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Re: [SVG Transforms 1.0, Part 2: Language (2009-03-20)] - Feedback for "4. 'animateTransform' Extensions"

From: Gavin Kistner <gavin@phrogz.net>
Date: Mon, 23 Mar 2009 22:14:11 -0600
Cc: "Dr. Olaf Hoffmann" <Dr.O.Hoffmann@gmx.de>, www-svg@w3.org
Message-Id: <0AAB2604-6F8E-4A77-A3EA-B5E4BEC72AC6@phrogz.net>
To: Rick <graham.rick@gmail.com>
On Mar 23, 2009, at 8:50 PM, Rick wrote:
> 2009/3/22 Dr. Olaf Hoffmann <Dr.O.Hoffmann@gmx.de>:
>> Hello SVG WG,
>>
>> mainly a suggestion for this section:
>>
>> Consider the type matrix to be animatable too, this can
>
> My $0.02, I've noticed that doing transformations with matrices is
> noticeably more efficient than with lower level transforms, presumably
> because they are multiplied out to matrices anyway and that step is
> skipped.  I can't say that I've tested this everywhere, but this is
> the case in Firefox at least.
>
> Matrix animations would be nifty.

I had thought that piecewise interpolation of the elements in a  
transformation matrix will often result in intermediary matrices that  
are not desirable. Specifically, can't the piecewise animation of two  
affine matrices result in intermediary matrices that are not affine?

I'm not positive about this, but believe I've experienced it in the  
past. At least in the 4x4 matrices of 3D world, lerping two matrices  
is not the same as lerping the constituent individual scale/pivot/ 
translate/rotation vectors used to produce the end matrices.
Received on Tuesday, 24 March 2009 04:15:02 GMT

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