Dial or slider used to control zoom - changing the maximum control value has no effect

  • Hi

    In my control interface I am including position and size (zoom) controllers to allow the operator to easily control the video display without having to fiddle with the data projector. A slide or dial controller used to adjust zoom on the CI projector outputs from 0 to 1000, regardless of what I set the maximum control value at in actor properties. Any advice?
  • Izzy Guru

    'Scale value actor' should help you with that one.

    Set the input to 0-1000
    and the output to 0-100 (or whatever you require)

  • Ok, that's a method. But Scale Value only goes up to 100%, which means I can never zoom in beyond full size; I can only zoom out. Instead, I'm now using a calculator actor to output a scaled value between 0 and 200 to receive and pass the value unchanged (it adds zero) from the dial control to the zoom input.

    So, is this a matter of my misunderstanding or is it a bug? The dial output does change according to settings but once it hits the zoom it always reads as 1 - 1000\. Weird.
  • Izzy Guru

    Works fine for me, I set the max zoom in the ci projector to 200 and when the slider reaches the top it doesn't go beyond 200.

    See attached file.

    Michel 29d705-previewzoom-test.izz

  • Thanks, Michel.

    I didn't look at the zoom scale settings on the CI Projector. *facepalm* That fixes the value change coming directly from the control actor. However, the value from the calculator actor is not being scaled. IE, with the zoom max set to 1000, value 50 from the dial results in value 500 at the zoom, but value 50 from the calculator is left as 50 on the zoom. So it seems that controller values are scaled but values from non-controller actors are not scaled...

  • Here's the key point about scaling: if any of the scale or limit values (output = Limit Min/Limit Max, input = Scale Min/Scale Max) are MIN or MAX, no scaling will occur. Why? MIN or MAX essentially represent "infinity" -- when you have infinity as a limit, it is impossible to calculate the scaling.

    My guess is that with your Calculator actor, the 'Limit Min' and/or 'Limit Max' are set to MIN or MAX. Click on the word 'output' on the Calculator to look in the inspector box and see. 
    Understanding scaling is the key to accessing the full power of Isadora, especially with regard to interactive setups. it is a really good idea to watch the two scaling tutorials on YouTube -- you can access those directly from the Help menu in Isadora.
    I've attached an example file for you to look at, with several comments.
    Best Wishes,


  • Thanks, Mark. I'm quite sure that's it. I'll check out those videos again,