3D cartesian coordinate system conversion

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Sep 18, 2011
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Hi all,

I have a 3d point in a Cartesian coordinate system "A" that I want to map to Cartesian coordinate system "B". Both systems have the same origin, but coordinate system B has been rotated around all three axes (in respect to system A).

As a very simple example, lets say I know a point in system "A" is at (3,0,0) and system "B" has been rotated around one of the axes by 180 degrees. What I would like to do is identify a formula that would tell me "in coordinate system B, this point is at (-3, 0, 0)."

I have thought about this problem in 2d and know I can solve it using the magnitude of the vector v (origin to point) and known rotation angle phi:
newx = cos(phi)*v
newy = sin(phi)*v

I haven't figured out how to do this in 3d coordinates yet. I would appreciate it if someone could point me in the right direction on how to accomplish this! :)
 
Hi all,

I have a 3d point in a Cartesian coordinate system "A" that I want to map to Cartesian coordinate system "B". Both systems have the same origin, but coordinate system B has been rotated around all three axes (in respect to system A).

As a very simple example, lets say I know a point in system "A" is at (3,0,0) and system "B" has been rotated around one of the axes by 180 degrees. What I would like to do is identify a formula that would tell me "in coordinate system B, this point is at (-3, 0, 0)."

I have thought about this problem in 2d and know I can solve it using the magnitude of the vector v (origin to point) and known rotation angle phi:
newx = cos(phi)*v
newy = sin(phi)*v

I haven't figured out how to do this in 3d coordinates yet. I would appreciate it if someone could point me in the right direction on how to accomplish this! :)

For a quick tutorial - go to:

http://mathworld.wolfram.com/RotationMatrix.html

Finally, make google your friend .....
 
Thank you. Google is great, but if you don't know what terms to look for it can be awfully frustrating to find what you are looking for.

I actually skimmed over rotation matrices, but thought they were only useful for rotating a point vs. re-mapping them which is what I am trying to do.
 
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