This is a chromakey user actor based on a GLSL green-screen shader I found on I have made the inputs to the shader available to be manipulated in Isadora. I then embedded the GLSL shader inside a user actor to ease in sharing it.


Notes on using this shader:


The higher the color number the more of that color is removed. So if you only wanted to take out a solid green, you may set Red to 0, Green to 1, and Blue to 0. Playing around with these numbers you should be able to take out other colors that are a mix of RGB as well.


The actor defaults to being set up for green screening.


The padd(ing) setting is fiddly and may not really ever need to be set much higher than .05


The Threshold setting is also very sensitive and may not need to be very high to get a big effect.


All of the settings ending up feeling like they need to be quite precisely set, but I find that the key it provides is quite nice once it is tuned in and doesn’t seem to be very taxing to my system.


You may find and HSL actor or a contrast adjustment actor in between your source and this actor may help cut out the greenish frizzy bits on the edges of your content.

Free Clouds patch

I made a simple patch that used clipart style ‘cardboard’ clouds to float across the screen.


You can change the images to anything you want. This a nice and simple patch but it might be interesting for someone who is learning.

ZoomOSC Name To Video

This is a project using a few user actors for dealing with ZoomOSC and auto-cropping the participants and creating scenes from them. It makes heavy use of Global Values by setting them for the panner values for every frame in every gallery size of ZoomOSC. It also uses Global Values to retain all the data associated with each person in the meeting. This combination allows us to easily fine the right cropping for any given user. The User Actor that calculates the cropping is “Calculate Frame Croppers” which is on the OSCListen scene. The User Actor “Gallery Video Broadcasters” sets a broadcaster for each of the cropped videos from the scraped screen. In the “Sample Scene” scene, we have the pair of User Actors: “Name To Video”, which takes names as input and sends vid-gpu as output for each of the names participants in the meeting. The “Layout” actor, passes each of those videos to projectors for layout.


Version 1.1.0 changed to passing JSON data rather than individual numbers so that it can scale up with fewer lines drawn.


This requires plugin: JSON Parser


I added a checklist to the OSCListn page:


1. You must have a Pro license for ZoomOSC to receive the /list/ message

2. You must turn OFF self-view in the gallery

3. You must set Settings / Additional Settings / Gallery tracking mode to ZoomID

4. If you ever need to reset the frames, hit the ‘d’ key to send a /list/ command

5. You must install the Isadora plugins:

Screen Capture (Public Alpha)

JSON Parser / JSON Bundler


Ableton Live – MIDI Program Change

This User Actor accompanies the Control Isadora From Ableton Live Using MIDI tutorial found in the Tutorials – Scripting, Sensors and Interfacing section of of the Troikatronix website.


The User Actor will watch for MIDI Program Change Messages sent from Ableton Live.

Three output options are available.

1: Direct MIDI value

2: Value as shown in Ableton Live (offset by 1 from MIDI)

3: The MIDI value as a percentage

You can change the outputs available by clicking the Actors Eye icon, and selecting the visible outputs.

DX – Rotate Canvas

Do you ever need to change the orientation of an image in Isadora?


We have spin and we have flip, but these don’t change the aspect of the canvas. They manipulate the image within the current canvas dimensions. This isn’t always what we need. Sometimes we don’t have time to open the image in our photo editing software and rotate the document.

So, I made a quick little User Actor that allows you to rotate any video/image 90,180, and 270 degrees creating a new canvas aspect ratio.

Bonemap – Audio Frequency 7 Band Analysis

Audio Frequency Analysis User Actor and demonstration patch

Frequency Range – Frequency Values

  1. Sub-bass 20 to 60 Hz
  2. Bass 60 to 250 Hz
  3. Low midrange 250 to 500 Hz
  4. Midrange 500 Hz to 2 kHz
  5. Upper midrange 2 to 4 kHz
  6. Presence 4 to 6 kHz
  7. Brilliance 6 to 20 kHz

More information available inside the user actor ‘7 Band Audio Frequency Analysis’.

The patch demonstrates a user module that amalgamates numerous 3D Line actors to build an audio generative pattern.


IzzyKorg is a small wrapper around the most used MIDI Controller out there, the KORG nanoKONTROL 2. In my day to day practice, I use this little user actor for my students so they can quickly add a MIDI controller to there patch.

All wrapped with a simple JSON interface that allows you to target the elements by doing [category]:[field]

For example, the Knob on the first fader is “fader1:knob”.

Please be aware that I didn’t add any feedback from the patch back to the controller in this version.


  • Install the required plugins from Mark called JSON Parser / Bundler
  • Put the User Actor in your Global User Actor Toolbox, that way you will always have it ready to go!
  • For detailed instructions on how it works, please look inside the user actor by clicking on it 🙂

Contact & License

Feel free to use it for any work / commercial or non-commercial without the need for credit.

If you have questions feel free to send me an e-mail at hello[@]

Tutorial: Basic Motion Tracking

In this mini-tutorial by L Wilson-Spiro you’ll learn how to do basic motion tracking with the Eyes actor

Use motion tracking data from the Eyes actor to affect other actors in your Isadora Patch, and combine the Freeze and Effect Mixer actors to make motion tracking easier.


Tutorial: Alpha Mask

In this mini-tutorial by L Wilson-Spiro you’ll learn how to use the Alpha Mask actor.

It starts with simple steps using just the Shapes and Alpha Mask actors, and proceeds to gets more complex, showing how to make alpha masks explode into pieces, video static effects, a moving video spotlight controlled by your mouse that inverts colors, and how to use background subtraction to create a ghost effect.