xv was an integral part of day-to-day research activities. Basically, all we did all day was solve differential equations. This involved a ton of simulation, plotting, data analysis, and visualization.

xv was this really modest tool that did one thing really well--make it easy to look at images. You could browse images, adjust color maps, flip between images, and so forth.

If you walked by a colleague's workstation on any given day, you'd see like 20 instances of xv running at once. 2/n?

I'd recall days where a group of us would be huddled over some workstation flipping between images in xv. Somebody might even hold a ruler up to the monitor to measure distances between features of two images as we flipped back and forth.

Of course, there was the problem of finding "that image" from last month. Is it in the "old2" directory or the "new3" directory? Or the "new_old2" directory. Ah hell. So, you'd fire up xv to go searching around for it. 3/n?

Needless to say, xv was one of those tools that was all about "doing the work." It wasn't flashy. It wasn't freaking Photoshop. It was effective. And it worked on my SPARCStation with 16MB of RAM.

Seriously, we used the hell out of xv in our research group. 5/n?

Anyways, sometime around 1992, computational power had increased to a point where we started to do a lot more of our simulation work in 3D. For example, running molecular dynamics simulations on a 250x250x250 atom cube of some material.

This had nothing to do with xv, but it had a huge impact on all of the other tooling related to data visualization. Specifically, dealing with large datasets, interactive exploration, and even being able to reason about what you were looking at. 6/n?

Of course, nobody was able to visualize a 15 million point 3D dataset on their SPARCStation.

Naturally, the "CS" solution to this problem was to throw infinite money at it. So, at some point, a shiny million dollar SGI showed up over the computer center and you could go use that (which we did).

Of course, they put it behind glass in the computer room where people could gawk at it along with the nearby Connection Machine. 7/n?

So, sure you could go use the SGI, but doing so meant a) you had to actually had to leave your office b) You had to go outside in the blazing heat (or a midday thunderstorm), and c) you had to bring a sweater because you had to sit next to it in the freaking machine room.

Of course, this all assumed that the machine wasn't already being used for a HS student demo or someone playing "driving simulator." Or showing off that dumb Unix file browser thing from Jurassic Park. 8/n?

And if you brought your colleagues along for an SGI visit, half of the conversation was like "WHAT?!?!"

Because, as mentioned, you're all sitting in the computer room next to a giant supercomputer that needs cooling.

But, it all looked pretty sweet. I will grant you that. The kind of setup that would make a funding manager take one look and say "it'd be even sweeter looking if we had a bigger SGI than Livermore." 9/n?

Anyways, while all of this is going on, a more diminutive, yet still kind of cool looking SGI shows up in the corner of the post-doc/grad student bullpen. A mere $250K machine. It too can play Driving Simulator.

It sort of works but a) you now had to FTP gigabytes of data from the computer center to local storage over 10Mbit ethernet. b) There's never enough local storage. c) Visualization takes forever. d) Nobody else can use it while it churns. It kind of sucks. 10/n?

But, the resulting pictures look kind of awesome. Bad ass really. Realistic lighting. Anti-aliasing. All of the molecules look spiffy--like rendered billiard balls. Stuff, you'd definitely want in a PowerPoint presentation to be shown on the big screen at a Supercomputing conference.

Why, what are we talking about again? Oh yeah, xv. Let's get back to xv... 11/n?

Actually, before I do that, let me add that this "big SGI in the machine room thing" eventually morphed into a "let's make a holodeck for doing VR!" thing. Yeah, because that's exactly what scientists want. Freaking VR! To use when you're able to sneak in sessions between the HS student tours and you're prepared to take the afternoon off afterwards to sooth the resulting migraine.

Dear metaverse, 1996 called and wants its dumb idea back. Thanks.

I digress. 12/n?

So, xv had a special "polling" mode that you could use to make it continuously watch a file. If you were viewing the file and the file changed, then xv would update the displayed image.

This was the secret sauce for making real-time dashboards.

You'd have your physics code dump some kind of output file every so often. Then, you'd stick pgplot or some other tool on a crontab to make an image. Have xv poll the output file.

It worked great and involved almost no coding. 14/n?

It was generally understood that no workstation would ever be idle in the group--someone was always solving differential equations somewhere. Usually for tens to hundreds of hours at a time.

So, when I say you'd sometimes see someone running 20 copies of xv, they were often running it as a dashboard. Spin up your physics code on 20 machines and then spin up 20 copies of xv to monitor progress. It was pretty hacked together, but it worked decently well. 15/n?

In light of this, we got to thinking... "what if we could just make our big supercomputing code directly produce output images?" If we could do that, maybe we could wire up xv on the back-end of it and turn it into a cheap "visualization platform."

The only problem with this is that we were working on the Connection Machine. I wasn't aware of a vis/graphics library that we could use for this. And whatever we used, it would have to be extremely lightweight due to memory concerns. 16/n?