systems, GAMBIT locates the pivot point at the coordinate system closest to the viewer.
  2. If the selection point intersects one or more vertices, GAMBIT locates the pivot at the vertex closest to the viewer.
  3. If the selection point intersects one or more edges, GAMBIT locates the pivot in reference to the selection point and the nearest edge. GAMBIT uses either the point of intersection as the anchor point or the tangent to the edge at that point as an axis of rotation.
  4. If the selection point intersects one or more faces, GAMBIT locates the pivot at the point of intersection with the closest face.
  5. If the selection point does not intersect any model components, GAMBIT sets the center of the viewing volume as the pivot point.
To restore the pivot point to its default (quadrant centroid) location, click Select Pivot command button to display the quadrant centroid symbol.


Select Preset Configuration

The Select Preset Configuration command button allows you to modify the overall configuration of the graphics window and the orientation of the model as displayed in the enabled quadrants.

To open the menu of preset configuration options, right-click the Select Preset Configuration button. The preset configuration options include the following configurations and orientations.

Option Description
Displays all four quadrants and applies the following orientations to the currently enabled quadrants.
Quadrant Orientation
Upper left -y
Upper right Isometric
Lower left -z
Lower right -x

Displays all four quadrants and applies an isometric view in each currently enabled quadrant.
Expands the upper left quadrant to fill the graphics window.
Expands the upper right quadrant to fill the graphics window.
Expands the lower left quadrant to fill the graphics window.
Expands the lower right quadrant to fill the graphics window.


Modify Lights

When you click the Modify Lights command button, GAMBIT opens the Modify Lights form. The Modify Lights form allows you to customize the appearance of model shading.

Using the Modify Lights Form

The Modify Lights form (see below) allows you to specify the direction and brightness of eight different light sources used to determine model shading. Each light source is represented on the Modify Lights form by one of eight colors: white, cyan, magenta, blue, yellow, green, red, and black.

The Modify Lights form consists of the following components:

Status Buttons

The Modify Lights form contains eight sets of status buttons corresponding to each of the eight light sources. Each set of status buttons includes the following buttons:

Each Light command button toggles the state of its associated light source between the active (On) and inactive (Off) states. The Ambient and Distant radio buttons constitute mutually exclusive selectors that allow you to specify whether a specific light source is located close to (Ambient) or distant from (Distant) the model.

Orientation Globe

The Modify Lights orientation globe consists of a wireframe sphere upon which are located eight colored circles-each of which is displayed as either solid or hollow. Each circle represents one of the eight light sources. Solid circles represent light sources that are currently specified as On; hollow circles represent light sources that are currently specified as Off.

To reposition any of the eight light sources relative to the model (center of globe) left-click its corresponding circle on the orientation globe and left-drag the circle to the new location. To drag the light source to the side of the globe farthest from the viewer, drag it to the edge of the globe, then back toward the middle. The light source is located on the far side of the globe when it is located on the dashed portion of a circumferential line.

NOTE: If you reposition lights that are Ambient or Off, GAMBIT does not change model shading.


Annotate

When you click the Annotate command button, GAMBIT opens the Annotate form. The Annotate form allows you to add annotation objects such as arrows, lines, or text to any individual graphics window quadrant and to modify or delete such objects.

GAMBIT allows you to perform the following operations with respect to annotation objects.

Operation Description
Add Creates a new object in the graphics window
Modify Modifies an existing object
Delete Deletes an existing object
Delete all Deletes all existing objects

Adding an Annotation Object

GAMBIT allows you to add the following types of annotation objects:

When you Add an annotation object to a graphics window quadrant, GAMBIT creates the object and fixes its position and orientation at an anchor point relative to the quadrant itself. Annotation objects do not move when you translate, rotate, or zoom in or out on the model. To specify the anchor point, left-click the graphics window at the anchor point.

If you resize a quadrant that contains annotation objects, GAMBIT maintains the positions of the object anchor points relative to the original proportions of the quadrant. However, GAMBIT does not alter Text or Title characters when you resize a quadrant, therefore, the characters retain their original size.

Arrow Object

To add an Arrow annotation object, perform the following steps:

Step Description
1 Select the Add radio button on the Annotate form.
2 Select the Object:Arrow option.
3 Specify the object Color and Width.
4 Shift-left-click the graphics window at the point at which the tail of the arrow is to be located, and release the mouse button.
5 Shift-left-click again in the graphics window, and Shift-left-drag the mouse pointer to the point at which the head of the arrow is to be located.
6 Click Apply on the Annotate form (or Shift-right-click in the graphics window).

NOTE: To create an arrow consisting of more than one line segment, repeat Step 5 for each endpoint of each intermediate segment. When you Shift-right-click to Apply the arrow annotation object, GAMBIT creates an arrow defined by the series of line segments and possessing a single arrowhead located at the last point selection point.

Line Object

To add a Line annotation object, follow the general directions outlined above with respect to adding an Arrow object but select the Object:Line in lieu of the Object:Arrow option in Step 2. The Line and Arrow annotation objects differ only in that the Line object does not include an arrowhead.

Text Object

To add a Text annotation object, perform the following steps:

Step Description
1 Select the Add radio button on the Annotate form.
2 Select the Object:Text option.
3 Specify the object Color and Size, and input the alphanumeric Text associated with the object.
4 Shift-left-click in the graphics window, and drag the text to its final location.
5 Click Apply on the Annotate form (or Shift-right-click in the graphics window).

NOTE: When you select the Object:Text option, GAMBIT displays a pushbutton labeled "Title" to the right of the Object option button. If you click the Title pushbutton, GAMBIT automatically fills the Text input field with the title of the current GAMBIT session.

Modifying an Annotation Object

To modify an annotation object, perform the following steps:

Step Description
1 Select the Modify radio button on the Annotate form.
2 Pick the object to be modified. (NOTE: To unpick a picked object, Shift-middle-click on the object.)
3 Specify the modifications by means of the Object and Properties fields on the Annotate form. (NOTE: To change the position of an object within its quadrant, Shift-left-drag or Shift-middle-drag the object to its new location.)
4 Click Apply on the Annotate form (or Shift-right-click in the graphics window).

Deleting an Annotation Object

To delete an annotation object, perform the following steps:

Step Description
1 Select the Delete radio button on the Annotate form.
2 Shift-left-click the object to be deleted.
3 Click Apply on the Annotate form (or Shift-right-click in the graphics window).

