How to create a one-shot fade trigger? (light pulse)

[jezric]

Hey folks, what would be the best method to create a preset which when triggered does a single full bright to zero bright transition on a single fixture at a set speed. (basically, a one-shot OSC curve, or something like the sound trigger controls Attack/Release)

1 method I can see is using 2 presets (masked to just the single light I want to affect), 1 preset is full brightness, the 2nd preset is zero brightness. Then use the fade time on the Perform > Preset to set the fade time. Problem here is if that fade time isn't done fading and you trigger the preset again it fade back up, not the same full bright starting position.

Another method would be to use a SAW down OSC and then you would need to trigger the fixture off before the OSC repeats (don't see any way to have an OSC do a single pass), so this doesn't really work too well either.

Or use an Effect like a small gradient filled shape and have it animate across the fixture, but same as the OSC, I don't see a way to do a single pass, so again, doesn't really work.

Of course, I could do this with direct control over the DMX channel(s) I want to affect from my DAW via automation/MIDI CC/VST.

I'm pretty new to DMX but seems this has got to be a common operation for lights, like hit the preset it goes full bright and then fades at a set speed to zero bright.

Am I totally missing something here?

Thanks

[Quentin]

I'm only learning on SB, but with DMXIS I'd go the 2 preset route. "Full on" with a fade out time for the fade required, "Full Off" with zero fade time so even if you click "Full On" during the fade it will jump the fixture immediately back to full. Pity there isn't a way to "link" the two presets so the second one triggers after a set time, but perhaps you can do that with MIDI etc? (I don't use that as I'm running lights for amateur dramatics, so just simple sequences of lighting cues and me pressing the buttons!)

[jezric]

Yeah, can definitely do it with MIDI but man what a pain. SBA really needs a "one-shot" curve function (like OSC but without looping). So you could have a ramp down/ ramp up/ or up-down, etc. applied to a preset.

[jezric]

so even if you click "Full On" during the fade it will jump the fixture immediately back to full.

BTW, it doesn't seem to work this way, if you have a fade set on a preset, that fade carries over to the next preset if it's still fading. Seems like a bug to me.

[Quentin]

Just tried that in DMXIS and you're right - it does the same thing. Once a fade is running it continues, even if there's a change of preset. I'd never needed changes that fast, or at least not with fades.

[jezric]

I believe SBA derives from the same codebase as DMXIS, so not surprising. Hopefully the upcoming release Dave is working on will address these things.