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Thread: texture color look up. Please help!

  1. #1
    Junior Member Newbie
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    Mar 2005
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    12

    texture color look up. Please help!

    Hello everyone,
    I am working on a 3D volume rendering application. My input volume data is a one byte MRI. I use 3D textures to display the volume. Now I want to color the voxels, along with alpha value, based on the input intensity value. So I tried using color look up table(glColorTable). Since the size of texture memory on my computer is low and data is huge I want to keep my data in the original 8 byte GL_LUMINANCE format however before actually displaying it on the frame buffer I want to color it with the look up table color.
    I am using VC++ 6.0. I use a library called GLIW to pull up the glColorTable extension which is a part of ARB_imaging extension. However the color table is not doing anything :-(. I create the color table as follows
    glColorTable(GL_COLOR_TABLE, GL_RGBA, 256,GL_RGBA, GL_UNSIGNED_BYTE, lut);
    where lut is defined as GLubyte lut[256][4];

    Could someone please help me?.

    Thanks.

    Abhijit

  2. #2
    Advanced Member Frequent Contributor
    Join Date
    Jan 2003
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    Virginia
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    586

    Re: texture color look up. Please help!

    Did you enable it with glEnable( GL_COLOR_TABLE )?

  3. #3
    Junior Member Newbie
    Join Date
    Mar 2005
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    12

    Re: texture color look up. Please help!

    Yes I did enable the color table using glEnable.

  4. #4
    Intern Newbie
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    Mar 2005
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    41

    Re: texture color look up. Please help!

    I am working in a much similiar project here.. But I am not using any libraries. I think the most appropriate solution for this is to attach a 1D ARB texture with the 3D texture, and use a shader to color your volume. I used it and is working fine. But I am having a problem with blending, maybe you wouldn't have it. I can send you a sample application if you want.

  5. #5
    Junior Member Newbie
    Join Date
    Mar 2005
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    Re: texture color look up. Please help!

    Thanks Tommy. I would definately like to take a look at your code.

    Abhijit

  6. #6
    Intern Newbie
    Join Date
    Mar 2005
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    41

    Re: texture color look up. Please help!

    HI,

    I tried to send you the sample application but your mail server refused the attachment.. It gave me the following error

    <alothe@gmail.com>:
    64.233.171.114 failed after I sent the message.
    Remote host said: 552 5.7.0 Illegal Attachment

  7. #7
    Junior Member Newbie
    Join Date
    Mar 2005
    Posts
    12

    Re: texture color look up. Please help!

    Hi Tomy,
    Did your application had any executable file? since google rejects incoming and outgoing messages with executables ( at least i am sure about outgoing).
    please try my other email address: ablothe@hotmail.com

    Thanks
    abhijit

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