# rotating a quarterion

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hey. i know theres a lot of notes on this on google but honestly i dnt understand half of it. i just want to formula. for instance if i have a quarterion representing a direction in 3D space and i want to adjust that direction by 30 degrees around the Y axiz how wil i do it? thnx

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post-multiply it by a quaternion representing that rotation

-me

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sorry im new to this..

how do i multiply 2 quaternions?

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http://www.gamasutra.com/features/19980703/quaternions_01.htm

Sections of interest:
Table 1. Basic operations using quaternions.

Then also google "quaternion from axis angle". And remember that in programming always assume radians, not degrees.

Also important to note and only subtly mentioned in that article is that quaternion multiplication is order dependent. A * B does not equal B * A

-me

thnx that helps

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Sure. And just as an expectation setting I believe this took me about a week or so of constant effort to get working when I wrote my quaternion class ~5 years ago. It's kind of a big PITA to get a solid enough grasp of the math to implement things correctly if you are unfamiliar with it.

-me

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