pytuio 0.1

Tracking

The Tracking class should be used to initialize a socket connection for receiving the OSC messages from reacTIVision. It handles all incoming data and calls the appropriate functions, depending on the type of message.

When started it loads every possible profile from the profiles submodule and initializes a callback manager from the OSC module.

A simple example can be found in the examples directory in example1.py:

1. Import it:

   import tuio

2. Initializes the receiving of tracking data:

   tracking = tuio.Tracking()

3. Print all TUIO profiles that have been found and loaded:

   print "loaded profiles:", tracking.profiles.keys()

4. Print available helper functions, that can be used to access the objects of each loaded profile:

   print "list functions to access tracked objects:", tracking.get_helpers()

5. Prepare to receive the data in an infinite or event loop:

   try:
       while 1:
           tracking.update()
           for obj in tracking.objects():
               print obj
   except KeyboardInterrupt:
       tracking.stop()

1. You need to update the tracking information on each loop manually.

2. Access the tracked objects by using one of the helper function that return a list of these objects.

3. Stop the tracking manually on every exception to prevent socket errors

Objects

The objects submodule contains a series of classes that represent types of tangible objects. They all are subclasses of the also included objects.TuioObject. The following object types are defined at the moment:

1. Tuio2DCursor - An abstract cursor object, e.g. a finger. This object has limited information and is only sent by reacTIVision if the smallest possible fiducial marker was found: a point. In combination with a tangible table this can also be achieved by using fingers on the table surface.

   It has the following attributes:

   • sessionid - The unique sessionid it belongs to

   • xpos - The relative position on the x-axis

   • ypos - The relative position on the y-axis

   • xmot - The movement vector on the x-axis

   • ymot - The movement vector on the y-axis

   • mot_accel - The motion acceleration

2. Tuio2DObject - An abstract object representing a fiducial. This object has detailed information about its state and is sent by reacTIVision if a fiducial was recognized.

   It has the following attributes:

   • sessionid - The unique sessionid it belongs to

   • xpos - The relative position on the x-axis

   • ypos - The relative position on the y-axis

   • angle - The current angle in degrees

   • xmot - The movement vector on the x-axis

   • ymot - The movement vector on the y-axis

   • rot_vector - The rotation vector

   • mot_accel - The motion acceleration

   • rot_accel - The rotation acceleration

The TUIO protocol provides even more possible object types, depending on the purpose of the intactive surface, e.g.:

• 2.5D Interactive Surface - Tuio25DCursor and Tuio25DObject

• 3D Interactive Surface - Tuio3DCursor and Tuio3DObject

• raw profile - at the moment only dtouch specs are supported

But these profiles are left to be implemented by the user. Just have a look in objects.py and profiles.py and subclass the base classes there.

Profiles

The profiles submodule contains a number of abstract descriptions of what should happen if a certain object type is used. Depending on the desirable tangible object attributes you can customize the profiles for your own need.

For example, if you want to receive the data for a 2D tracking object you need to use the according profile, because it knows how to handle the dataset of this type of object.

Every profile subclasses from a TuioProfile base class that has the following required methods whose names originate from the name of the raw OSC message:

• set - The state of each alive (but unchanged) fiducial is periodically resent with ‘set’ messages. The attributes are sent as a list or tuple.

• alive - The ‘alive’ message contains the session ids of all alive fiducials known to reacTIVision.

• fseq - fseq messages associate a unique frame id with a set of set and alive messages

Other methods and attributes are:

• list_label - Defines the names of the helper methods that are automatically created while initialization of the Tracking instance and maps to the objs method of the used profile.

• address - Defines the OSC address to bind to the CallBackmanager and start listening to while starting the Tracking instance.

• objs - Returns a generator list of all tracked objects which are recognized with this profile and are in the current session. Though please use the helper methods whose names are defined in the class variable list_label.

OSC

This submodule does most of the heavy lifting of decoding the OSC messages used in the TUIO protocol and provides a convenient CallbackManager. It was written by Daniel Holth and Clinton McChesney.