From: avs@ncsc.org (AVS account)
Newsgroups: comp.graphics.avs
Subject: Re: What is AVS ?
Date: 10 Apr 92 19:42:02 GMT
Reply-To: davidb@ncsc.org
Organization: North Carolina Supercomputing Center

this is off the top of my head....


-terry

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AVS Overview

Visualization is a method of computing that has emerged from the 
combination of the latest advances in visualization software, 
graphics, networking, high performance systems, and industry 
standards.  Advanced Visual System's Application Visualization 
System (AVS) incorporates all of these technologies into a single 
comprehensive visualization environment.  Visualization allows the 
interaction between the computer system and the user to occur 
through the most efficient form of information exchange - visual 
exchange.  Sight is the primary, and most efficient method for 
receiving, processing, analyzing and assimilating information.  
Visualization is changing the way scientists and engineers perform 
their work.

The Application Visualization System (AVS)

The Complete Visualization Environment

AVS is the industry standard visualization application software and 
development environment.  It is a fully functional visualization 
environment providing more techniques for visualizing information 
than any other system commercially available today.  Available on 
the industry's major computing platforms, AVS is extensible, easily 
tailored, and applicable to a wide range of applications.   

AVS accepts the data produced by instruments, or by scientific and 
engineering simulation software. It provides you with the most 
comprehensive set of data types of any visualization system.  It 
creates a visual display of your data in a variety of forms using a 
wide array of visualization techniques.  AVS has a modular 
architecture comprised of many separate, yet tightly integrated, 
sub-systems that each provide important capabilities.

The Building Blocks of AVS

Modules are the building blocks of AVS.  A module is an independent 
computing element (C or FORTRAN) which is represented by a 
rectangular icon on the screen.  Each module performs a specific 
visualization function or set of functions.  You have access to more 
than 110 modules provided with standard AVS.  Alternatively, you 
can build your own modules to extend or customize AVS.  External 
programs or subroutines written in C or FORTRAN can be easily 
converted into AVS modules.  Public domain modules are available 
via email or ftp.  Contact David Bennett via email at avs@ncsc.org or 
send mail to the International AVS Center, 3021 Cornwallis Road, 
RTP, NC 27709 for more information.

A wide range of data input, filter, mapper and data output modules 
are also included in AVS.  Filters transform data into data, e.g. 
contrast stretch or edge detect.  Mappers transform data into 
geometry, e.g isosurface or arbitrary slice.  And data output modules 
write data to files, send data to peripheral devices, or render data, 
e.g displaying geometry, images and volumes on the screen. 

Visual Program Development

The combination of the Network Editor, AVS modules, and the easy-
to-use graphical user interface provides you with the premier visual 
programming environment.  The Network Editor is a powerful, easy-
to-use tool for quickly developing complex visualization processing 
networks, or application programs.  Simply by connecting together 
modules through mouse-driven point-and-click operations, a "non-
programmer" is capable of creating complex graphical applications 
without writing a single line of code.

The networks created in AVS are interactively reconfigurable and 
re-usable by you.  They may be saved and stored for future use and 
modification.  Modules can be dynamically added, connected and 
deleted from new or existing networks.

The AVS network editor supports rapid prototyping of visualization 
applications.  For repeated production use, AVS also allows you to 
save a complete network with all the user-defined interactive 
controls and layout specifications as a complete, finished 
application. 

The Extensible Visualization Environment

The capability to create additional modules for AVS, and even 
libraries of modules, enables you to extend the base capabilities of 
AVS for a specific application.  The ease of integrating additional 
modules into AVS allows you to create complex scientific and 
engineering applications with little or no programming.  You may 
easily incorporate your existing software programs as modules in 
AVS, integrating your in-house codes into the leading graphical 
visualization system resulting in a true integration of computation 
and visualization.

Distributed Visualization

AVS was designed from the outset to operate in  distributed, multi-
vendor, heterogeneous computing environments.  The support for 
remote module execution allows modules to execute on 
computational servers in the network.  X-terminal support allows 
AVS to display on 8-bit color X-terminals or workstations running 
the X-Window system.  These distributed capabilities enable you to 
incorporate AVS into the networked, distributed computing model 
already established today.  The two major architectural aspects that 
enable AVS to excel in a distributed environment are its modular 
architecture and its adherence to industry standards.

The Industry Standard for Visualization 

AVS is now available on the major UNIX-based workstation and 
visualization systems. These include computer systems from 
Convex Computer Corporation, Cray Research Inc, Digital Equipment 
Corporation, Evans and Sutherland, Hewlett-Packard, IBM Corporation, 
Kubota Pacific Computer Inc., Set Technology Corporation,  
Sun Microsystems, and Wavetracer.

AVS Features

AVS Geometry Viewer

The AVS Geometry Viewer gives you full control over a range of 
low-level hardware dependent graphics capabilities with simple 
menu-driven parameter selections.  The AVS Geometry Viewer takes 
advantage of all of the graphics functionality of the computer 
system on which it is operating.  On more advanced visualization 
hardware systems, for example, you have full control of wireframe, 
Gouraud or Phong shading; 16 individually controlled colored light 
sources, selectable as point, directional or spot lights; surface 
properties such as specularity and transparency; real-time 2D and 
3D texture mapping and anti-aliasing.

AVS allows you to create multiple windows with different views of 
the same geometric object or simultaneously display multiple 
objects.  Alphanumeric titles and labels in a variety of fonts can be 
added in screen or object space.  You can also create scenes with a 
hierarchy of objects and manipulate them individually or as one or 
more groups. These scenes can be saved, preserving all viewing 
selections for later re-display. You can create and save a sequence 
of images and cycle through the sequence to provide animated views 
of dynamic behavior - all in real-time. 