Deleting All Existing Annotation Objects

To delete all existing annotation objects, perform the following steps:

Step Description
1 Select the Delete all radio button on the Annotate form.
2 Click Apply on the Annotate form (or Shift-right-click in the graphics window).

Using the Annotate Form

The Annotate form (see below) allows you to add, modify, or delete annotations to the graphics display. To open the Annotate form, click the Annotate command button on the Global Control toolpad.

The Annotate form includes the following options and specifications.

Operation:
Add specifies the addition of an annotation object.
Modify specifies the modification of an existing annotation object.
Delete specifies the deletion of an existing annotation object.
Delete all deletes all existing annotation objects.
Object: (active for Add and Modify options only)
Arrow
Line
Text
specifies the type of annotation to be added or modified.
Properties:
Color: specifies the color of the annotation.

When you click the Color bar (located immediately to the right of the Color: heading), GAMBIT opens the Set Color form, which allows you to specify the annotation color. For instructions concerning the use of the Set Color form, see "Using the Set Color Form," below.

Width: (Arrow and Line options only) specifies the thickness of the Arrow or Line annotation object.
Text: (Text option only) specifies the wording of the annotation. (NOTE: When you select the Object:Text option, GAMBIT displays a pushbutton labeled "Title" to the right of the Object option button. If you click the Title pushbutton, GAMBIT automatically fills the Text input field with the title of the current GAMBIT session.)

Using the Set Color Form

The Set Color form allows you to specify the color of an annotation object. To open the Set Color form (see below), click the Color bar on the Annotate 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.

To select a color, left-click the color in the scroll list. GAMBIT displays the currently selected color on a color band located immediately above the Colors scroll list.

NOTE: You must click Apply to apply the color specification and close the form.


Specify Label Type

When you click the Specify Label Type command button, GAMBIT opens the Specify Label Type form. The Specify Label Type operation (label command-line command) allows you to specify the types of labels that are displayed when you display labels using the Specify Display Attributes form (see "Specify Display Attributes," below).

GAMBIT allows you to specify the display of any or all of the following types of labels.

Label Type Description Example
Regular Entity face.3
Scheme Meshing schemes scheme = pave
Interval Edge mesh intervals int = 15
Boundary Layer Boundary layers b_layer = b_layer.5
Size Function Size functions sf = sfunc.1
Boundary Type Boundary-type zone specifications btype = WALL
Continuum Type Continuum-type zone specifications ctype = FLUID

To display a label, you must specify the label type, by means of the Specify Label Type form, and activate labels for the entity (or entities) of interest, by means of the Specify Display Attributes form. For example, to display the numbers of mesh intervals for all edges in the model, you must select the Interval options on the Specify Label Type form, then activate labels for all edges by means of the Specify Display Attributes form.

NOTE (1): If the Label option on the Specify Display Attributes form is On, changes made on the Specify Label Type form affect the model display as soon as they are specified.
NOTE (2): The Specify Label Type form specifications do not affect coordinate system labels.

Using the Specify Label Type Form

The Specify Label Type form (see below) allows you to specify the types of labels that are displayed by means of the Specify Display Attributes form. To open the Specify Label Type form, click the Label Type command button on the Global Control toolpad.

The Specify Label Type form consists of a field of check boxes that allow you to specify the display of the following label types (see above):


Undo

The Undo command (undo command-line command) undoes GAMBIT operations in reverse order relative to their sequence of execution.

Overview

When you click the Undo command button, GAMBIT reverses the most recently executed operation. For example, if you create a vertex and click Undo, GAMBIT deletes the vertex.

Multiple Undo Operations

As you create and/or mesh a model, GAMBIT maintains and updates an "undo" list-that is, a first-in/last-out sequential list of Geometry, Mesh, Zones, Tools and Global Control commands performed during the modeling session. When you execute the Undo command, GAMBIT reverses the most recently executed operation and removes it from the undo list. If you execute the Undo command a second time, GAMBIT reverses and removes from the undo list the operation that you performed immediately prior to the most recently executed operation-and so on. For example, if you create and mesh a cylindrical volume, then click Undo, GAMBIT removes the mesh from the volume. If you click Undo a second time, GAMBIT deletes the volume.

By default, GAMBIT maintains 10 undo levels--that is, the undo list contains the 10 most recently executed operations. To increase or decrease the number of operations retained in the undo list, modify the GAMBIT UNDO default variable by means of the Edit Defaults form (see Section 4.2.4).

NOTE: Increasing the number of undo levels necessarily increases the amount of disk space required by the GAMBIT program.


Redo

The Redo command (redo command-line command) reverses the most recently executed GAMBIT Undo operation.

Overview

When you click the Redo command button, GAMBIT reverses the most recently executed Undo operation. For example, if you create a vertex and click Undo, GAMBIT deletes the vertex. If you then click Redo, GAMBIT restores the vertex to the model.

Multiple Redo Operations

GAMBIT allows you to Redo multiple-operation sequences that are undone by means of the Undo operation. For example, if you create and mesh a cylindrical volume, then click Undo, GAMBIT removes the mesh from the volume. If you click Undo a second time, GAMBIT deletes the volume. If you then click Redo , GAMBIT restores the volume, and if you click Redo a second time, GAMBIT restores the mesh.

By default, GAMBIT allows you to undo the 10 most recently executed operations and to Redo the 10 most recently executed Undo operations. To increase or decrease the number of operations that can be undone and/or redone, modify the GAMBIT UNDO default variable by means of the Edit Defaults form (see Section 4.2.4).

NOTE: Increasing the number of undo levels necessarily increases the amount of disk space required by the GAMBIT program.


Orient Model

The Orient Model command button (window orient and window previous command-line commands) allows you to apply a preset model orientation to all currently enabled quadrants, to orient the model with respect to a specified face or vector, and to store commands related to the current orientation in a journal file.

To open the menu of Orient Model options, right-click the Orient Model command button. The Orient Model menu includes the following options.

Option Description
Displays the model as viewed in the -x direction.
Displays the model as viewed in the +x direction.
Displays the model as viewed in the -y direction.
Displays the model as viewed in the +y direction.
Displays the model as viewed in the -z direction.
Displays the model as viewed in the +z direction.
Displays an isometric view of the model.
Reverses the orientation of the model as currently displayed in each quadrant.
View Face/Vector option—orients the model in a direction either normal to an existing face or defined by a vector (see "Using the View Face/Vector Form," below).
Displays the model according to its previous orientation and configuration. (NOTE: This operation is identical to the double-middle-click in the graphics window (see "Show Previous View (Double-middle-click)," above).
Saves the commands corresponding to the current model orientation and configuration to the session journal text file. (NOTE: This operation is identical to the double-right-click in the graphics window (see "Journal View (Double-right-click)," above).


