We will use a sensor to track the movement of a panel and project content positioned on it.

We will see how the sensor is used to move a panel and track the media on it. We will then see how to make an x-ray effect to reveal an image.
We will finally see how to use the tasks to change cue according to the position of the panel.
And for those who want to go further, we will show the possibility of wedging a media on a rotating panel.

For this purpose we will use one of the following sensors of your choice:

  • Cable reel with absolute Posital encoder. Here is the “link”: http://support.modulo-pi.com/modulo-player-manual/1/en/topic/rotary-ip on the documentation.
  • “Phidgets cable reel”: https://www.phidgets.com/?tier=3&catid=104&pcid=84&prodid=1002 and encoder quadrature. See the “link”: http://support.modulo-pi.com/modulo-player-manual/1/en/topic/quadrature-encoder on the documentation.
  • TeraRanger measuring laser. Here is “the link”: http://support.modulo-pi.com/modulo-player-manual/1/en/topic/teraranger to the documentation.
  • and the low cost version with a simple slider by gluing a mini panel on it. Here is the “link”: http://support.modulo-pi.com/modulo-player-manual/1/en/topic/slider-60mm to the documentation.

Fixing the projector:

To follow a panel in image, it is imperative that it is seen from the projector as a basic offset on an axis. We will therefore try to have a movement as parallel as possible to the axis of the projector. If this is not the case, it is necessary to use warping in Keystone mode (Keystone mode is important because it allows to have a homogeneous spread in pixels, otherwise the panel will be in the right place on each side but not in the middle of the movement). For this reason:
The Grid sight is displayed on the output.
We’re going to move the left panel, we’re moving the left corners of the warping.
The panel is moved to the right and the right corners of the warping are shimmed.
Then move the panel from left to right to see if the image is correctly spread over the entire movement.


Picture 1: empty
Cue 2 : media Test Pattern at the ratio of the panel in pixels : the panel is placed on the left and the number of pixels of the media is adjusted to display an image only on the panel.
Cue 3: animated video media: the crop on the layer is used to display images only on the panel
Cue 4: layer 1: Test Pattern media at the ratio of the panel in pixel in alpha mask mode, and layer 2 video in HD not cut


We create a digimap, we select it, we add a patch and we edit it. we choose Playlist/ we choose the playlist 1/ we choose cue 2 and layer 1.
The sensor device is used in trigger mode.
We’ll first wedge cue 2 with the movement of the target.
We put the panel to the left. We’re going into simulate A mode.
click on the cross to read the value of the sensor.
we move the value in out A at sight until the image is fixed on the panel.
We put the panel to the right. We’re going into simulate B mode.
click on the cross B to read the value of the sensor.
we move saw the value in out B until the image is fixed on the panel.
we go back to simulate in none. we click on “evaluate” to calculate the coefficient and the offset.
The panel can normally be moved from left to right and the image must remain on the panel.

We now want to apply the same effect on cue 3 and cue 4. We will control the digimap on it: Two options, either we add one Digimap per cue and we make the calibration again each time (a little long), or we will simply use global position x a instead of position x: We will thus apply a global offset in x to all cues. So we need only one digimap for the whole show. We will therefore simply edit the patch and replace position x by global position x. We do a reset offset.

All cues can now be tested, including the x-ray cue.


you can also trigger a task when the panel enters an area. For example, you can have several cues on the playlist, and depending on the position of the panel you can trigger the launch of a different cue depending on the position of the panel.

We will create several tasks, one per cue to launch.
We add a Modulo Player device and use this device to launch cue 2 from task 1, launch cue 3 from task 2, and launch cue 4 from task 3.

We will then add a task trigger using the sensor. We will choose a row for each task to trigger the corresponding cue. To know the range values to be entered for each interval, go to the device tab on the sensor, move the sensor and note the range values to be entered in the task trigger.

Rotation of a panel on an axis:

It is also possible to use an “encoder”: https://www.phidgets.com/?tier=3&catid=103&pcid=83&prodid=997 with the panel glued on top centred on the projector side. This must be connected to the “next” device: http://support.modulo-pi.com/modulo-player-manual/1/en/topic/quadrature-encoder.

we will create a digimap with the quadrature encoder as a trigger and which acts on the rotation of a layer. We need to put this layer in Center mode instead of Top-Left.

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