Sometime last year (in 2012) I came across Graham Thorne’s instructional videos about how to transmit data from Isadora to Touch OSC. Here’s Part 1 and Part 2 – if this is something that interests you, I’d highly recommend by that you watch these two videos first.
While I didn’t have a TouchOSC project at the time that I was working on, it got me thinking about how interfaces communicate information about what’s happening in a patch, and how that information communicates to the operator or user of a given system. This year I’m working on the thesis project of Daniel Fine (an MFA student here at ASU), and one of the many challenges we’re bound to face is how to visualize and interact with a system that’s spread across multiple computers, operating systems, and controlling a variety of different systems in the installation / performance space.
To that end, I thought that it would be important to start thinking about how to to send control data to a TouchOSC interface, and how to then ensure that we can see relationships between different control values in a given control panel. That all sounds well and good, but it’s awfully vague. A concrete exploration of this kind of concept was what I needed to start planning, in order to more fully wrap my head around how idea could be more fully exploited in a performance setting.
In order to do this I decided that I wanted to accomplish a simple task with a TouchOSC control panel. On a simple panel layout I wanted the position of Slider 1 to inversely change the position of Slider 2, and vise versa. In this way, moving Slider 1 up moves Slider 2 down, and moving Slider 2 up moves Slider 1 down. In performance setting it’s unlikely that I’d need something this simple, but for the sake of testing an idea this seemed like it would give me the kind of information that I might need.
First let’s look at the whole patch:
The set up for this starts by configuring Isadora to receive data from TouchOSC. If you’re new to this process start by reading this post (or at least though the Stream Set-Up section) to learn about how to start receiving data in Isadora from TouchOSC. Next we’re going to use a few simple actors to make this happen. We’re going to use the following actors:
- OSC Listener
- Limit Scale Value (there are other ways to scale values, I just like this method as a way to clearly see what values you’re changing and in what way)
- OSC Transmitter
Once you have your connections between TouchOSC and Isadora set up you’ll want to make sure that you’ve isolated a single slider. We can do this by using the OSC Lister Actor. The OSC Listener reports the data coming from a given channel that you specific in the input inlet on the actor. The listener then sends out the transmitted values from the value outlet.
We have two sliders that we’re working with – Channel 1 and 2 respectively (they also have names, but we’ll get to that later). We first want to look at Channel 1. We’re going to set the OSC Listener actor to channel 1 and then connect the value output to the value inlet on a Limit-Scale Value Actor. The Limit-Scale Value Actor allows you to change, scale, or otherwise remap the floats or integers to a new range of values. This is important because TouchOSC uses normalized values (values from 0-1) for the range of the sliders in its control panels. In order to create an inverse relationship between two sliders we want to remap 0-1 to output as values from 1-0. We can do that by enter the following values in the inlets on the actor:
- limit min: 0
- limit max: 1
- out min: 1
- out max: 0
The remaining step is to connect the output from our Limit-Scale Value Actor to an OSC Transmit Actor. The OSC Transmit Actor, like its name suggests, transits data wrapped in the OSC protocol. In order to fully understand how this data is being transmitted we need to know a few things about this actor. In looking at its components we can see that it is made up of the following inlets:
- UDP Addr – UDP address. This is the IP address of the computer or device that you’re taking to. You can determine what this address is in TouchOSC by looking at the info panel. Imagine that this is the street name for a house that you’re sending a letter to.
- Port – this is the port on the device that you’re sending data to. It’s important that you know what port you’re trying to talk to on a given device so that your message can be parsed. If the UDP Address is the street name, the port number is akin to the house number that you’re trying to send a letter to.
- Address – The address in the case of TouchOSC is the individual target / name of an asset that you want to change. Each of the sliders and buttons on a TouchOSC panel have a name (for example – /1/fader1), the address is how you tell Isadora what slider you are wanting to change. You can determine these names by looking closely at your Stream Set-up when you’re connecting your device to Isadora. To follow with our letter sending metaphor above, the Address is the name of the person you’re sending the letter to.
- Use Type – this allows us to toggle the sending mechanism on and off.
- Value – this is the value that we’re transmitting to our other device.
To use the OSC Transmit actor we need to fill in all of the appropriate fields with the information from our mobile device. You’ll need to specify the UPD Address, the Port number, the Address, and connect the value out form our Scale-Value actor to the value inlet of the OSC Transmit Actor.
In this test I started by having fader1 drive fader2. Once I got this working, I then repeated all of the steps above, for the other fader – if you look closely at the full patch this will make more sense. The resulting interaction can be seen in the gifs below.