W3C home > Mailing lists > Public > www-svg@w3.org > June 2015

Re: SVG animations without SMIL

From: Paul LeBeau <paul.lebeau@gmail.com>
Date: Thu, 4 Jun 2015 17:48:28 +1200
Message-ID: <CACfsppB9JLL1GrjwsPMgo4G4G2bLNV416yF=OLF53gtT-pggAA@mail.gmail.com>
To: Brian Birtles <bbirtles@mozilla.com>
Cc: Shane Stephens <shans@google.com>, www-svg <www-svg@w3.org>
Brian wrote:
> When you actually go to author content though, you very often need anchor
points or some way of describing *how* you want to go from A to B.


That's true, but I don't think that is something an SVG renderer should
need to worry about.

Expanding the rule to allow renderers to do simple segment conversion would
probably be enough.  The effect of "anchor points" or other controlled
tweening can be achieved either by being careful with how you define the
paths; or with the help of a tool to adjust either or both of the src and
dest paths.

Paul


On 4 June 2015 at 16:41, Brian Birtles <bbirtles@mozilla.com> wrote:

> On 2015/06/04 12:04, Shane Stephens wrote:
>
>>
>>
>> On Thu, Jun 4, 2015 at 11:18 AM Brian Birtles <bbirtles@mozilla.com
>> <mailto:bbirtles@mozilla.com>> wrote:
>>
>>     On 2015/06/04 3:20, Philip Rogers wrote:
>>      > For consistency with the other geometry attributes, I don't see
>> many
>>      > costs to promoting 'd' as a simple string presentation attribute.
>> The
>>      > proposal would be to have it work just like animating 'd' works
>>     today:
>>      > string -> string where the interpolation is done on the parsed
>>      > representation.
>>
>>     I'd prefer we don't do this. Apart from the obvious difficulties with
>>     SVG path syntax, the requirements for interpolating between two paths
>>     are so restrictive (same number and type of segments) as to make
>>     hand-authoring path animations almost impossible.
>>
>>
>> FWIW we could pretty trivially relax this requirement when interpolating
>> in CSS. There's no fundamental reason for forcing matching segments -
>> all segment types can be arbitrarily split and from memory there are
>> adequate representations of each pairwise conversion.
>>
>
> When you actually go to author content though, you very often need anchor
> points or some way of describing *how* you want to go from A to B. For
> example you often want to say, "This corner point here, it corresponds to
> that corner point in that path (despite the fact that the ratio of segments
> before and after is completely different)."
>
> Flash has shape hints for this and you can see the difference between the
> default tween and a hinted tween between the outline for M and N here.[1]
>
> [1] http://www.adobe.com/devnet/flash/learning_guide/animation/part12.html
>
> http://www.adobe.com/devnet/archive/flash/articles/concept_shape_hints.html
> also has another demo compared an unhinted morph from 5 to 3 with a hinted
> morph from L to Z
>
>
Received on Thursday, 4 June 2015 05:49:16 UTC

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