Topic: Y rotation matrix?
| Y rotation matrix?|
| Poster ||: LaughingJack|
| Posts||: 1|
| Country ||: United Kingdom|
| City||: Southampton|
|Posted by LaughingJack on 26/07/2007 at 05:30:28|
|If I understand correctly, the signs are wrong for your rotation about the Y axis. Shouldn't it be:|
cos 0 -sin
0 1 0
sin 0 cos
| Poster ||: oldmasterchu|
| Posts||: 1|
| Country ||: Hong Kong|
| City||: Hong Kong|
|Posted by oldmasterchu on 29/04/2010 at 14:48:43|
LaughingJack is right. So does the X and Z rotation matrics.
The calculation in the example shows the coordinate rotate 45 degree counter clockwise around Z axis, not the point (10,5,0).
If you rotate the point (10,5,0) 45 degree CCW around Z axis, the rotated point is still in the first quadrant of the XY plane. Its y-value can't be negative.
| Poster ||: Anonymous|
| Posts||: |
| Country ||: |
| City||: |
|Posted by Anonymous on 26/10/2011 at 15:48:23|
|You are both talking about CCW rotation. But there are 2 directions in which to rotate. |
is indeed for rotating CCW.
(As shown in the example) rotates CW, which, I believe, would place the the point in the 4th quadrant with a negative Y value.
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