Some keys are active and serve as shortcuts for commands in the pop-up menu.

Press this button and move the mouse to rotate interactively the plot. The window can be seen as a virtual trackball, when the User holds down this button and moves the mouse from left to right and viceversa, the plot rotates along the windows vertical axis. When the User holds down this button and moves the mouse from top to bottom and viceversa, the plot rotates along the windows horizontal axis. If the Shift key is pressed when the User moves from top to bottom, holding down the left button, the rotation is performed in the windows Z axis.

This is a multifunction button. By default, it is used to change the Scale of the plot, by holding it pressed and moving the mouse to the top (to increase the scale) or to the bottom (to decrease the scale). However, it is possible to change its function using the command middle mouse button in the pop-up menu, see below.

When the User press the right mouse button, a pop-up menu appears on the window:

• set symbol

  

  The values in 3D-plots can be represented by:

  point	a very tiny point.
  cross	a three-dimensional cross (default).
  cube	a three-dimensional cube.
  sphere	a three-dimensional sphere.
  number	for variables: the sequential index of the variables for objects: the number as defined in the data file.
  name	for variables: the sequential index of the variables. for objects: the name as defined in the data file.
  size	it is used to select the symbol size. Any real number between 0.0 and 4.0 can be used. Size modifications are only allowed for crosses, cubes and spheres.

• symbol color

  

  The options are:

  type	In object plots, correspond with the type objects defined with File->Object type->Modify. If this is not an object plot or no different objects types have been defined, this option colors all the objects in white.
  depth	The points are given colors from red to blue depending of how far are from the observer. This coloring scheme helps to appreciate the three-dimensionality of the plot.
  spectrum	In object plots, the points are colored according to the spectrum variable defined using File->Object type->Define spectrum.... If no spectrum has been defined, this option does not even appear in the pop-up menu.

• find object

  

  This command allows to locate and highlight an object of the plot. The search can be made by name or by number. When by name is selected the User must specify the name in the command line. The name can also be approximate, letting VolSurf decide which is the closest name to the one specified.

• views

  

  The options are:

  save view	the current point of view is stored on disk.
  load view	the last saved point of view is restored
  stereo left	rotates the picture -3 degrees (clockwise) on the vertical axis of the window.
  stereo right	rotates the picture +3 degrees (clockwise) on the vertical axis of the window.

  The file that stores the points of view is common for all the windows opened by VolSurf. Therefore, it is possible to force different windows to present the same point of view by saving the view in one of them and loading the view in the rest. This operation is very useful when it is necessary to compare different 3D plots, and the User wants to see all of them from the same point of view.

  The stereo right and left options allows the User to generate right and left eye views of the picture, in order to produce stereoviews of the plot. The procedure is as follows:

  1. Save the current view with the views->save view command.

  2. Use the views->stereo left command to generate the left eye view of the plot. Save this view in an RGB (only for IRIX), PostScript or HPGL file using the output commands

  3. Reload the previously stored view with theviews->load view command.

  4. Use the views->stereo right command to generate the right eye view of the plot. Save this view in an RGB (only for IRIX), PostScript or HPGL file using the output commands

  5. Merge both views in a single file, side by side, using a suitable autoedition program. For example, it is possible to merge two RGB files using showcase. PostScript and HPGL files can be imported, merged and edited in external autoedition programs.

  Note: stereoviews suitable for publication should present two identical side-by-side views, rotated about 6 degrees one from the other. Equivalent points in both views should be separated by 6.5 cm, as a maximum.

• middle mouse button

  

  As mentioned above, the middle mouse button is multifunction. Use this command to change its functionality. The options are:

  scale (M)	This is the default. Use this option to change the scale of the plot by pressing the middle mouse button and moving the cursor up and down.
  translate (M)	Use this option to translate the plot in the XY window plane.
  perspective near plane	Use this option to move along the window Z axis the clipping plane that defines the side nearest to the observer of 3D scenario.
  perspective far plane	Use this option to move along the window Z axis the clipping plane that defines the side farthest to the observer of 3D scenario.

  The M key toggles the function of the middle mouse button between scale and translate.

  In highly complex plots, the two last options are very useful to hide below and behind the clipping planes parts of the plot that are disturbing in order to see the most interesting areas

• visualisation style

  

  This menu contains different options to customise the way the plot is represented in the screen.

  line smoothing	The options are ON and OFF. When it is ON, VolSurf uses antialiasing techniques to render smoother lines in the screen. In plots containing a large number of points this option can increase the time required to update the display.
  symbol font	The options are SMALL and LARGE. This option defined the font used by VolSurf to render in the screen the names and numbers of the points.
  fog	The options are ON and OFF. When it is ON, some fog is added to the picture in order to simulate the deepness of the objects.
  grid cage	The options are ON and OFF. When it is ON the plot displays a cube showing the boundaries of the three-dimensional space represented.
  monochrome	The options are ON and OFF. When it is ON, the plot is rendered in black and white.
  background	The options are BLACK and WHITE. Changes the background of the plot. The foreground colors, fog, etc... change accordingly.
  perspective	The options are ON and OFF. When it is ON the plot has a natural perspective, and objects far away from the observer are smaller. When it is OFF the plot exhibit orthographic perspective.

• output

  

  VolSurf can save the contents of 3D-plots in three formats: RGB bitmaps, PostScript files and HPGL plotter files.

  RGB (only for IRIX)	Saves the contents of the window in IRIS RGB format.
  PostScript color and PostScript B&W	Saves the contents of the window in PostScript format, in color or in black and white. In either case, the plot will be given white background.
  HPGL hard and HPGL soft	Saves the contents of the window in HP plotter format. This is a convenient format to export, as a vectorial drawing, into a autoedition program. If it will be used to be exported into a external application, please use the HPGL soft. On the other hand, if it will be used to produce output in an real plotter, please use the HPGL hard. In either case, the plot will be given white background.

  HPGL format is the most convenient way to export the plot into external autoedition programs. Using those programs the size of the plot can be adjusted, it is possible to add labels, etc... As stated above, the HPGL files produced by VolSurf can be optimized for their use in autoedition (HPGL soft) or for producing output in real hardware plotters. In the first case, the lines are ordered using the distance to the observer, and therefore the lines nearer to the observer will overlap the ones farther from him. This will result in a more realistic picture. However, when the plots are complex and a plotter is used to produce the output, this option will require to change the pen for every line and therefore, the time required for producing the plot will be extremely large. In this case it is better to use the HPGL hard, option, since in this case the lines are ordered by colors and it minimizes the number of pen changes.

  In all those options, the User is prompted to enter the file name in a small box at the bottom of the window.

• exit (X)

  Closes the window and exits from the plot3D application