- From: Alan Gresley <alan@css-class.com>
- Date: Sun, 27 Nov 2011 22:18:24 +1100
- To: Daniel Glazman <daniel.glazman@disruptive-innovations.com>
- CC: www-style@w3.org
On 26/11/2011 8:11 PM, Daniel Glazman wrote:
> Le 25/11/11 20:46, L. David Baron a écrit :
>
>> Does anything define what it means to be clockwise around an axis?
>> Clockwise and counterclockwise make sense in terms of a plane and an
>> observer on one side of that plane, but I don't know what they mean
>> in terms of an axis. Can we use the right-hand rule instead? Or
>> can we define that the relevant axis points from the plane to the
>> observer or vice-versa?
>
> The latter. Defining ckw rotation around an axis is trivial: place an
> observer on a plane orthogonal to that axis, looking towards positive
> axis values; then rotate the plan clockwise for the observer around the
> axis.
>
> </Daniel>
Both rotate() and rotateZ() are synonyms.
We have a box,
-------------
| |
| |
| Z |
| |
| |
-------------
which can be painted at any level in the z-index. Without any transforms
(rotation) on the X and and Y axises or transform-origin, the box will
turn clockwise on it axis (marked with the letter Z). This center axis
point is on a plane (represented here as a box) which has it's central
axis perpendicular to the plane of the observer.
--
Alan Gresley
http://css-3d.org/
http://css-class.com/
Received on Sunday, 27 November 2011 11:18:58 UTC