Using the View Face/Vector Form

The View Face/Vector option allows you to view the model from a direction normal to any one of the model faces or in relation to a specified vector. When you select the View Face/Vector on the Orient Model menu, GAMBIT opens the View Face/Vector form (see below). The View Face/Vector form allows you to specify the face toward which or vector along which the model is to be viewed.

The View Face/Vector form includes the following options:

(quadrant command buttons) enable or disable any or all quadrants with respect to changes in model appearance.
Orientation:
Normal to Face
Along Vector
allows you to specify one of two options for orienting the model.
  • Normal to Face orients the model normal to a selected face
  • Along Vector orients the model in the direction of a specified vector
The following sections describe each of the options.

Normal to Face Option

The Normal to Face option allows you to orient the model in the direction normal to a specified face. For instructions in specifying the face that defines the view direction, see "List Boxes," above. (NOTE: When you specify the Normal to Face option, GAMBIT scales the model to fit in the enabled quadrants when it reorients the model.)

Along Vector Option

The Along Vector option allows you to view the model in the direction of a specified vector. GAMBIT orients the model so that the specified vector is normal to the plane of the screen.

When you select the Along Vector option, GAMBIT displays a Define command button immediately below the Along Vector button. To specify the vector in the direction of which the model is to be viewed, click the Define command button to open the Vector Definition form. (See "Using the Vector Definition Form," below.)

Using the Vector Definition Form

The Vector Definition form (see below) allows you to define a vector for use in GAMBIT operations such as model orientation or the specification of axes of rotation (for example, see Section 2.1.4 of the GAMBIT Modeling Guide). To define a vector, you must specify information regarding its magnitude and direction, as well as the location of its origin. GAMBIT provides several options for specifying such information).

The Vector Definition form includes the following specifications.

Active Coordinate System Vector displays the coordinates of the origin (Start) and tip (End) for the current vector definition. (NOTE: The Start and End locations are always defined in terms of the active coordinate system.)
Magnitude specifies the magnitude of the vector. (NOTE: If you input a negative value for the Magnitude parameter, GAMBIT reverses the direction of the vector relative to its Method-option definition but does not change the location of the vector origin.)
Method:
Coord. Sys. Axis
Edge
2 Points
2 Vertices
Screen View
specifies the method to be used for specifying the vector endpoints. The available options are as follows:
  • Coord. Sys. Axis—defines the vector with respect to one of the coordinate axes
  • Edge—defines the vector by means of the endpoints of an existing edge
  • 2 Vertices—defines the vector by means of two existing vertices
  • 2 Points—defines the vector by means of two specified locations (points) in space
  • Screen View—defines the vector relative to the model orientation currently displayed in the graphics window

The specifications available in the lower section of the Vector Definition form vary according to Method option. The following subsections describe specifications associated with each of the options listed above.

Specifying a Vector Defined by a Coordinate System Axis

When you select the Coord. Sys. Axis option, GAMBIT defines the vector with respect to a coordinate axis. To define the vector, you must specify the following information:

For this option, the lower portion of the Vector Definition form appears as shown above and includes the following specifications.

Coordinate Sys. specifies the reference coordinate system for the vector.
Direction: contains radio buttons that allow you to specify the axis and direction to be used in the vector definition. The available options are as follows:
  • XPositive or Negative
  • YPositive or Negative
  • ZPositive or Negative
For example, if you specify c_sys.1 in the Coordinate Sys. list box and select the Z Negative orientation option, GAMBIT defines a vector that points in the negative direction along the z axis of c_sys.1 with an origin at the origin of c_sys.1.

Specifying a Vector Defined by a Model Edge

When you select the Edge option, GAMBIT defines the vector by means of the endpoint vertices of an existing edge. For this option, the lower portion of the Vector Definition form appears as shown below and includes the following specification.

Vector Definition form—Edge option specification

Edge specifies an edge the endpoints of which define the origin, magnitude, and direction of the vector.

The origin of the vector is located at the edge start endpoint vertex, and its tip is located at its end endpoint vertex. To reverse the direction of the vector, either middle-click the edge to reverse its sense or input a negative value for the Magnitude specification. (For a description of edge start and end vertices and the meaning of edge sense, see Section 2.3.1 of the GAMBIT Modeling Guide.)

Specifying a Vector Defined by Two Vertices

When you select the 2 Vertices option, GAMBIT defines the vector by means of the locations of two existing vertices. For this option, the lower portion of the Vector Definition form appears as shown below and includes the following specifications.

Vector Definition form—2 Vertices option specifications

Vertices: contains two list boxes that specify vertices defining the origin (Start) and tip (End) of the vector. (NOTE: To reverse the direction of the vector, either switch the Start and End vertex specifications or input a negative value for the Magnitude specification.)

Specifying a Vector Defined by Two Points

When you select the 2 Points option, GAMBIT defines the vector by means of two point locations. For this option, the lower portion of the Vector Definition form appears as shown below and includes the following specifications.

Vector Definition form—2 Points option specifications

Coordinate Values: contains two radio buttons that specify the point associated with the values currently displayed in the lower part of the form. The options, Point 1 and Point 2, specify the positions of the vector origin and tip, respectively. (NOTE: To reverse the direction of the vector, either switch the specifications for the two points or input a negative value for the Magnitude specification.)
Coordinate Sys specifies the coordinate system of reference for the points that define the vector.
Type
Cartesian
Cylindrical
Spherical
specifies the type of coordinate system to be used in the current point specification.
Global | Local specifies the location of the point with respect to either the Global or Local system.

Specifying a Vector Defined by the Current Screen View

When you select the Screen View option, GAMBIT defines the vector relative to the current orientation of the model in the graphics window. For this option, the lower portion of the Vector Definition form appears as shown below and includes the following specifications.

Vector Definition form—Screen View option specifications

Direction: contains a group of paired radio buttons that allow you to specify the vector definition relative to the currently displayed orientation of the model in the graphics window. The six Direction options are as follows:
  • PiercingOut or In
  • HorizontalRight or Left
  • VerticalUp or Down
For example, if you select the Piercing--In option and left-click on a graphics window quadrant, GAMBIT defines a vector pointing directly into the screen with an origin located in the center of the quadrant.


