User AVS Modules					   city scape


NAME
     city scape - version 2, upgrade from "3D bar chart" in AVS5.
                  3D block diagram, with averaged statistics
                  on side shadow panels, and annotation. A transparent
                  theshold sheet is superimposed on city. Blocks can
                  be picked for interogation of cell number.
                  parts may be turned on or off for clarity.
                  Two scalar fields can be displayed, one contolling
                  height, the other color, with two independent side
                  stacked side bar statistics.

AUTHOR: Ian Curington, Advanced Visual Systems, Esher, UK

SUMMARY
     Name	   city_scape

     Type	   mapper

     Inputs	   field 2D scalar float uniform (primary)
         	   field 2D scalar float uniform (secondary, optional)
		   colormap 
		   struct upstream geom

     Outputs	   geometry
                   X-index ( from mouse pick )
                   Y-index

     Parameters	   Name		   Type		  Default	 Min	   Max
		   Z scale	   float	  1.0		 none	   none
                   width           float          .6             0.        1.
                   offset          float          .1             0.        1.
                   threshold       float          1.             none      none
                   tic scale       float          1.             none      none
                   h-label inc     int
                   v-label inc     int
                   draw_city       boolean
                   draw_sidebars   boolean
                   draw_ticmarks   boolean
                   draw_labels     boolean
                   draw_threshold  boolean


DESCRIPTION
     This is version 2, substantial upgrage from version 1 at the IAC,
     and upgrade from "3D bar chart" in AVS5.
     This module provides 3D block diagram, with averaged statistics
     on side shadow panels, and annotation. A transparent
     theshold sheet is superimposed on city. Blocks can
     be picked for interogation of cell number.
     parts may be turned on or off for clarity.
     Two scalar fields can be displayed, one contolling
     height, the other color, with two independent side
     stacked side bar statistics.


     The city scape module converts a two-dimensional floating point
     field into group of 3D blocks, represented as a GEOM-format mesh.
     Each element of the field is mapped to a "building".
     The height of each block above each point is proportional to the scalar
     value of the field. This is my attempt at "Business Graphics",
     for a multi-dimensional telecommunications statistics data
     application, except in interactive 3D.

     Side panels show the Min, Max and Average along each row and column
     in the 2D data.

     A threshold transparent sheet can be moved through the city to
     highlight specific values, where only values above the threshold
     will stick up beyond the sheet.

     Line tic marks and text labels show the row and column numbers,
     and the vertical scale

     The labels can be less frequent than tics, so they don't bunch up,
     using the increment controls, independent for horizontal and
     vertical.

     The blocks don't have bottoms, so you can look inside!

     This module does no normalization of the Z-height, while the
     x-y plane is approx 0.0 to 1.0 on each side.
     Use the dials to get your data range under control.
     The dials are unbounded to allow any data range.
     but will be over-sensitive for small numbers.
     Try flying over the city in perspective.

INPUTS

     Data Field (required; field 2D scalar uniform float)
     The input data must be a 2D field with a scalar data value at
     each element.

     Colormap 
     Colors each block building in the city a specific color,
     according to the data value at that point.

PARAMETERS

     Z scale    height scale for whole city

     width      relative width of each block, or narrowness of streets

     offset     how far away the average shadow planes are from city

     threshold  height of threshold sheet in city

     tic scale  vertical scale tic mark pitch control

OUTPUTS

     Geometry
	  The output is	an AVS geometry.

EXAMPLE

     see the city_scape.net in this directory.