Afterglow
A live-coding lighting controller, building on the Open Lighting Architecture with Clojure and bits of Overtone.
Install / Use
/learn @Deep-Symmetry/AfterglowREADME
Afterglow
Documentation Overview
This page provides an introduction in how to install and use Afterglow. The Developer Guide goes much deeper, and there is also API documentation. For more interactive help, the Afterglow stream on Zulip is the place to start, and if you want to see (or contribute to) more structured and lasting community-driven documentation, there is also a project wiki.
Why Explore Afterglow?
tl;dr—show me? Check out the Show Control pics and performance video.
As suggested by the live-coding orientation mentioned above, which is designed to let you inject your own code right into the frame rendering process, Afterglow takes a very different approach to controlling light shows than other software. It won’t be right for everyone, but will be extremely compelling to a particular niche. The early stages of its rendering loop can offer higher levels of abstraction than the usual DMX channel value or fixture function (although those are fully supported too):
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You can express your desired results in terms of an abstract color, including support for the hue-saturation-lightness model, which is great for algorithmic looks, and have it translated to whatever color channels (or color wheel) your fixture supports.
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Groups of moving heads can be told to face particular directions by specifying parameterized vectors, or to aim at a particular point in space, and Afterglow figures out how to translate that into DMX control values given its understanding of the fixture and where, and at what angle, you hung it.
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There are a variety of oscillators which can efficiently drive effect parameters.
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You can also create complex effects, with adjustable parameters that can be controlled through a rich binding to an Ableton Push or Novation Launchpad family controller, or via Open Sound Control (OSC)—even wirelessly from a tablet or smartphone.
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The timing of effects is pervasively influenced by a deep notion of musical time, with support for synchronization via MIDI clock, Traktor Beat Phase, or Pioneer Pro DJ Link beat grids.
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You can even host Afterglow within Cycling ‘74’s Max visual interactive environment.
If any of this sounds interesting to you, read on to see how to get started!
Table of Contents
- Why Explore Afterglow?
- Installation
- Status
- Getting Help
- Usage
- Troubleshooting
- Bugs
- What Next?
- Release Checklist
- Tasks
- License
Installation
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Install OLA. (On the Mac I recommend using Homebrew which lets you simply
brew install ola). Once you launch theoladserver you can interact with its embedded web server, which is very helpful in seeing whether anything is working; you can even watch live DMX values changing.:wrench: If you are installing Afterglow on Windows, see the Wiki discussion about OLA options.
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For now set up a Clojure project using Leiningen.
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Add this project as a dependency:
:wrench: If you were using older releases of Afterglow and installed CoreMIDI4J in
/Library/Java/Extensions, you need to remove it, because Afterglow now embeds an improved version and uses it when necessary.
If you want to run Afterglow as a standalone executable, you can
download the executable überjar from the
releases page.
For an example of a project which uses Afterglow as a dependency, as described above, see afterglow-max, which hosts Afterglow inside Cycling ‘74’s Max.
Status
Although Afterglow is far from finished, it’s ready for the world to start exploring, and helping decide directions in which to grow next (as well as identifying areas where the documentation needs clarification or reinforcement).
Most of the crazy ideas have panned out and been implemented, and I am fleshing out the basic details needed for everyday use. The examples are starting to be intriguing and informative, and the Developer Guide is getting substantial. The modeling of fixtures, channels, etc. is coming together nicely, though there may be a few more changes.
There is now an embedded web application, which is growing into a show control interface for people who are not Clojure hackers, and a useful adjunct to the Ableton Push and Launchpad family control surface interfaces. Each is explained in the documentation link above. Afterglow also includes the beginnings of a show visualizer for designing and working on effects without having to physically hook up lights (a proof of concept, really, at this point). This is implemented in WebGL using a volumetric ray tracer and looks quite promising, at least for a small number of fixtures; it will probably overwhelm the graphics processor on most systems once you add too many lights. However, the framework can be used by someone who actually knows OpenGL programming to build a more scalable preview (albeit one that probably doesn’t look quite so photo-realistic with beams impacting drifting fog). This is an area where I would love some help if it sounds interesting!
Getting Help
<a href="http://zulip.com"><img align="right" alt="Zulip logo" src="doc/modules/ROOT/assets/images/zulip-icon-circle.svg" width="128" height="128"></a>
Deep Symmetry’s projects are generously sponsored with hosting by <a href="https://zulip.com">Zulip</a>, an open-source modern team chat app designed to keep both live and asynchronous conversations organized. Thanks to them, you can <a href="https://deep-symmetry.zulipchat.com/#narrow/stream/318697-afterglow">chat with our community</a>, ask questions, get inspiration, and share your own ideas.
Usage
The rest of this document primarily provides an introduction to the configuration of Afterglow from the command line and text files. The show control interface is explained in the web and Push sections.
Although you will often want to use Afterglow from a Clojure repl, you
can also bring it up as an executable jar, and run it using java -jar with command-line arguments:
> java -jar afterglow.jar