Specify Display Attributes

When you click the Specify Display Attributes command button, GAMBIT opens the Specify Display Attributes form (see below). The Specify Display Attributes operations (window modify command-line command) allow you to customize the appearance of the model in any currently enabled quadrant.

Using the Specify Display Attributes Form

The Specify Display Attributes form allows you to customize the appearance of the model in any or all of the graphics windows quadrants. It includes the following options.

(quadrant command buttons) enable or disable any or all quadrants with respect to changes in model appearance.

The middle section of the Specify Display Attributes form allows you to select individual model entities or entire entity types for display specification. The available entity-type options include groups (Groups), volumes (Volumes), faces (Faces), edges (Edges), vertices (Vertices), boundary layers (B. Layers), and coordinate systems (C. Sys).

Specifying Display Attributes—Groups Example

The options available for each entity type are identical to those for model groups—which are as follows.

Groups applies the specified display attributes to any or all groups in the model.
All
Pick
allows you to select the model groups to which the specified display attributes apply.
  • All specifies all groups in the model
  • Pick specifies groups selected by means of the Group list box (see below). (NOTE: If you pick a group in the graphics window or click in the Group list box, GAMBIT automatically selects the Pick option.)
Groups allows you to select specific groups to which to apply the display attributes.
Visible specifies the visibility of the selected groups. The visibility options are visible (On) or invisible (Off).
Label specifies the visibility of labels for the selected groups. The visibility options are visible (On) or invisible (Off). To select the types of labels to be displayed, use the Specify Label Type command on the Global Control toolpad.
Silhouette specifies the visibility of silhouettes for the selected groups. The visibility options are visible (On) or invisible (Off). Silhouettes display outlines of surfaces that do not possess edges—for example, the curved surfaces of cylinders and spheres.
Mesh specifies the visibility of the mesh. The visibility options are visible (On) or invisible (Off).
Render specifies the general appearance of the selected visible groups by means of an option button. The general-appearance options are:
  • Wire—wireframe model view displays a wireframe view of the selected groups.
  • Shade—shaded model view displays a three-dimensional shaded view of the selected groups.
  • Hidden—renders invisible all hidden lines. Hidden lines are those concealed behind other entities in the current model orientation.
Lower topology includes lower topology for the selected entity (or entities) in the application of the current display specifica­tions. For example, if you select a volume and specify the Visible:Off and Lower topology options, the volume disappears completely from the graphics window. If you do not select the Lower topology option, however, GAMBIT removes the volume from the graphics window but continues to display the faces that comprise the boundary surfaces for the volume. Similarly, if you select a face and specify the Label:On and Lower topology options, GAMBIT displays the labels for the selected face and all of its lower-topology entities (edges and vertices). If you do not select the Lower topology option, GAMBIT displays only the label for the selected face.


Render Model

The Render Model command (window modify command-line command) allows you to render the model as either wireframe, shaded, or hidden. The symbol displayed on the Render Model command button indicates its current function. To change the function of the button, right-click it to open the menu of available functions, then select the desired function from the menu. When you select a function from the menu, GAMBIT automatically renders the model according to the selected function.


Specify Color Mode

The Specify Color Mode command button allows you to toggle between two modes of coloring vertices and edges displayed in the graphics window. The two color modes are:

Topology Mode

In the topology color mode, GAMBIT displays vertices and edges in colors that conform to the currently defined geometry color conventions. The default color conven­tions are as follows.

Entity Color
Vertex white
Edge yellow
Face cyan
Volume green
Group darkgreen

The displayed color for any vertex or edge is that of the highest topological entity to which it belongs. For example, a standalone vertex is displayed as white, but a vertex that constitutes the corner of a cubic volume is displayed as green. Similarly, a standalone edge is displayed as yellow, but an edge that constitutes part of a face boundary is displayed as cyan.

NOTE: You can change any or all of the default color conventions listed above by means of the GEOMETRY tab on the Edit Defaults form (see "Using the Edit Defaults Form" in Section 4.2.4).

Connectivity Mode

In the connectivity color mode, GAMBIT displays vertices and edges in colors that conform to the currently defined connectivity color conventions. The default connectivity color conventions are as follows.

Number of Connections Color
0 white
1 orange
2 dodgerblue
3 or more magenta

The displayed color for any vertex or edge depends on the number of entities to which it is connected. For example, a standalone vertex is displayed as white but a vertex that serves as a common endpoint for two edges is colored orange. Similarly, lone edges are displayed as white, but an edge that is shared by two adjacent faces is displayed as dodgerblue.

If two coincident entities differ in the degree of their connectivity to other entities in the model, GAMBIT displays the color corresponding to the least-connected entity. For example, if a vertex is coincident with the corner vertex of a four-sided face, GAMBIT displays a white vertex at the location of coincidence.

NOTE (1): GAMBIT determines connectivity coloration for any entity based on the number of sides of the entity that are connected to higher entities. For example, if you create a face that includes a dangling edge, GAMBIT assigns the dan­gling edge a connectivity color of dodgerblue because the face itself exists on two separate sides of the edge.
NOTE (2): You can change the default connectivity color conventions by means of the GEOMETRY tab on the Edit Defaults form (see "Using the Edit Defaults Form" in Section 4.2.4).


Examine Mesh

When you click the Examine Mesh command button, GAMBIT opens the Examine Mesh form (see below). The Examine Mesh form allows you to display an existing mesh and to customize the characteristics of the mesh display.

To display a mesh by means of the Examine Mesh form, you must specify two major sets of parameters:

The Display Type parameters determine which mesh elements are visible when the mesh is displayed. The Display Mode parameters determine the visual appearance of elements that are displayed.

NOTE: GAMBIT does not automatically update the graphics display when you modify specifications on the Examine Mesh form. To update the graphics display, you must click the Update pushbutton located at the bottom of the form. The Update pushbutton label is displayed in red lettering whenever the display needs to be updated to reflect the current Examine Mesh specifications.

Specifying the Display Type

There are three general Display Type specifications on the Examine Mesh form:

The domain specification allows you to define which region of the mesh is displayed. The element-type specification determines which element shapes are included in the group of displayed elements. The quality-type specification determines the quality criterion that is used to color displayed elements and/or to define which elements are displayed.

