Using OpenDX on MIRTH Simulator

Background

Open DX is a package similar to Iris Explorer, where 3D visualization is accomplished by wiring together modules that do individual tasks to make a 'net' (='map' in Iris Explorer). It used to be a commercial package made by IBM, but now it is free and open source (see http://www.opendx.org). One's initial impression after using Explorer is that the user interface is less user-friendly, but when you get used to it you will find that it is perhaps more powerful, with some nice features that are not initially obvious. Most of all it is FREE and can be installed on just about any Unix computer, including Macs with OSX.

Quick start

Try to avoid running dx on the front end, particularly with large data sets, as if several people do this it will run out of memory. The interactive nodes c0-0 to c0-2 are good ones to use (ssh -X to them).

Just typing in 'dx' will bring up a master menu with options like 'Import Data', 'Run Visual Programs' etc. Perhaps the most useful options for a beginner are 'Run Tutorial' and 'Samples', which brings up a choice of a large number of sample nets so you can figure out what the modules do and how to put nets together.

To create a new net or 'visual program', select the appropriate option from the master menu, or start dx using:

dx -edit

Ignore the two warnings about socket buffer size (click on them to dismiss).

If you already have a program and just want to run it, start dx using, e.g.,:

dx -program /usr/local/dx/modules_new/samples/StagReadX.net

StagReadX.net is an suitable net for visualizing Stag3D results and uses the new ReadStagField module. Copy to your own directory to edit. It shows how to do isosurfaces, slices, velocity arrows and a bounding box. Volume rendering can be accomplished just by wiring the output of 'AutoColor' to 'Image' (or 'Collect' to combine with other things).

Some hints:

• To add a module to the net, select it in the left panel then click somewhere in the net area to add it. To add a connection, click on the appropriate output tab of the first module, then drag the mouse down to the appropriate input tab of the second module and let go.
• The program does not automatically execute when you load it or change something, unlike in Explorer. To execute it do Ctrl-E. To put it into a mode where it executes every time you change some value, do Ctrl-;
• The Image module has several different modes: rotate, pan/zoom, etc. so you need to make sure you are in the right one. Ctrl-V brings up a convenient panel to change this and other things. Ctrl-f resets the view if you get messed up.
• Once it has read an input file, it will not re-read it, even if you 'execute'. So, if the file has changed on disk just reload the net by selecting it in "File->Recent Programs-> " and saying Yes when it asks if you want to save the net.

For detailed information on usage and programming

The full documentation in html can be accessed on MirthSimulator: in mozilla open file:

/usr/local/dx/html/allguide.htm

or you can find it on the internet at opendx.org:

http://www.opendx.org/support.html#docs