math: sline lope [Archive] - C Board
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Nor
09-30-2003, 02:13 PM
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
JaWiB
09-30-2003, 06:56 PM
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...
revelation437
09-30-2003, 09:59 PM
y2-y1/x2-x1
thats the slope formula
Thantos
09-30-2003, 10:05 PM
y2-y1/x2-x1
(y2 - y1) / (x2 - x1)
is more accurate. Remember the order of operations :)
revelation437
10-01-2003, 01:40 PM
....
frenchfry164
10-01-2003, 05:13 PM
∆Y
----
∆X
Nor
10-01-2003, 08:38 PM
what is ∆ ?
XSquared
10-01-2003, 08:49 PM
∆ means delta. Delta means difference. Therefore, ∆y means difference in y.
Nor
10-01-2003, 09:01 PM
anyone know where i can squeeze 'z' into this equation?
googles doesnt have much on the subject

http://www.univie.ac.at/future.media/moe/galerie/geom1/geom1.html
is the only place that has what i want but they dont show the math
Sayeh
10-02-2003, 02:55 PM
If you're working in 3D, you need to be using a plane equation, not just slope intercept.
Silvercord
10-08-2003, 06:19 PM
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.