Issue with Isadora, Syphon, TripleHead2go Digital Edition, Macbook pro

  • An observation, which only partly is due to Isadora. I ran the above (subj) setup recently, and saw that in some cases the video output would simply quit, letting projector show a nice company logo. I had two scenes, both using syphon inputs into Isadora. One syphon input would send a kinect depth field into Isadora, affected by realtime sound (an early sketch here: Second syphon input would send a one million particles sound reactive simulation (an early sketch here: The scene one worked all the time, the scene two worked sometimes, but mostly would not, cutting out entire video output. The latter would only happen when using TripleHead2Go. However, in the case of the projector connected directly to MBP, everything worked well.

    My theory is that somehow the much demanding simulation in scene 2 overloaded the GPU, which was losing its ability to fire up the TripleHead2Go. Something to have in mind while contemplating hardware configurations involving TripleHeads.

    In my syphon Isadora scene I am taking the syphon image, convert it into "video" in the ImageToVideo actor, and then feed it into 3dQuadDistort. This means that GPU is taxed three times: first, when my custom app puts data into its pipeline, second, when Isadora copies image data from GPU to CPU, third, when Isadora renders it in the quad distort actor. That is in this setup the image data goes through the following route: CPU -> GPU -> CPU -> GPU. I imagine, that if there was a Core Image based 3d Quad Distort actor, there would be no need to convert Image to Video (this in itself requires copying image data from GPU into CPU –– extremely slow, above all), and the image data would stay on the GPU all the time. A motivation for further improvement of Isadora.

    NB: I used TripleHead2Go Digital Edition connected to MBP's display port through DP->DVI adapter. The outputs of the TripleHead2Go were connected to VGA inputs of the projectors through DVI->VGA adapters (not an ideal setup, I know).


  • I have the DP( thunderbolt) based matrox triplehead2go with three projectors.  I want to run three stages with different video on the three projectors connected to the triplehead unit.

    Currently I have the laptop as my main display and so assigned none of the three stages to the main display.  I have the three projectors actors assigned to stage 1 thru 3 respectively. My izzy preferences are stage 1 and left 1/3 , stage 2 as mid third, and stage 3 as right third. They split on the displays but are sent mirrored as  the same to all three projectors.  How do I split the signal to correspond with the three projector outputs of the trip2go unit?  I want the left 1/3 on projector 1 and so on.  What should I do in preferences or is there an actor to add to my patch which will make a clean cut of the data for each stage?

    a newbie.....

  • HEY I got it.  The matrox set up did not work the first time. Restart and presto. Three separate images to three different projects from the matrox.