The following sections describe each of the specifications listed above.

Specifying the Domain

The domain specification consists of the following options:

The Plane and Sphere options allow you to display mesh elements located relative to a planar or spherical cut through the mesh. The Range option allows you to display only those mesh elements the quality of which falls within specified limits with respect to a designated quality criterion.

The following sections describe the each of the options listed above and illustrate their relative effects on the mesh display for the elliptical cylinder shown in Figure 3-14. (NOTE: In this example, the cross section of the cylinder is elongated with respect to the x axis, and the cylinder is aligned with the z axis.)

Figure 3-14: Meshed elliptical cylinder

Plane Option

When you select the Plane option, GAMBIT displays a plane cut through the mesh. To customize the plane cut, you must specify two parameters:

The Cut Type specification determines whether GAMBIT displays a zero-thickness plane cut through the mesh or an array of mesh elements defined by their position with respect to the cutting plane. The Cut Orientation specification allows you to align the cutting plane with one of the three planes of the active coordinate system and to specify the position of the cutting plane.

Specifying the Cut Type

To specify the Cut Type, you must select one of the following options:

Display cut Option

When you select the Display cut option, GAMBIT displays a zero-thickness plane cut through the mesh-such as that shown in Figure 3-15. The plane cut shown in Figure 3-15 is located in the center of the elliptical cylinder and is aligned with the y-z coordinate plane.

Figure 3-15: Plane cut—Cut Type: Display cut option, y-z plane

You can align the cutting plane with any of the three Cartesian coordinate planes by means of the Cut Orientation slider bars (see "Specifying the Cut Orientation," below).

Display elements Option

When you select the Display elements option, GAMBIT displays a region of the mesh defined with respect to the cutting plane. You can specify which region of the mesh is displayed by means of Display elements suboptions. The Display elements suboptions are as follows:

Suboption Description
Displays elements that exist below the cutting plane
0 Displays elements that are intersected by the cutting plane
+ Displays elements that exist above the cutting plane

A set of radio buttons corresponding to the Display elements suboptions is located above the Cut Orientation slider bars in the lower section of the Examine Mesh form. To select a Display elements suboption, click its corresponding radio button.

Figure 3-16 and Figure 3-17 show the effect of the 0 and suboptions on the mesh display for the elliptical cylinder shown in Figure 3-14. In both figures, the cutting plane is centered in the cylinder and aligned with the y-z plane.

Figure 3-16: Plane cut—Cut Type: Display elements, y-z plane, Suboption (0)

Figure 3-17: Plane cut—Cut Type: Display elements, y-z plane, Suboption ()

NOTE: When you select the Display elements option, GAMBIT displays only those elements that meet both the domain and element type specifications currently specified in the Display Type field on the Examine Mesh form. For example, if you select the Plane option and specify the display of pyramidal elements only, GAMBIT displays only those mesh elements that are pyramidal in shape and are intersected by the specified cutting plane. (See "Specifying the Element Type," below.)

Specifying the Cut Orientation

To specify the Cut Orientation, you must specify the alignment and position of the cutting plane. The alignment and position specifications determine the following characteristics of the cutting plane:

The alignment and position of the cutting plane are specified by means of the Cut Orientation slider bars located in the lower section of the Examine Mesh form (see above). There are three Cut Orientation slider bars, labeled X, Y, and Z.

GAMBIT allows you to align the cutting plane such that it is parallel to any one of the three coordinate planes of the active coordinate system. To orient the cutting plane, click the slider box corresponding to the axis that is normal to the desired coordinate plane. For example, to orient the reference plane such that it is parallel to the x- coordinate plane (Figure 3-18), click the slider box labeled Z.

Figure 3-18: Plane cut—Cut Type: Display elements, x-y plane

To reposition the cutting plane in the model domain, left-drag the slider box to the left or right. When you left-drag the slider box, GAMBIT automatically updates the graphics window mesh display to reflect the current position of the box. To change the position of the cutting plane in increments, left-click the slider bar on either side of the slider box.

NOTE: If you activate a coordinate system other than the currently active system, GAMBIT automatically updates the orientation of the cutting plane with reference to the newly active system.

Sphere Option

When you select the Sphere option, GAMBIT displays a spherical cut through the mesh. To customize the spherical cut, you must specify two parameters:

The Cut Type specification determines whether GAMBIT displays a zero-thickness spherical shell or an array of mesh elements defined by their position with respect to the shell. The Cut Orientation specification allows you to position the center of the sphere and to specify the radius of the sphere.

Specifying the Cut Type

To specify the Cut Type, you must select one of the following options:

The spherical-cut Display cut and Display elements options produce effects similar to those of the corresponding plane-cut options but differ as outlined below.

Display cut Option

When you select the spherical-cut Display cut option, GAMBIT displays a zero-thickness spherical shell such as that shown in Figure 3-19.

Figure 3-19: Sphere cut—Cut Type: Display cut option

The lines shown on the surface of the spherical cut represent lines of intersection between the sphere and either the mesh-element faces or the geometrical boundaries of the model components. You can position the sphere within the model domain and specify its radius by means of the Cut Orientation slider bars (see "Specifying the Cut Orientation," below).

Display elements Option

When you select the Display elements option, GAMBIT displays a region of the mesh defined relative to the cutting sphere. You can specify which region of the mesh is displayed by means of Display elements suboptions. The Display elements suboptions are as follows:

Suboption Description
Displays elements that exist entirely outside the cutting sphere
0 Displays elements that are intersected by the cutting sphere
+ Displays elements that exist entirely inside the cutting sphere

A set of radio buttons corresponding to the Display Elements suboptions is located above the Cut Orientation slider bars in the lower section of the Examine Mesh form. To select a Display elements suboption, click its corresponding radio button.

Figure 3-20, Figure 3-21, and Figure 3-22 show the effect of the , 0, and + suboptions, respectively, on the mesh display for the elliptical cylinder shown in Figure 3-14. In each figure, the cutting sphere is located in the center of the cylinder, and its radius is that shown in Figure 3-19, above.

Figure 3-20: Sphere cut—Cut Type: Display elements, Suboption ()

Figure 3-21: Sphere cut—Cut Type: Display elements, Suboption (0)

Figure 3-22: Sphere cut—Cut Type: Display elements, Suboption (+)

NOTE: When you select the Display elements option, GAMBIT displays only those elements that meet both the domain and element type specifications currently specified in the Display Type field on the Examine Mesh form. For example, if you select the Sphere option and specify the display of pyramidal elements only, GAMBIT displays only those mesh elements that are pyramidal in shape and are intersected by the specified cutting sphere. (See "Specifying the Element Type," below.)

