NAME
        LatValue

   DESCRIPTION
        This module creates a sphere to mark the location of a grid point in any
        1..4-D latttice.  The I, J, K, and T coordinates of the grid point as well
        as its data value are printed in the corresponding widgets.  The sphere
        that is generated can be scaled and colored.  If the input lattice is 4-D
        then the coordinates for the sphere will come from the first three
        dimensions.

   INPUTS

      Input -- Lattice
         (1..4-D).
         This is the input lattice from which to get the grid point.

      Colormap -- Lattice (Opt.)
         (1-D, 4-vector, float).
         This is an optional lattice which can be used to color the sphere based
         on the data value at the specified grid point.

   WIDGETS

      I -- Slider
         This is the I component of the grid location.

      J -- Slider
         This is the J component of the grid location.

      K -- Slider
         This is the K component of the grid location.

      T -- Slider
         This is the T component of the grid location.

      Channel -- Slider
         This is the channel (data variable) at the specified grid location.  If there
         is only one then this slider will be hidden.

      Data Value -- Text
         This is the data value at the grid location.

      I Coordinate Value -- Text
         This is the I coordinate value at the grid location.

      J Coordinate Value -- Text
         This is the J coordinate value at the grid location.

      K Coordinate Value -- Text
         This is the K coordinate value at the grid location.

      T Coordinate Value -- Text
         This is the T coordinate value at the grid location.

      Radius Style -- Option Menu
         This determines how the sphere's radius will be calculated.  If "Fixed"
         is chosen then the radius will be predetermined for all the grid locations
         based on the coordinates.  If "Data-dependent" is chosen then the
         sphere's radius will be based on the absolute value of the data at the
         specified grid location.

      Color Source -- Option Menu
         This determines how the sphere will be colored.  If "Sliders" is chosen
         then the color will come from the settings of the "Red", "Green", "Blue",
         and "Opacity" sliders.  If "Colormap" is chosen then the color will come
         from the connected colormap.  If no colormap is connected and
         "Colormap" is chosen then it will use the settings of the color sliders.

      Red -- Slider
         This is the red component of the sphere's color.

      Green -- Slider
         This is the green component of the sphere's color.

      Blue -- Slider
         This is the blue component of the sphere's color.

      Opacity -- Slider
         This is the opacity component of the sphere's color.

      Scale -- Dial
         This is the scaling factor to be applied to the sphere's radius.

      Complexity -- Dial
         This is the complexity of the sphere.  The complexity determines how
         many polygons are used to approximate its surface.  The range is from
         0.0 to 1.0.  A value of .5 generates approximately 200 polygons.

      Drawing Style -- Option Menu
         This is the style used to draw the sphere:
         
            Filled - The sphere is drawn as a solid (default setting).
            Wireframe - The sphere is drawn with only lines.
            Points - The sphere is drawn with only points.
            Invisible - The sphere is hidden.

      Lighting Model -- Option Menu
         This is the method used to light the sphere.  The default is usually
         Phong lighting (specifiable in one's "~/.Renderrc" file), but flat lighting
         can also be set to make all of the sphere exactly the same color (i.e. no
         3-D appearance).

      Number Format -- Text
         This is the format specification for the data and coordinate values.  It is
         the same specification format used by the C language's "printf".  This
         specification is always used except for the data value when it's of
         integer type.  The coordinates will always be of floating-point type.

   OUTPUTS

      Marker -- Geometry
         This is the geometry of the sphere.

   KNOWN PROBLEMS
      There are no known bugs.

   SEE ALSO
      Ball, Particles2, Render
      
      -
      
      Hans Vahlenkamp (Hans.Vahlenkamp@noaa.gov)
      Geophysical Fluid Dynamics Laboratory / NOAA
      Princeton University Forrestal Campus
      http://www.gfdl.noaa.gov