Graphics and Visualization Software at DKRZ

The traditional method to look at climate model data is to select two dimensional slices of the data volume and to display physical quantities using isolines. With growing computing power and the availability of colour devices in the last decades it became popular to fill the areas between the isolines with solid colours: filled contours. Vector quantities are displayed using arrows or streamlines. An overlayed geographical map simplifies the interpretation of the graphics.

For this type of applications, DKRZ offers NCAR Graphics and GrADS to its users.

The large data volumes produced by todays climate models are not easy to overview and to analyze. The use of 2 D graphical tools within a time dependent 3 D data volume can be limiting in respect to the understanding of 3 D processes or to find the essentials of the data. As a help to solve this problem, DKRZ offers its users the interactive 3 D visualization toolsAVS, Wavefront Data Visualizer and Vis5D.

NCAR Graphics

NCAR Graphics (GIF,17 KB)

A graphics package, especially made for the needs of meteorologists has been developed at NCAR, the National Center for Atmospheric Research in Boulder, Colorado: NCAR Graphics. A FORTRAN subroutine library (also available for C) is currently the most important part of the software. The user has to write a FORTRAN application or to apply a FORTRAN program written by somebody else in order to use NCAR Graphics.

One of the most important advantages of NCAR Graphics compared to other utilities is the level of detail of all elements of the graphical output which can be influenced by the user. Of course it will need some time until new users of the package know the most important routines, utlilities and parameter settings.

More information on NCAR Graphics is available at: NCAR Graphics Home Page. And information about the National Center for Atmospheric Research is located at: NCAR Homepage.

NEW and quicker for local users: DKRZ is an official mirror site for the interactive documentation for NCAR Graphics Version 4.0 . These online documents replace the printed documentation for older versions of NCAR Graphics.

GrADS

GrADS (GIF,36 KB)

The Grid Analysis and Display System is a public domain software package. It is designed especially for gridded meteorological data and meteorological station data. Most data produced at DKRZ are gridded and can be analyzed and plotted with GrADS. While the GrADS data model supports time dependent 3 D data volumes, only one and two dimensional display types are available.

The degree of interactivity provided by GrADS is very high compared to that of the current version of NCAR Graphics. The GrADS user interface is a command language which means that commands are executed instantaneously. The scripting support allows the development of interactive applications to fit the needs of end users. The built in animation capabilities help to visualize time dependent processes.

The DKRZ user consulting group offer a reference card for grads commands and a second card for the grads scripting language . The GrADS Homepage (in Maryland, USA) is another place with information on the subject.

AVS - Advanced Visualization System

AVS Network Editor (GIF, 158 KB)

AVS is not only a 3 D visualization program. It is a kind of interface builder which allows the parallel distribution of applications to multiple processors or workstations and can be customized using C or FORTRAN modules. With AVS, a visualization application can be developed without writing any program code. The Network Editor allows programming simply through mouse actions. Modules from a module library can be copied to the working area and connections between these modules can be made. The resulting network controls the data flow. Virtually anything can be done with AVS, but it could really take some time until the desired result is reached exactly.

Hundreds of public domain modules expand the large built in tool set of AVS. Have a look at our anonymous ftp server if you need more than the standard modules. The source of these modules is the International AVS Center (IAC). Another web site with information on AVS is the AVS Inc. itself.

Have a look at some AVS animations produced at DKRZ

Wavefront Data Visualizer

Wavefront Data Visualizer (GIF, 85 KB)

This is a program designed for the interactive 3 D visualization of 3 D data sets. Most state of the art tools can be created and activated with a few mouse clicks. One of the most outstanding tools of Data Visualizer is the particle advection tool, which does not seem to be currently available in the same quality within other visualization systems. An example of an application of this tool with time dependent data is the animation of a simulated volcano eruption.

Additional examples and animations...

More information about Wavefront products: Wavefront web site.

Vis5D

Vis5D (GIF,106 KB)

Vis5D, which stands for Visualization of 5 Dimensional data, is also a public domain visualization program designed for meteorological model data. 5 D means: the data is three dimensional, time dependent and can contain several physical quantities. The user interface of Vis5D is simple: it consists of a 3 D viewport and buttons to create the desired tools for each physical quantity.

Vis5D doesn't necessarily require powerful 3 D hardware to run, but it makes life much easier if you have it. Compared to other 3 D visualization tools, Vis5D is then very good for real time applications.

Vis5D has been developed at the Space Science and Engineering Center (SSEC) in Madison/Wisconsin as part of the visualization project . The official european mirror of the software devoloped within this project is located at DKRZ. There you will find the source and binaries of Vis5D.