Menu Bar Functions

  The V2K menu bar provides access to a variety of functions which perform file I/O, set picking masks, viewing preferences or rendering modes and activate other utilities. Many of the menu entries list hot keys which permit rapid activation of the respective facility via the keyboard. Click on any of the listed menu items to learn more of what functionality is available.  

The File Menu

 The File menu performs basic I/O functions and enables formal program termination. Selection of the Open... menu entry displays a specialized file dialog which enables the selection of the file type, associated file format and the precision of the data. A summary of valid file types and acceptable formats is available here.

 The Save As... menu entry also prompts the display of the file dialog for data export. Either an updated mesh or an updated neutral map file may be written based upon user settings within the dialog. However, to write the mesh the desired blocks must first be selected, and similarly, to write an updated (or new) neutral map file, all interfaces must be selected.

The Edit Menu

  The Edit menu shown below provides access to functions concerning, for the most part, visualization objects.

 The Clear Face/Plane entry removes from the display and program memory the selected mesh plane faces which are typically created (temporarily) to permit visualization of the volume mesh. Similarly, the Cut Block facility removes the selected block(s) from the display and program memory. Note that these blocks are non-recoverable.

 The Select pull-over menus permit operation on four distinct classes of objects as shown. For the first three object types, associated pull-over menus permit the selection of Displayed objects of the associated type, NOT Displayed (i.e. hidden) objects or All objectsof the associated type within the database. These are short-cut picking mechanisms as all currently displayed objects could certainly have been selected individually. Note that the NOT Display option provides a means to restore the rendering of objects which are not currently rendered.

 The Select Interfaces facility is functionally identical to those described above, but the selections present in the associated pull-over menu (as shown to the left) are dynamic in that the state of objects within program memory (in terms of their assigned attributes) defines those which are to appear within the menu. In addition, All interface objects currently defined and those belonging to only the Current Block or Selected Block may also be selected using the options in the lower half of the menu.

  Preferences relating to the background color of the graphics display as well as the position of the mesh plane sliders within the main interface window may be set within the panel which is displayed using the Preferences menu item as shown below.

Also included are user settings for the thresholds for the grid quality metrics which include hexahedral volume, stretching and skewness. The results of quality metric calculations invoked from the Solver menu are compared against the thresholds prescribed here, and appropriate warnings will be issued if:

the volume of any hexahedral element is below the Negative Volume threshold,

the stretching between any adjacent elements is greater than Max Stretch Ratio or

the skewness at any element is greater than Max Skewness

The View Menu

 The View menu contains facilities which permit user customization both in terms of "look and feel" as well as operation. The top three items (controllled by the setting of the adjacent check box) toggle the display of the associated interface elements.
 The Center Dot utility toggles the display of a visual reference point about which the zooming will occur; any point positioned at the center dot will remain so positioned for any zooming.

 The Perspective utility toggles the viewing mode between the orthographic and perspective viewing transformations. Though the perspective transformation more closely mimics the behavior of the human eye, there are instances in which the orthographic transformation is useful.

  The Axes menu entry has an associated pull-over menu whose entries toggle the rendering of the body system axes centered about the Origin (rendered in yellow), and the Rotation Axes (rendered in red).

  The Rotation menu entry also has an associated pull-over menu whose entries enable the customization of the manner in which object rotations are to be performed. The first entry is the placement of the Rotation Axes as well as a user preference setting
affecting the manner in which rotations are to be performed.

 The Adjust Center entry will activate a specialized picking mode (signified by the replacement of the default mouse pointer with a white cross-hair) which permits the interactive selection of any displayed grid point (via the right mouse button). Successful selection of a valid point will reposition the rotation axes about this point (via simple translation) and all rotations will henceforth be performed about this new origin. The rotation axes need not be displayed to perform this adjustment. The ability to reposition the rotation center is particularly useful when the visual focus is centered far from the system origin as any object rotations will quickly move the field of interest beyond the view within the display.

 By default, all object rotations are performed incrementally; that is for each mouse event or movement, a single, incremental rotation of the rendered objects will result. The relative magnitude of the mouse movement will be reflected in the extent of the rotation. Activation of the Spin Momentum toggle causes the rotation to persist at a rate commensurate with the mouse movement until a subsequent mouse event alters or cancels the previous event. Note that such a rotation can be suspended by simply clicking the stationary mouse within the display.

  The Snap menu provides a pull-over menu which enables the user to prescribe the rotation increment as either None, which is the continuous mode (the default), 45 degrees and 90 degrees the latter two of which will invoke rotations by this prescribed amount only for rotations about the body fixed axes.

 The Shading pull-over menu permits the user to toggle between Flat and Smooth shading options. This selection, of course, has relevance only when one or more model surfaces are to be rendered as shaded or analysis contours. The Flat shading mode is used to render the associated triangulation as planar facets whereas the Smooth shading mode yields a more aesthetically pleasing representation as individual surface facets are smoothly blended to produce a more "realistic" view of the model.

 The final menu entry reinitializes the current viewing transformation within the display. This is useful when the rendered objects are inadvertantly "lost" beyond the confines of the clipping planes during graphical transformation.

The Style Menu

nbsp;The Style menu provides the controls which permit customization of the manner in which visualization objects are rendered. Note, however, that the selection made here will apply only to those surfaces which have been selected and thus currently active. The Shaded option will employ the shading model as selected from the View menu. The Analysis option is similar to the Shaded option though the shading is based on the variation of a particular scalar quantity defined on the surface rather than its orientation to the light source. This quantity is selected from a series of options provided within the Scalar pull-down menu described below.

The Scalar Menu

 The Scalar menu provides a list of options which govern the manner in which the active surfaces are to be shaded if the analysis mode has been activated within the Style menu described above. The rendering of the surfaces in this manner enables a rapid assessment of the variation of the selected quantity over the surface. The last option, user function, permits the user to render surfaces based upon a scalar function whose defintion has been hand-coded by the user. This function is not yet implemented. Note that the active scalar function is identified by the appearance of an active check box.

The Solver Menu

 The Solver menu contains entries which activate the mesh modification facilities as well as the mesh quality tools. The Interpolate entry activates a transfinite interpolation procedure which is applied to the region of the domain as defined by the settings of the bounding sliders.

 The Smooth options functions in a similar manner though the process employed involves the solution to a Poisson's equation based on the Sorenson and Thomas and MiddleCoef control functions which enforce orthogonality throighout the domain. Note that this facility will function only when the region selected comprises a surface.

 The Redimension option enables one or more grid blocks to be redimensioned according to user requirements. Similarly, the Redistribute option allows the mesh within one or more grid blocks to be redistributed according to usr prescribed spacing data. These facilities are similar in that they invoke a novel three-dimensional volumetric NURBS algorithm which "fits" the volume mesh thereby allowing the character of the initial mesh to be retained during either operation.

  The final entry, Quality, invokes a quality metric calculation panel which provides the controls necessary to evaluate any of three quality metrics across the domain.