Specifying the Cut Orientation

To specify the Cut Orientation, you must specify the position and radius of the cutting sphere. The position and radius of the cutting sphere are specified by means of the Cut Orientation slider bars located in the lower section of the Examine Mesh form (see above).

When you specify a Sphere cut, GAMBIT displays four Cut Orientation slider bars, labeled X, Y, Z, and R. The X, Y, and Z slider bars allow you to specify the position of the center of the sphere relative to the axes of the active coordinate system. The R slider bar allows you to specify the radius of the sphere.

Range Option

When you select the Range option, GAMBIT displays only those mesh elements the quality of which falls within a specified range with respect to a specified Quality Type criterion (see Figure 3-23).

Figure 3-23: Elliptical cylinder mesh—Range option

To display mesh elements by means of the Range option, you must specify the following parameters:

To specify the quality criterion, you must use the Quality Type option button located at the bottom of the Display Type field (see "Specifying the Quality Type," below). To define the range, you must specify its lower and upper limits by means of the range components located in the lower section of the Examine Mesh form (see below).

When you select the Range option, GAMBIT displays three components on the lower part of the Examine Mesh form:

Histogram

The range histogram consists of a bar chart representing the statistical distribution of mesh elements with respect to the specified quality criterion. Each vertical bar on the histogram corresponds to a unique set of lower and upper quality limits. To display those elements the quality of which falls within the limits represented by any vertical bar on the histogram, left-click the corresponding bar.

Show worst element Check Box

When you select the Show worst element check box, GAMBIT displays only the single worst element in the mesh based on the currently selected Quality Type criterion.

Lower and Upper Limit Slider Bars

The Lower and Upper limit slider bars allow you to specify the lower and upper limits of the quality range that determines which elements are displayed in the graphics window. To specify the Lower or Upper limit of the range, left-drag the appropriate slider box to the desired location. To change the Lower or Upper limit of the range incrementally, left-click the appropriate slider bar on either side of the corresponding slider box.

NOTE: If the Lower value is greater than the Upper value, GAMBIT simultaneously displays those elements with quality values less than the Upper value and greater than the Lower value.

Specifying the Element Type

When you select the Display elements option, GAMBIT displays two-dimensional (face) and/or three-dimensional (volume) elements in the graphics window. GAMBIT allows you to customize the mesh display so that only specified types of elements are displayed. To specify the element type, you must specify two parameters:

The class specification determines whether GAMBIT displays face elements or volume elements. The shape specification determines which element shapes are included in the set of displayed elements.

Class

For the purposes of displaying the mesh, there are two classes of elements:

Each class is associated with its own set of available element shapes (see below). To specify a class, left-click the class option button in the Display Type field and select either the 2D Element or 3D Element option.

Shape

When you select an element class, GAMBIT displays a set of option selector buttons that represent the element shapes available for the specified class. The option selector buttons are located at the right side of the class option button.

The following table shows the element shapes corresponding to each element class.

Element Class Shape Selector Button
2D Element Quadrilateral
  Triangle
3D Element Hexahedron
  Tetrahedron
  Prism
  Wedge

When you display mesh elements by means of the Examine Mesh form, GAMBIT displays only those elements the shapes of which match the current element-type specifications. For example, if you specify a plane cut according to the following parameters:

Parameter Specification
Class 3D Element
Shape Hexahedron, Wedge

GAMBIT displays only those volume elements that meet both of the following criteria:

Similarly, if you specify a plane cut according to the following parameters:

Parameter Specification
Category 2D Element
Shape Quad

GAMBIT displays only those face elements that are intersected by the specified plane and possess a quadrilateral shape (see Figure 3-24).

Figure 3-24: Plane cut, y-zplane—2D Element, Quad

Specifying the Quality Type

The quality-type specification defines the criterion that determines the following mesh display characteristics:

The following sections describe the quality types available in GAMBIT and the correspondence between quality types and the mesh element types described in the previous section.

Quality Type Definitions

GAMBIT provides the following mesh quality-type specifications:

The following sections summarize the definitions and characteristics of each of the specifications listed above.

Area

The Area specification applies only to 2-D elements and represents mesh quality on the basis of element area.

Aspect Ratio

The Aspect Ratio applies to triangular, tetrahedral, quadrilateral, and hexahedral elements and is defined differently for each element type. The definitions are as follows.

Triangular and Tetrahedral Elements

For triangular and tetrahedral elements, the Aspect Ratio () is defined as:

where f is a scaling factor, and r and R represent the radii of the circles (for triangular elements) or spheres (for tetrahedral elements) that inscribe and circumscribe, respectively, the mesh element. For triangular elements, f=1/2; for tetrahedral elements, f=1/3.

By definition, , where describes an equilateral element.

Quadrilateral and Hexahedral Elements

For quadrilateral and hexahedral elements, is defined as:

where ei is the average length of the edges in a coordinate direction (i) local to the element (see Figure 3-25) and n is the total number of coordinate directions associated with the element. For quadrilateral elements, n = 2; for hexahedral elements, n = 3.

Figure 3-25: Aspect Ratio ()—quadrilateral element

By definition, , where describes an equilateral element.

Diagonal Ratio

The Diagonal Ratio () applies only to quadrilateral and hexahedral elements and is defined as follows:

where the di are the lengths of the element diagonals. For quadrilateral elements, n = 2; for hexahedral elements, n = 4.

By definition, . The higher the value of , the less regularly shaped is its associated element. For square quadrilateral elements and cubic hexahedral elements, .

Edge Ratio

The Edge Ratio () is defined as follows:

where si represents the length of the element edge i, and n is the total number of edges associated with the element.

By definition, . The higher the value of , the less regularly shaped is its associated element. For equilateral element shapes, .

EquiAngle Skew

The EquiAngle Skew () is a normalized measure of skewness that is defined as follows:

where and are the maximum and minimum angles (in degrees) between the edges of the element, and is the characteristic angle corresponding to an equilateral cell of similar form. For triangular and tetrahedral elements, = 60. For quadrilateral and hexahedral elements, = 90.

By definition, , where = 0 describes an equilateral element, and = 1 describes a completely degenerate (poorly shaped) element.

