Set of tools for livecoding networked visuals. Inspired by analog modular synthesizers, these tools are an exploration into using streaming over the web for routing video sources and outputs in realtime.
Hydra uses multiple framebuffers to allow dynamically mixing, compositing, and collaborating between connected browser-visual-streams. Coordinate and color transforms can be applied to each output via chained functions (see "basic functions" and "editing transformation functions" below.)
Note: experimental/in development. Right now only works on Chrome or Chromium, on machines with WebGL. I welcome pull requests as well as comments, ideas, and bugs in the issues section =]
Note: this repository is for the online version of hydra. Other pieces of hydra are published as separate modules:
- hydra-synth: synth engine of hydra as a standalone npm module
Experimental/in progress/not documented:
- rtc-patch-bay: networking logic of hydra as a standalone npm module
- atom-hydra: use hydra within atom
Other projects
Go to https://hydra-editor-v1.glitch.me
- CTRL-Enter: run a line of code
- CTRL-Shift-Enter: run all code on screen
- ALT-Enter: run a block
- CTRL-Shift-H: hide or show code
All code can be run either from the in-browser text editor or from the browser console.
render an oscillator with parameters frequency, sync, and rgb offset:
osc(20, 0.1, 0.8).out()
rotate the oscillator 1.5 radians:
osc(20, 0.1, 0.8).rotate(0.8).out()
pixelate the output of the above function:
osc(20, 0.1, 0.8).rotate(0.8).pixelate(20, 30).out()
show webcam output:
s0.initCam() // initialize a webcam in source buffer s0
src(s0).out() // render source buffer s0
If you have more than one camera connected, you can select the camera using an index:
s0.initCam(1) // initialize a webcam in source buffer s0
webcam kaleidoscope:
s0.initCam() // initialize a webcam in source buffer s0
src(s0).kaleid(4).out() // render the webcam to a kaleidoscope
You can also composite multiple sources together:
osc(10)
.rotate(0.5)
.diff(osc(200))
.out()
By default, the environment contains four separate output buffers that can each render different graphics. The outputs are accessed by the variables o0, o1, o2, and o3.
to render to output buffer o1:
osc().out(o1)
render(o1) // render the contents of o1
If no output is specified in out(), the graphics are rendered to buffer o0. to show all render buffers at once:
render()
The output buffers can then be mixed and composited to produce what is shown on the screen.
s0.initCam() // initialize a webcam in source buffer s0
src(s0).out(o0) // set the source of o0 to render the buffer containing the webcam
osc(10, 0.2, 0.8).diff(o0).out(o1) // initialize a gradient in output buffer o1, composite with the contents of o0
render(o1) // render o1 to the screen
The composite functions blend(), diff(), mult(), and add() perform arithmetic operations to combine the input texture color with the base texture color, similar to photoshop blend modes.
modulate(texture, amount) uses the red and green channels of the input texture to modify the x and y coordinates of the base texture. More about modulation at: https://lumen-app.com/guide/modulation/
osc(21, 0).modulate(o1).out(o0)
osc(40).rotate(1.57).out(o1)
Each parameter can be defined as a function rather than a static variable. For example,
osc(function({time}){return 100 * Math.sin(time * 0.1)}).out()
modifies the oscillator frequency as a function of time. This can be written more concisely using es6 syntax:
osc(({time}) => (100 * Math.sin(time * 0.1))).out()
To use screen capture or a browser tab as an input texture, you must first install the chrome extension for screensharing, and restart chrome. Desktop capture can be useful for inputing graphics from another application, or a video or website in another browser tab. It can also be used to create interesting feedback effects.
To install, go to http://chrome://extensions/ Click "Load unpacked extension", and select the "extensions" folder in "screen-capture-extension" in this repo. Restart chrome. The extension should work from now on without needing to reinstall.
select a screen tab to use as input texture:
s0.initScreen()
render screen tab:
s0.initScreen()
src(s0).out()
Any hydra instance can use other instances/windows containing hydra as input sources, as long as they are connected to the internet and not blocked by a firewall. Hydra uses webrtc (real time webstreaming) under the hood to share video streams between open windows. The included module rtc-patch-bay manages connections between connected windows, and can also be used as a standalone module to convert any website into a source within hydra. (See standalone camera source below for example.)
To begin, open hydra simultaneously in two separate windows. In one of the windows, set a name for the given patch-bay source:
pb.setName("myGraphics")
The title of the window should change to the name entered in setName().
From the other window, initiate "myGraphics" as a source stream.
s0.initStream("myGraphics")
render to screen:
s0.initStream("myGraphics")
src(s0).out()
The connections sometimes take a few seconds to be established; open the browser console to see progress. To list available sources, type the following in the console:
pb.list()
To run locally, you must have nodejs and npm installed. Install from: https://nodejs.org/en/
open terminal and enter directory
cd hydra
install dependencies:
npm install -d
run server
npm run start
go to https://localhost:8000 in the browser
FFT functionality is available via an audio object accessed via "a". The editor uses https://github.com/meyda/meyda for audio analysis. To show the fft bins,
a.show()
Set number of fft bins:
a.setBins(6)
Access the value of the leftmost (lowest frequency) bin:
a.fft[0]
Use the value to control a variable:
osc(10, 0, () => (a.fft[0]*4))
.out()
It is possible to calibrate the responsiveness by changing the minimum and maximum value detected. (Represented by black lines over the fft). To set minimum value detected:
a.setCutoff(4)
To set maximum:
a.setMax(10)
The fft[] will return a value between 0 and 1, where 0 represents the cutoff and 1 corresponds to the maximum.
To hide the audio waveform:
a.hide()
All of the available functions for transforming coordinates and color, as well as compositing textures, correspond directly to a snippet of fragment shader code. These transformations are defined in the file hydra/hydra-server/app/src/glslTransforms.js. When running locally, you can edit this file to change the available functions, and refresh the page to see changes.
For updated list of functions, see comosable-glslTransforms.js file in hydra/hydra-server/app/src/
- Syntax change from 'o0.osc()' to 'osc().out(o0)'. Note: old syntax still works
- multiple generator functions can be composited into each other:
osc(10) .rotate(0.5) .diff(osc(200).rotate(0.2)) .out() - Buffer can be an input to itself
- Multiple cameras can be specified using s0.initCam(1)
- synth logic exists as a separate module, hydra-synth
- added preliminary fft capability
- fixed some bugs in editor and camera
- Regl: functional webgl
- glitch.io: hosting for sandbox signalling server
- codemirror: browser-based text editor
- simple-peer
- Space-Time Dynamics in Video Feedback (1984). video and paper by Jim Crutchfield about using analog video feedback to model complex systems.
- Satellite Arts Project (1977) - Kit Galloway and Sherrie Rabinowitz
- Sandin Image Processor
- kynd - reactive buffers experiment
- Lumen app (osx application)
- [Vsynth (package for MaxMSP)] (https://cycling74.com/forums/vsynth-package)
- VEDA (VJ system within atom)
- The Force