Changing Video Coordinates


    Apr 10 2012 | 5:41 am
    Okay, Im not sure if this is in the correct place so please correct me if I am wrong as I am knew to this. I do have some Max MSP knowledge but I am stumped.
    I am looking to take the silhouette of a person, the video of a silhouette anyway and move the movie through a space. I can't seem to figure out a way to move the video based on an x coordinate. I managed to do so with a picture but I need to control the video speed based on the change in x. and change the x coordinates of the video based on the x coordinate I give to the patch. Let me know if you need any more information as this is somewhat hard to explain. Any and all help would be amazing! Thanks in advance!

    • Apr 10 2012 | 5:58 am
      I am confused by your request. You seem to be asking two things:
      1. How to move part of a video (a silouette) around the window
      2. How to also change the rate of that video based on its x-coordinate.
      First, the easiest way to move videos about the window is to use jit.gl.videoplane.
      Second, the x-position (in this case a gl coordinate, not a pixel-position) can simply be scaled and fed into the rate of the jit.qt.movie, or you can be controling which frame is being shown using the frame $1 command to the jit.qt.movie.
    • Apr 10 2012 | 6:17 am
      Thanks for the quick response!
      Basically I have a looping video. The silhouette which is suposed to represent a shadow. In the pictures attached I managed to move just a still image through the space attached to the x coordinate. The x coordinate will be associated with a person moving through a given space and I am attaching my own shadow to their feet. So when the person stops. or the X coordinate stops I want the video to stop. But when the person is moving I want the video to be playing or looping.
      1. How to move part of a video (a silhouette) around the window
      somewhat. It is only the silhouette in the movie. so If I can find a way to move the entire movie move that would work.
      2. How to also change the rate of that video based on its x-coordinate.
      Yes the faster the x-coordinate is changing the faster the movie is playing. And if the x coordinate is not moving or stopped the video will loop slowly or stop.
      Thanks again! I will look into jit.gl.videoplane and see if this helps!
      [attachment=190657,3679] [attachment=190657,3680]
    • Apr 10 2012 | 7:09 am
      Ok the Jit.gl.videoplane seems to be working perfectly. The only question I still have is if there is any way that I can make the change in x change the framerate on a video. Basically if the x coordinate is 15 in one frame and 13 in the next compared to 15 in one fram and 8 in the next. The one with the change of 7 will make the movie loop faster than the change of 2 where it should go slower. Thanks again!
    • Apr 10 2012 | 4:10 pm
      You want to scale your rate of change in X to your video's playback rate. If you are dealing with isolated changes in X, this patcher will work for you:
      If, however, you have a stream of X values and you need to calculate their rate of change, you need a different strategy.
    • Apr 10 2012 | 10:54 pm
      Ya I will be streaming the coordinates in from a program pulling the x coordinates from a kinect.
    • Apr 11 2012 | 12:47 am
      Aha. Here are two suggestions:
      For the silouette, take a look at the last patch on this page:
      http://cycling74.com/forums/topic.php?id=38963
      Use [pak position 0. 0. 0.] to position the mesh in the window.
      For the speed of the video, try a variation of this: