Thread: math: sline lope

  1. #1
    ‡ †hë Ö†hÈr sîÐè ‡ Nor's Avatar
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    math: line slope

    i need to draw an imaginary line in a 3D world using the slope
    method. (terminology is off. been a few years since math class)

    if i remember right its the difference of x over the difference of y.
    (X1 - X2 ) / (y1 -y2) used to calculate any point on a straight line.

    in short im trying to find a way to use this in a 3d world for collision detection(GuNs – path of the bullets/projectiles).
    any links would be a big help.
    thx
    Last edited by Nor; 09-30-2003 at 08:18 PM.
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  2. #2
    carry on JaWiB's Avatar
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    if i remember right its the difference of x over the difference of y.
    (X1 - X2 ) / (y1 -y2) used to calculate any point on a straight line.
    its y's over x's

    (y2-y1)/(x2-x1)

    at least thats how ive been doing it on all my homework hehe...
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  3. #3
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    y2-y1/x2-x1
    thats the slope formula

  4. #4
    & the hat of GPL slaying Thantos's Avatar
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    y2-y1/x2-x1
    (y2 - y1) / (x2 - x1)
    is more accurate. Remember the order of operations

  5. #5
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    ....

  6. #6
    Code:
     ∆Y
    ----
     ∆X

  7. #7
    ‡ †hë Ö†hÈr sîÐè ‡ Nor's Avatar
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    what is ∆ ?
    Last edited by Nor; 10-01-2003 at 09:00 PM.
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  8. #8
    C++ Developer XSquared's Avatar
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    ∆ means delta. Delta means difference. Therefore, ∆y means difference in y.
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  9. #9
    ‡ †hë Ö†hÈr sîÐè ‡ Nor's Avatar
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    anyone know where i can squeeze 'z' into this equation?
    googles doesnt have much on the subject

    http://www.univie.ac.at/future.media...om1/geom1.html
    is the only place that has what i want but they dont show the math
    Last edited by Nor; 10-01-2003 at 09:07 PM.
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  10. #10
    Visionary Philosopher Sayeh's Avatar
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    If you're working in 3D, you need to be using a plane equation, not just slope intercept.
    It is not the spoon that bends, it is you who bends around the spoon.

  11. #11
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    so does an equivalent of 'slope' exist for 3d? I kind of thought it would be:
    deltaz/(deltay/deltax)

    but it seems pretty much useless anyway, if it exists.

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