NAME	ucd minmax

SYNOPSIS: UCD filter to override data min/max range and mesh_id

Author: Ian Curington, AVS Inc, Staines, UK  < ianc@avs.com >

Type	Filter

Input	UCD

Output	UCD

Parameters:
	Name		Type		Defaults, Range

	min		float		0.0, unbounded
	max		float		1.0, unbounded
        Freeze Mesh     boolean         on/(off)

Source: ucd_minmax.c


DESCRIPTION:
  
   For Transient UCD data, where data ranges are changing,
   and/or the mesh is static,
   this module copies UCD input to UCD output, with
   almost everything unchanged, except for the data
   minimum and maximum header values, and the mesh_id.
   This is picked up by ucd_contour or ucd_legend,
   to colour the data, using user-specified values for
   min and max, as set on the parameter dials.
   This is important for animation,
   as the colour range must remain constant over time
   varying data. This module will work with either
   Node or Cell based data. Make sure the range is outside
   the actual data values.
  
NOTES:

This module is intended as a source example for other UCD module
developers.

Special Feature: The "Freeze Mesh" button makes the assumption
   that the mesh topology and positions have not changed since
   the last UCD. This allows modules like ucd_to_geom to cache
   information and run up to 10 times faster.
   This will be most useful for Transient UCD data where each
   time step is stored in a separate file, accessed with 
   read_ucd.

Restrictions: This relies on AVS version 4.0 or later,
              as READ UCD had cell data bugs in version 3.0.
              Also, several function calls will be missing on
              version 3.0.

Problem areas:
   Make sure the range is OUTSIDE the actual data values, or
   ucd_contour or ucd_legend may die, or create black artifacts
   in the image.
   This module copies ALL the ucd data across, doubling storage.

Example Network: ( see ucd_minmax.net )

    Generate Colormap    READ_UCD 
               |           |
               |         UCD_MinMax
               |   |-------|
           UCD Legend      |
               |           |
               ----        |
                  |        |
                 UCD TO GEOM 
                      |
                      |
              RENDER GEOMETRY
                     |
              DISPLAY PIXMAP

  
  