NOTE: For pyramidal mesh elements, is equal to its maximum value for any of the five faces of the mesh element. In an ideal pyramidal mesh element, all four triangular faces are equilateral and the base of the pyramid is a square.

Table 3-1 outlines the overall relationship between and element quality.

Table 3-1: vs. Mesh Quality

Quality
= 0 Equilateral (Perfect)
0 < ≤ 0.25 Excellent
0.25 < ≤ 0.5 Good
0.5 < ≤ 0.75 Fair
0.75 < ≤ 0.9 Poor
0.9 < ≤ 1 Very poor (sliver)
= 1 Degenerate

In general, high-quality meshes contain elements that possess average values of 0.1 (2-D) and 0.4 (3-D).

EquiSize Skew

The EquiSize Skew () is a measure of skewness that is defined as follows:

where S is the area (2-D) or volume (3-D) of the mesh element, and is the maximum area (2-D) or volume (3-D) of an equilateral cell the circumscribing radius of which is identical to that of the mesh element.

By definition, , where = 0 describes an equilateral element, and = 1 describes a completely degenerate (poorly shaped) element.

The relationship between and mesh quality shown in Table 3-1, above, applies to values of , as well. In general, high-quality meshes contain elements that possess average values of 0.1 (2-D) and 0.4 (3-D).

NOTE: The EquiSize Skew quality metric applies to any mesh element that includes a triangular face. For triangular and tetrahedral elements, all faces of which are strictly triangular, the EquiSize Skew metric applies directly. For wedge or pyramidal elements, which include combinations of triangular and quadrilat­eral faces, GAMBIT computes both EquiSize Skew metrics (for the triangular faces) and EquiAngle Skew metrics (for the quadrilateral faces and 3-D element, itself) and reports the maximum computed metric as the element skewness. As a result, EquiSize Skew metrics reported for meshes that contain wedge and/or pyramidal elements may include skewness values attributable to EquiAngle Skew computations.

MidAngle Skew

The MidAngle Skew () applies only to quadrilateral and hexahedral elements and is defined by the cosine of the minimum angle () formed between the bisectors of the element edges (quadrilateral) or faces (hexahedral) (see Figure 3-26).

Figure 3-26: MidAngle Skew () definition—quadrilateral element

For quadrilateral elements,

For hexahedral elements,

where 1, 2, and 3 are the three angles computed from the face-bisecting lines of the element.

By definition, , where = 0 describes an equilateral element, and = 1 describes a completely degenerate (poorly shaped) element.

Size Change

The Size Change () specification represents the maximum ratio of the area (for 2-D elements) or volume (for 3-D elements) of an element rela­tive to its neighboring elements. To calculate the Size Change value for any ele­ment i, GAMBIT first computes the individual ratios of its area or volume relative to each of its neighboring elements. Each ratio can be expressed as

where is the area or volume of element i, and is the area or volume of neighboring element j. The Size Change () specification is

where n is the total number of elements adjacent to element i.

By definition, , and represents an element that is surrounded by elements the areas or volumes of which are exactly equal to its own.

Squish

The Squish quality metric () is used to quantify the non-orthogonality of a 3-D element with respect to its faces. To cal­culate the overall Squish value for any ele­ment i, GAMBIT first computes squish values with respect to each of its faces (j). Each individual squish value () can be expressed as:

where is the normal vector for face j and is the vector from the centroid of the element to the centroid of face j. The Squish () specification is

where n is the total number of faces on element i.

By definition, , and represents an element the faces of which demonstrate complete orthogonality.

Stretch

The Stretch quality metric () applies only to quadrilateral and hexahedral elements and is defined as follows:

where di is the length of diagonal i, sj is the length of the element edge j, and n and m are the total numbers of diagonals and edges, respectively. For quadrilateral elements, n = 2, m = 4, and K = 2; for hexahedral elements, n = 4, m = 12, and K = 3.

By definition, , where = 0 describes an equilateral element, and = 1 describes a completely degenerate (poorly shaped) element.

Taper

The Taper quality metric () applies only to quadrilateral and hexahedral mesh elements and is defined as follows.

For any quadrilateral (or hexahedral) mesh element, it is possible to construct a parallelogram (or parallelepiped) such that the distance between any given corner of the parallelogram (or parallelepiped) and its nearest element corner node is a constant value. As a result, any vector, T, constructed from an element corner node to the nearest corner of the parallelogram (or parallelepiped) possesses a magnitude identical to that of all other such vectors (see Figure 3-27).

Figure 3-27: Taper quality metric definition—quadrilateral element

Each vector, T, can be resolved into components, Ti, that are parallel to the bisectors of the mesh element. For quadrilateral elements, there are two such components for each vector; for hexahedral elements, there are three. The Taper quality metric () is defined as the normalized maximum of all such components for the element.

By definition, , where = 0 describes an equilateral element, and = 1 describes a completely degenerate (poorly shaped) element.

Volume

The Volume specification applies only to 3-D elements and represents mesh quality in terms of mesh element volumes.

Warpage

The Warpage () applies only to quadrilateral elements and is defined as follows:

where Z is the deviation from a best-fit plane that contains the element, and a and b are the lengths of the line segments that bisect the edges of the element.

By definition, , where = 0 describes an equilateral element, and = 1 describes a completely degenerate (poorly shaped) element.

Element Types vs. Quality Types

Each element type is associated with a unique set of available quality types. Table 3-2 summarizes the correspondence between mesh element types and the quality types described above. (Shaded boxes in the table represent quality types that are available for each corresponding element type.)

Table 3-2: Mesh element type vs. quality type

Quality Type
2-D Element 3-D Element
Area
X
X
       
Aspect Ratio
X
X
X
X
X
X
Diagonal Ratio
X
 
X
     
Edge Ratio
X
X
X
X
X
X
EquiAngle Skew
X
X
X
X
X
X
EquiSize Skew
X
X
X
X
X
X
MidAngle Skew
X
 
X
     
Size Change
X
X
X
X
X
X
Squish
   
X
X
X
X
Stretch
X
 
X
     
Taper
X
 
X
     
Volume
   
X
X
X
X
Warpage
X
         

To specify a quality type, click the Quality Type option button and select the quality type from the option menu.

