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Thread: how can i read an RGBA value off a point on the surface of a polygon?

  1. #1
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    how can i read an RGBA value off a point on the surface of a polygon?

    I thought about using glreadpixels, but it only lets you read a rectangular region in two dimensional space. I need a method that will yield the RGBA value for any point on any surface of any polygon anywhere in 3d space.

    I'm stuck. Any help is much appreciated.

    -Ixstala

  2. #2
    Senior Member OpenGL Guru
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    Re: how can i read an RGBA value off a point on the surface of a polygon?

    You can project the point on the polygon to screen coordinates using gluProject. Then use glReadPixels with the coordinates you get from gluProject to get the RGBA-value.

  3. #3
    Senior Member Regular Contributor
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    Re: how can i read an RGBA value off a point on the surface of a polygon?

    do a search in the forum on picking...
    yes

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