individual white subtraction


    Mar 15 2006 | 1:45 am
    hello
    I am trying to subtract the white color of drawings to be able to blend them, but I am confused. Is it possible to attribute that to each individual one, without having to fade one with another one? I mean, I want to do that individually to each one, maintaining the rest of the colors. I am trying to do that with the video plane, but that blends the whole image. (As far as I know... I am a total Jitter beginner) and all the others objects such as the alpha blend, etc, rely on a second image or jitqt movie to do that.
    any ideas of the object (s) that might feet in here?
    Thanks, Daniela

    • Mar 15 2006 | 2:05 am
      Use jit.chromakey with a target color of white (and probblay a small tolerance and xfade amount) to generate an alpha channel for your movie. If you're not familiar with chromakeying or alpha channels, I'd suggest researching online and running through the Jitter tutorials on the subject.
      If you like you could use the chromakey shader on the GPU to this end.
      -Joshua
    • Mar 16 2006 | 5:23 pm
      Hello Joshua Thanks for your respond. but I think that I am not making myself clear� and because I am total beginner, and it takes me a long them to understand the shader, video planes.. etc,... I want to make sure that I am in the right direction �.
      I have a red outline on a white background� so in that case there is no a problem because it is just one image. But when I another image is read, for example.. it appears on top of that image, let's say a blue outline on a white background� that image is covering the first one.
      I want the colors to merge, meaning, I want to see outlines, the blue and the red �one on top of the other�. With no white colors interfering� (Just the matrix background)
      So what I aiming for and because of the way each sub patch of my image works, I would like to load the image to read only the outline, forgetting about the image's white background�
      The alpha channel and the chromakey is great, but it requires of a second image inside the subpatch to blend it with�
      I am sorry if I am not making sense, �I do not know how else to explain this� Thanks Daniela
    • Mar 16 2006 | 5:51 pm
      This can be handled by using mode 2 of jit.chromakey to generate an alpha channel for blending.
      - Andrew B.
    • Mar 16 2006 | 8:27 pm
    • Mar 20 2006 | 10:33 pm
      Hello I still cannot do it.... I do not get it... I tried without the gl.render and it works only using the example pat... but when I apply it to my patch it does not work.. So I finally decided to use the gl.render stuff and I changed my matrix to a float 32. I get how to send the gl.render to the matrix... but it still does not work!!.. Maybe I am having problems with the color values now that I am working with gl render... If you tell me what to read I will...
      Here is the sub patch and also I attached the example patch that I was basing my work from. . Because maybe I do not need the gl render stuff? knowing that I could have much more visual effects using the different video planes? but for then moment I just want to see my outlines images without the white!
      here is the individual sup patch and In attached images.. after is the example patch thanks, Daniela
      example patch
    • Mar 20 2006 | 10:52 pm
      Hi Daniela,
      Several things you are doing improperly here. It seems like you need to spend a little bit more time learning the fundamentals before approaching this task.
      1. I'm not sure why you have the matrix output of jit.chromakey connected to jit.gl.render. This is converting the image to geometry (and improperly so if that is what you would be trying to achieve). Also your arguments to "jit.matrix big_composite float 32 @usedstdim 1" do not make sense. they should be . You have an incorrect type (must be float32 *no space*), and no dimensions.
      2. you don't have proper spaces in your jit.gl.videoplane arguments. this is *important*. "jit.gl.videoplane Stamping @blend_enable 1@depth_disabled @matrixoutput1" should be "jit.gl.videoplane Stamping @blend_enable 1 @depth_enable 0" (note that there must be a space between the 1 and the @ symbol, depth_diabled is not an attribute, and you shouldn't be using matrix output for this putpose)
      Hope this helps. Please take some time to walk through the tutorials carefully. I think you'll find this easier once you have done so.
      -Joshua
    • Mar 21 2006 | 2:51 pm
      Hi Joshua Thanks. It did help. And also looking at all the render examples patches have been a revelation to me! I think that know that things are starting to be in place the blending etc should become an easier task... Daniela
    • Mar 28 2006 | 12:09 am
      Hello
      I have a couple of questions
      I do not understand if you can send send render message from my 6 sub patches to one jit.slab to read the chromakey shader and then to one video plane stamping to render the whole movie. Because I still cannot achieve any blending to work and if I do not have the blending I cannot do any effects because I do not see how the images blends..? I want to make an organize patch? and be economical?. But it is not working?
      Or should I treat each subpatch individually and have 6 simultaneous rendered video planes?
      Also is this correct? I do not get any error message? and it does not work..