AVS Image Viewer

AVS provides a complete 2D and 3D image display capability, 
including real-time pan and zoom, region of interest operation, 
rotation and transformation, flipbook animation, and support for 8-
bit, 24-bit, and floating point images. Imaging filters include look-
up-table operations such as contrast stretching, pseudo-coloring and 
histogram balancing as well as data resizing operations such as 
interpolation, cropping and sampling.

Volume Visualization 

Through the use of pre-defined AVS networks, volume data may be 
read into and displayed by AVS, and then viewed using the 
visualization techniques described in the Geometry and Image 
Viewers.

A new class of algorithms has recently evolved for visualizing 
volumetric data, called 'direct volume visualization'.   An AVS 
module, tracer, implements a highly optimized ray tracing technique 
for three-dimensional volumes of cells. This means that it works as 
well for irregular field data and unstructured cell data as it does for 
regularly gridded voxel arrays.  Since it's implemented in portable 
software, it runs efficiently on all AVS platforms.  tracer can 
create high resolution, perspective views of colored and/or shaded 
volumetric data from any arbitrary orientation.

AVS Graph Viewer

The AVS Graph Viewer allows you to visualize and output your data 
in the form of 2D graphs, line charts, bar charts, or contour plots.  
There is a menu interface for selecting line types, types of plots, 
labeling and annotation, and for changing the scales and styles of 
grids and axis.  

Layout Editor

The Layout Editor enables you to easily and completely define the 
user interface.  The specific control parameters may be selected, 
and a custom interface may be defined, thus simplifying the default 
interface of a control panel for each module in a network.  You may 
also quickly assign user interface peripherals to control parameter 
widgets.  This is an extremely powerful productivity tool when 
tailoring AVS for specific end-user applications.

Data Probes

Coordinates and values at any given point are instantly obtained and 
displayed using data probes.  The probe is positioned using the 
mouse, and with a click of the mouse button underlying data values 
are instantly printed on the screen.

AVS Data Types

The following data types are available in AVS:

Field data		Volume data

- N-dimensional (scalar, vector)		Geometry data

- Uniform, rectilinear, irregular		Unstructured 
Cell  Data (1D, 2D, 3D)

- Physical-space coordinates		Chemistry data

Image data		User-defined data

Command Language Interpreter - CLI

The AVS Command Language Interpreter (CLI) is an ASCII language 
that can be used to drive most of the AVS system.  This allows 
advanced users and application developers to type AVS commands or 
develop scripts containing AVS commands.  This feature gives you 
the option of developing applications that communicate directly 
with the Command Processor without the Network Editor.  It can be 
used directly by you or indirectly from an AVS module to create and 
modify AVS networks, query and change module parameters, and 
control the user interface layout.

Labeling and Annotation

The ability to label and annotate images is very important, 
especially when producing hardcopy output for demonstration or 
publishing purposes.  AVS provides you with this required capability 
in all of its Viewers.


AVS Animator

In the process of doing day-to-day research, a scientist will 
frequently need to visualize events that unfold through time.  
Animation can be a powerful tool in viewing these events and 
presenting the results to colleagues.   The AVS Animator is designed 
to allow the scientist to produce a high quality animation in which 
control of object/camera/light placement and AVS module 
parameters can be handled on a per frame basis.  A sophisticated 
keyframe editor allows you to control these parameters.  Output can 
be sent to the display or recorded on various types of video 
hardware.

The Data Viewer

The Data Viewer is an AVS application comprised of an intuitive, 
easy-to-learn, user-extensible, point-and-click interface to the 
most frequently used visualization techniques. This application was 
designed with you in mind for learning about AVS.  The AVS Data 
Viewer is also a convenient shortcut for doing similar operations on 
a day-by-day basis, and can be used as an aide to building AVS 
applications for use by others. The full power and flexibility of the 
AVS Network Editor is still available for users who wish to 
customize their applications.

Unstructured Cell Data (UCD)

AVS support for UCD contains a subroutine function library and a 
collection of AVS modules for data input, filtering, and mapping 
operations.  UCD is used with finite element problems most 
commonly found in the Mechanical Computer Aided Engineering 
(MCAE) and Computational Fluid Dynamics (CFD) fields.  The set of 
UCD modules includes isosurfaces, streamlines, 2D slices, 
annotation, data probes, hedgehogs, and volume rendering.

Upstream Data

Upstream data is used in the Data Probes and in direct manipulation 
of mapper modules.  Upstream data passing allows data to flow 
"backwards" through a network for the purpose of ascertaining the 
value and coordinate information at a particular point.   This 
information is required for the mapper module (e.g. slice plane) or 
Data Probe to pass on in order to display or take other action with 
the information.

Module Library Management Tools 

Included in AVS is a set of tools to enable the creation, addition, 
deletion, and modification to modules and entire libraries of 
modules.

Continued Evolution to meet Future Visualization Needs 

Enhancements and extensions to AVS continue, building on this 
industry-leading environment to meet future visualization needs.  
With it's broad industry acceptance, AVS will undoubtedly continue 
to define the leading edge in visualization technology.  To learn more 
about AVS and the newest enhancements please contact AVS Inc at 
508 287 0100, any AVS vendor or the International AVS Center.

Stardent is a registered trademark, and AVS is a trademark of 
Advanced Visual Systems Inc.  UNIX is a registered trademark of 
UNIX Systems Laboratory.  X Window System is a trademark of MIT.
						
Newsgroups: comp.graphics.avs