Mapping moving pixels into a LED tube with Isadora.

  • Hi there all,

    Basically for an upcoming installation I'm trying to make a installation with WS2813 Leds. The thing is every single thing that moves creates multiple pixels (3 pixels) for example then the 1 pixel that I want.

    When a particle / shapes is moving I wish to have 1 pixel that is moving across the tube, instead of the 'ghost pixels' that I have currently. I included the patch that I'm working with.

    Any advice is welcome :)

    @bonemap (Know that you do a lot with moving shapes / particles)

  • Hi,

    don't know nothing about artnet, but in the shapes actor you set the hor. resolution to 240px and the width of the shape to 1 - but that is a percentage value, so your shape has a width of 2,4px...

    best r

  • Beta Gold


    It is also possible to address the channels individually so not with the matrix color send.

    I got this file from the forum. I think it is made by mark. there is one scene "test one pixel" that sends a value to one pixel. 

    ArtNet Send Tutorial.izz

  • @gertjanb


    The thing is that I change the shape based on the sound input of the installation. This method is not possible since I send multiple animations at the same time. (That travel, I use the particle actor for that.)

    Thanks for the input ! 

  • Tech Staff

    If I understand you correctly, you don't want the shape to blend across pixels as it moves.

    So you really want it to be placed only to exact pixel matching horz positions.

    Since your video is 240px wide and you have a placement range of 100 (%)

    You can divide 100 by 240 to determine the value of each pixel. 

    The attached file uses this method to place the line on a pixel exactly (note the line width is also this fraction)

    note: I add 1/2 the ratio to ensure the placement is centered.


  • Tech Staff


    does that patch help with your situation?

  • Hi there @DusX,

    Thanks for the extra note about the 1/2, that was exactly what I needed :)

    - Juriaan