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Timing issues



  • In the latest show I have mapped a large screen (12 by 10 meters), which was making large moves over the stage (back stage to front stage, vertical to horizontal positions), and ran into timing issues. The initial state of the screen was mapped using the IzzyMap, its points were published, and were then driven between the states using envelope generators, programmed with the same time intervals as the screen haulers. Here we ran into problems that during screen transitions between the positions, sometimes we'd get a perfect mapping, sometimes we had considerable¬†discrepancies. Under pre-premier pressure I had no time to pinpoint the exact reason, however, I noticed that the scene FPS was about 15 and sometime drop to below 10, due to heavy image processing Isadora had to apply to the movie in that scene. After I removed all of the filters to make sure that the scene FPS was a stable 30, it seemed that the mapping transition problem had gone away. However, I did not have time to confirm that for sure (the transitions could take between 10 and 30 minutes --- and one test would take most of the day's tech time). We had two shows so far and the problem did not surface, but I am still wondering, if the timing in the envelope generator was dependent on the scene frame rate (I'd say that would be the case, if the envelope generators were running in the same thread as a movie player and opengl draw calls).
    The comments about this issue would be appreciated.
    Thanks.
    --8
    Isadora 2.0.0b12
    MacOSX 10.9.5
    MacbookPro SSD and 16GB RAM

  • Tech Staff

    @eight

    As far as I know, yes the timing is dependent on the framerate, I think this should not be, because 1 second should always be 1 second. Can you file a feature request (http://troikatronix.com/support/isadora/) that the envelope generators or pulse generator use their own thread?

    Best
    Michel



  • @Michel Submitted a FR.

    --8