creating curves with control-points


    Sep 06 2007 | 11:33 pm
    Hi forum!
    I am quite curious, if there would be an object in Max/Jitter to create curves with control-points.
    In fact I was searching already a long time, but didn't get, what I wanted. My goal would be to define as many control-points is I need. Then the "object" should create a curve between these points. For example: I define a start point (x,y or maybe also z), then the next point, and another, and so on...
    What I already found:
    --> cubiccurve-example.pat (jitter-examples/java):
    a great thing, but only 4 control-points. I am not well trained in Java on "mxj" :( , so I am not able to add some more control-points... and also antialiasing doesn't work here, don't know why...
    --> js_jitterspline-example.pat (jitter-examples/render):
    this would be THE thing I need! I can create as many control-points as I need. Unfortunately, all points in this example are created by "random". Again the problem with my not existing knowledge in JavaScript :((
    --> bspline (taken from the externals on http://www.jasch.ch):
    this is a very interesting object, but I don't understand, how to put some more control-points into it! I got an example from the forum under: http://www.cycling74.com/forums/index.php?t=msg&goto=113922&rid=5269&S=668f46a5697fcc4a9418021c8f9cd257&srch=curves#msg_113922
    but I want to define the points with "Number-Boxes" and not with a "Function". The other problem here is, that the curves are drawn into a LCD-object, so rendering doesn't work, I think...
    It would be great, if somebody knows an object in Max/Jitter, which can create such curves with control-points without Java or JavaScript. Maybe the "bspline-object" is what I need, but I didn't solve my problems to put some more points to the curve and the rendering into a "jit.window" with the help-file!
    I hope that somebody could give me a useful hint or idea how to solve my "curve-problem"!!!
    Thanks already,
    Johannes

    • Sep 07 2007 | 4:39 pm
      Hello there!
      I also posted this reply in the MAX/MSP-Forum under the Theme "max lacks a curve drawing tool with an intuitive GUI?!?", because the subject is also curve-drawing...
      Well, I spent quite a time on the "bspline"-object and finally I come forward but "step-bystep" (in fact, very small steps ;) ).
      I could reach to mix the two patches together now! Well, nearly...
      The bspline is rendered now in a "jit.window", and I can also put more control-points into the curve, by changing the "jit.matrix". I cannot just jet give the control-points the x/y-coordinates, but I will work on it (I think the solution is in creating a control-matrix, or so...).
      But here the problem for the moment: I can't visualize the control-points in the "jit.window"! The control-lines between the points are visible, but not the points. I have already a smoking head because of this problem...
      Here my patch:
      Can somebody help me here, please? Maybe for better understanding: in the "bspline.help"-file the points are visible, but just in an LCD-object!
      Thx a lot,
      Johannes
    • Sep 09 2007 | 9:15 pm
      Well like I said: "step-by-step" I caome forward...
      Here is the new patch:
      I can visualize ONE control-point now in the jit.window. But why only the last one? I wanted to see all 12 control-points in the window! I don't understand why, because the list sends the coordinates of all points but jit.gl.sketch only puts the last point out..
      Some ideas how to correct this bug?
      Thanks,
      Johannes
    • Sep 10 2007 | 3:45 pm
      Again me!
      Well, I really worked on a solution for that problem, but I don't come forward!!!!
      Is it really not possible, when I send a list of x/y-coordinates to jit.gl.sketch to draw a circle at every position in the list?
      I don't understand that...
      Just any news on this topic would be helpful!
      Thanks,
      Johannes
    • Sep 10 2007 | 4:18 pm
      Hi Johannes,
      Sorry, I haven't really been following this thread, but I might suggest
      that you check the Jitter Recipes for some of the answers, if you
      haven't already.
      Pay special attention to ElapseGraph and TwineBall. Let us know what
      you come up with.
      Best,
      Andrew B.
    • Sep 10 2007 | 4:30 pm
      its difficult to tell what could be going wrong, the patch is quite layered which makes it time consuming to follow your programming. its a shot in the dark, but i suspect they might be getting erased before they are drawn...
      perhaps you could simplify the patch.
      j
    • Sep 10 2007 | 6:21 pm
      I don't have time to figure out why this is nescessary, but adding a bang in
      your message in side of your draw_control_2 patcher makes it work
      (position $1 $2, circle 0.02, bang)
      On 9/10/07 9:30 AM, "justin" wrote:
      >
      > its difficult to tell what could be going wrong, the patch is quite layered
      > which makes it time consuming to follow your programming. its a shot in the
      > dark, but i suspect they might be getting erased before they are drawn...
      >
      > perhaps you could simplify the patch.
      >
      > j
    • Sep 11 2007 | 1:08 pm
    • Sep 11 2007 | 2:02 pm
      Bonsoir!
      Ok, here the patch a little bit "sweeped-out"...
      Thanks again for your help!
      I will go on changing the patch now. The goal is to create the curve with coordinates given by a webcam... We will see, if it works! I will go on posting!!
      Wish you all the best and till later!!! ;)
      Johannes