Public Group

# Quaternions concatenation is the sum of angles ? (2)

This topic is 2244 days old which is more than the 365 day threshold we allow for new replies. Please post a new topic.

## Recommended Posts

Hello,

With the two quaterions q1=q2=(cos theta/2, sin theta/2, 0, 0)
Does the product q1q2 yield a third quaternion q3 equals (cos theta, sin theta, 0, 0) ?

This is the result I am expecting to have from my quaternion class, but I don't have it.
My expectation is based on the fact that the concatenation of q1 and q2 will yield a quaternion representing both rotations. That means, for me, the sum of the angles each quaternion represents if the rotations are around the same vector.

So, does the product q1q2 yield a third quaternion q3 equal (cos theta, sin theta, 0, 0) ?
Or is there anything wrong with my assumption ?

##### Share on other sites
In mathematical world - yes.
In programming world - not necessarily, because of floating point rounding errors.

Indeed; closing.

##### Share on other sites

This topic is 2244 days old which is more than the 365 day threshold we allow for new replies. Please post a new topic.

This topic is now closed to further replies.

• ### What is your GameDev Story?

In 2019 we are celebrating 20 years of GameDev.net! Share your GameDev Story with us.

• 28
• 16
• 10
• 10
• 11
• ### Forum Statistics

• Total Topics
634111
• Total Posts
3015560
×