NOTE: The Quality Type option menu includes only those quality types that are common to all currently selected element types. For example, if you specify the element type to include only 2D Element rectangles, the Quality Type option menu includes all quality types except Volume. If you specify the element type to include both of the 2D Element shapes (rectangles and triangles), the Quality Type option menu includes only the following options: Area, Aspect Ratio, Edge Ratio, EquiAngle Skew, and EquiSize Skew.

Specifying the Display Mode

Display Mode specifications determine the appearance of the mesh display. To specify the display mode, you must specify the following parameters:

The quadrant specification determines which graphics window quadrants are affected by the current specifications on the Examine Mesh form. The appearance specification determines the manner in which the mesh elements are displayed in each enabled quadrant.

Specifying the Enabled Quadrants

The quadrant specification field consists of a set of five command buttons that are identical to the quadrant command buttons used to enable and disable general graphics operations in each of the quadrants. For a description of the use of quadrant command buttons, see Section 3.4.1, above.

Specifying the Appearance

GAMBIT provides the following options with respect to the appearance of the displayed mesh:

The Wire option specifies that GAMBIT displays a wireframe view of the mesh. The Faceted option specifies that GAMBIT renders the mesh display in either a colored, shaded, or hidden view. Neither option is exclusive of the other.

Wire Option

When you select the Wire option, GAMBIT displays all lines corresponding to the edges of all displayed mesh elements.

Faceted Option

When you select the Faceted option, GAMBIT renders all displayed mesh elements to illustrate their shape, location, and/or quality characteristics. There are three Faceted rendering suboptions, each of which is mutually exclusive of the others:

Quality Suboption

When you select the Quality suboption, GAMBIT renders the faces of all displayed mesh elements as follows:

If you rotate the model by means of the mouse, the colors of the element faces change to reflect changes in the position of each element face with respect to the light source. (For a description of the procedures and specifications required to modify the position and brightness of the light source, see "Modify Lights," above.)

Shade Suboption

When you select the Shade suboption, GAMBIT renders the faces of all displayed mesh elements in shades of gray to reflect the position of each face with respect to the light source.

Hidden Suboption

When you select the Hidden suboption, GAMBIT displays a wireframe view of the mesh but hides all lines that are concealed behind displayed mesh element faces.

Using the Examine Mesh Form

The Examine Mesh form allows you to specify the type of mesh elements displayed and the display mode for those elements. It includes the following specifications.

Display Type:
Plane displays a plane cut through the mesh. The cut can represent either a zero-thickness plane or mesh elements defined in relation to those intersected by the plane (see "Plane Option," above).
Sphere displays a spherical cut through the mesh. The cut can represent either a zero-thickness spherical shell or mesh elements defined in relation to those intersected by the shell (see "Sphere Option," above).
Range displays all mesh volume elements possessing quality values within a specified range for one of several available mesh quality criteria (see "Range Option," above).
3D Element
2D Element
specifies the class of elements to be displayed. Element classes include face elements (2D Element) and volume elements (3D Element).

specifies 2D Element shapes.

Specifies 3D Element shapes.

Quality Type:
Area
Aspect Ratio
Diagonal Ratio
Edge Ratio
EquiAngle Skew
EquiSize Skew
MidAngle Skew
Size Change
Squish
Stretch
Taper
Volume
Warpage
allows you to specify the quality criterion that determines which elements are displayed by means of the Range option and the coloration of elements for faceted mesh displays. (See "Specifying the Quality Type," above.)
Display Mode:
(quadrant command buttons) enable or disable any or all quadrants with respect to changes in mesh display. Changes made by means of the Examine Mesh form are applied only to enabled quadrants.
Wire specifies a wireframe view of the displayed mesh elements.
Faceted specifies a faceted rendering of all displayed mesh element faces.
Faceting Type:
Quality colors each mesh element face to represent its quality and shades each mesh element face to reflect its current position with respect to the light source. (NOTE: Element colors change slightly when you reorient the model.)
Shade shades the mesh elements to create a three-dimensional rendering of the mesh.
Hidden displays a wireframe view of the model but hides all lines that are concealed behind other elements in the current mesh specification and orientation.
Cut Type:
Display Cut displays a zero-thickness planar or spherical cut through the mesh.
Display Elements displays elements defined in relation to the plane or spherical shell.
Cut Orientation: contains slider bars that allow you to specify the orientation of a plane cut or the radius and location of the center of a spherical cut. The Cut Orientation field also includes radio buttons that allow you to specify the region of elements to be displayed by means of the Display elements option. (NOTE: If you select the Display Type:Range option, GAMBIT displays a histogram and slider bars that allow you to specify the upper and lower limits for the element display range. For a description of the range-limit slider bars, see "Range Option," above .)

Plane Cut Slider Bars

The plane-cut slider bars (see below) allow you to change the position of the cut plane in the x (X), y (Y), and z (Z) directions.

To change the location of the cut plane, left-click one of the slider boxes and drag it to a new location on its slider bar. GAMBIT repositions the plane according to the final position of the slider box.

The plane-cut sliders also allow you to change the orientation of the cut plane with respect to the coordinate planes. The X, Y, and Z sliders orient the cut plane perpendicular to the x, y or z coordinate planes, respectively, of the active coordinate system. To change the orientation of the cut plane, left-click the appropriate slider.

Spherical Cut Slider Bars

The spherical-cut slider bars allow you to change the location of the center of the cutting sphere in the x (X), y (Y), and z (Z) directions and to specify the radius (R) of the sphere.

To change the location of the sphere center, left-click one of the X, Y, or Z slider boxes and drag it to a new location on the slider bar. To change the sphere radius, left-click the R slider box and drag it to its new location.

Display elements Suboption Radio Buttons

When you select the Display Elements option (see above), GAMBIT displays three radio buttons above the Cut Orientation slider bars. The radio buttons allow you to specify the region of mesh elements to be displayed.

The options specified by means of the radio buttons are as follows.

Option Plane Cut Spherical Cut
Negative coordinate direction Outside
0 Intersection Intersection
+ Positive coordinate direction Inside

For both the plane-cut and spherical-cut options, the 0 option specifies that only those elements intersected by the specified plane or spherical shell are displayed.

For plane cuts, the and + options display all elements located in the negative and positive coordinate directions, respectively, relative to the elements intersected by the plane.

For spherical cuts, the and + options specify the display of elements inside and outside, respectively, those elements intersected by the spherical shell.

Update updates the mesh display to reflect the current specifications.


next previous contents index © 1998-2007 Fluent, Inc. All rights reserved.