[dtristram]

Hi, David Tristram here. founding member of Raster Masters, 1990's computer graphics performance ensemble. As @hopkins has mentioned, we used high end Silicon Graphics workstations to create synthetic imagery to accompany live music, including notably the Grateful Dead, Herbie Hancock, and Graham Nash.

After many iterations I'm currently working mainly in 2D video processing environments, Resolume Avenue and TouchDesigner. The links here are inspiring, thanks for posting.

[DonHopkins]

Who were the other people in Raster Masters, and what crazy stories from Grateful Dead concerts can you tell? ;)

Every time I've ever plugged in a modern projector into a laptop at a presentation it's so stressful, like rolling the dice if the screen will ever come up. What kind of a projector and calibration and preparation did it take to project live hires SGI video onto the screen above the band?

[actionfromafar]

I would guess either https://en.wikipedia.org/wiki/Eidophor or https://en.wikipedia.org/wiki/Talaria_projector https://www.ebay.com/itm/225229726689

https://web.archive.org/web/20250124121654/https://www.ebay....

[DonHopkins]

Wow glad I asked, thanks for the links -- TIL about wobbulators! Definitely on my xmas shopping list for my retro electronics freak friends.

https://en.wikipedia.org/wiki/Talaria_projector

>RGB color separation and processing is obtained using vertical wobbulation of the electron beam on the oil film to modulate the green channel and sawtooth modulation is added to the horizontal sweep to separate and modulate Red and Blue channels. The optical system used in the Talaria line is a Schlieren optic like an Eidophor, but the color extraction is much more complex.

https://en.wikipedia.org/wiki/Wobbulator

>A wobbulator is an electronic device primarily used for the alignment of receiver or transmitter intermediate frequency strips. It is usually used in conjunction with an oscilloscope, to enable a visual representation of a receiver's passband to be seen, hence simplifying alignment; it was used to tune early consumer AM radios. The term "wobbulator" is a portmanteau of wobble and oscillator. A "wobbulator" (without capitalization) is a generic term for the swept-output RF oscillator described above, a frequency-modulated oscillator, also called a "sweep generator" by most professional electronics engineers and technicians.[1] A wobbulator was used in some old microwave signal generators to create what amounted to frequency modulation. It physically altered the size of the klystron cavity, therefore changing the frequency.

Samwell & Hutton Ruggedized CT501 Wobbulator (1968) NSN: 6625-99-620-2403

https://www.ebay.com/itm/267012403603?_skw=wobbulator&itmmet...

[relaxing]

Do you have links to this work we could see?

[DonHopkins]

ElectroPaint and other Raster Master performances were featured in the Infrared Roses video:

https://en.wikipedia.org/wiki/Infrared_Roses

Infrared Roses is a live compilation album by the Grateful Dead. It is a conglomeration of their famous improvisational segments "Drums" and "Space". The ElectroPaint stuff begins around 11:00, but the Raster Masters did all kind of different stuff in parallel and mixed it all together in real time. I remember them describing some "recursive texture map" feedback too, which only ran on high end SGI workstations.

https://www.youtube.com/watch?v=gkhr23asO-M

Wired: Raster Masters: Enough with virtual reality -- virtual hallucinations?

https://www.wired.com/1994/06/raster-masters/

Electropaint on SGI Indy: A capture of the great screensaver electropaint on an SGI Indy. There is no sound (originally I had Mahavishnu Orchestra's "Miles Beyond" but youtube flagged me for it), but feel free to blast your own music while watching:

https://www.youtube.com/watch?v=StA81MNuqB8

6 minutes of ElectroPaint:

https://www.youtube.com/watch?v=ObdtoLuSaWM

SGI IRIX ElectroPaint Screen Saver:

https://www.youtube.com/watch?v=gbWpsrNYfaQ

Panel Library and ElectroPaint source code:

http://66.111.2.18/pub/The_Unix_Archive/Unix_Usenet/comp.sys...

Some of David's more recent stuff:

https://www.facebook.com/groups/106720642819222/posts/222074...

>In the spirit of J-Walt's intro message, I'm David Tristram, somewhat of a pioneer in the use of real-time graphics for live performance. Author of Electropaint and Electroslate live performance instruments, and founding member of Raster Masters. Toured with Grateful Dead, developed performance system for Graham Nash and Herbie Hancock.

>I'm just playing with things these days, most recently making music with a small modular system and experimenting with very simple looping visuals in an investigation into the perception of visual rhythms. Here is my most recent test.

https://www.facebook.com/dtristram/videos/10159683105214837

[louky]

I think I saw some of your work at a few Dead shows in ~1992