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Re: [SVG Transforms 1.0] - Feedback

From: Anthony Grasso <anthony.grasso@cisra.canon.com.au>
Date: Mon, 23 Mar 2009 16:50:41 +1100
Message-ID: <49C72331.7090300@cisra.canon.com.au>
To: "G. Wade Johnson" <gwadej@anomaly.org>
CC: www-svg@w3.org
Hi G. Wade,

Thank you for your comments on the SVG Transforms specification. The feedback 
has been placed in our public tracker[1][2] and the SVG Working Group will 
discuss the comments in the next few telephone conferences.

Kind Regards,

Anthony Grasso

[1] http://www.w3.org/Graphics/SVG/WG/track/issues/2250
[2] http://www.w3.org/Graphics/SVG/WG/track/issues/2251

G. Wade Johnson wrote:
> Some quick feedback.
> 
> 1. In section 3. TransformList Extensions, under scale(<sx> [<sy>
> [<sz>]])
> 
> This states "If <sy> and <sz>  are not provided, it is assumed to be
> equal to <sx>." What is the value of <sz> if <sx> and <sy> are
> provided? If all objects are actually 2D, does scaling have any effect
> beyond the translation effect due to the Z coordinate scaling?
> 
> 2. In section 3. TransformList Extensions, under
>    rotate(<rotate-angle> <nx> <ny> <nz> [<cx> <cy> <cz>])
> 
> An example showing what new construct would be equivalent to the old
> rotate might help. (Other than rotateZ( <angle> [<cx> <cy>] )) I guess
> I just don't understand the parameters <nx> <ny> <nz>.
> 
> 3. In section 5. Converting a 4x4 to a 3x3 matrix, paragraph 5, "the
> eqation is derived" should be "the equation is derived"
> 
> 4. General conceptual feedback
> 
> I see that the viewing plane is defined as z=0, but I don't see any
> mention of whether z increases toward the viewer or away from the
> viewer.
> 
> Personally, I see increasing z as getting farther from me, but I could
> also argue that larger z should be in front of smaller z. Obviously,
> this needs to be specified.
> 
> 5. General conceptual feedback
> 
> What is the visual effect of objects that are in front of the viewing
> plane? Are they "behind us" or in front of everything?
> 
> -------
> Despite these items, this looks really good to me. (I really want
> transform-origin right now.<grin/>)
> 
> G. Wade
Received on Monday, 23 March 2009 05:51:23 GMT

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