Difference between revisions of "Talk:Quaternion"

Revision as of 04:18, 8 December 2007

In LSL, quaternion multiplication is written down in reverse order as in maths :

  Q2 * Q1   (LSL)

is the same as

  Q1 . Q2    (maths)

Perharps that would deserve a word of explanation here.

-- Catherine Pfeffer, 2007-12-08

This text has two shemas at the end. If you look well at it, the 90° rotation in the first schema and in the second schema are supposed to be opposite (once in z direction, the other time in -z direction) but the pink arrow materializing the rotation is the same.

It's the first schema that is correct (LSL follows right-hand rule for direction of positive rotations)

-- Catherine Pfeffer, 2007-12-07

That is correct, LSL uses right-hand rule set.

@@ Line 1: / Line 1: @@
-This text says that you rotate a vector Q by a rotation z with the formula :
+In LSL, quaternion multiplication is written down in reverse order as in maths :
+   Q2 * Q1   (LSL)
+is the same as
+   Q1 . Q2    (maths)
-     Q' = zQz<sup>-1</sup>
+Perharps that would deserve a word of explanation here.
-but LSL proceeds in reverse order when it rotates a vector by a rotation (* operator) :
+-- Catherine Pfeffer, 2007-12-08
-    Q' = z<sup>-1</sup>Qz
-Just give a try if you don't believe me... ;-). The reason is LSL follows the right-hand rule
-for direction of positive rotations.
-This has consequences over the rest of computations.
--- Catherine Pfeffer, 2007-12-06

Difference between revisions of "Talk:Quaternion"

Revision as of 04:18, 8 December 2007

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