Re: SVG animations without SMIL

On Jun 2, 2015, at 7:29 PM, Philip Rogers <pdr@google.com<mailto:pdr@google.com>> wrote:

www-svg,

Animating SVG content without SMIL can be difficult and I'd like kick off a discussion on how to improve it. This recently came up because IE does not have plans to support SMIL and Blink is moving towards removing support as well.

Two projects at Google switched from SMIL to CSS animations and an issue we hit was that useful graphics attributes such as 'd' are not yet presentation attributes. Only attributes promoted to presentation attributes can be animated with CSS. Would it be possible to have even more attributes become presentation attributes in SVG2? Making 'd' and 'transform' presentation attributes has been discussed before but seems to have petered out. For folks not familiar with CSS animations, I created a small demo showing how they work: http://philiprogers.com/smilandcss.html

The CSS Transforms spec is now responsible for defining transform. `transform` is indeed a presentation attribute today. And partly implemented that way in WebKit and Blink already.

For the `d` attribute there was a discussion about the property name. (d is not very descriptive.) There were also concerns about the semantic of such a property. Should the value be a string? Should the value be path functions as we have them for clip-path? E.g path(“M100,100….”), polygon(), inset(), circle()? And I think there were even concerns about animating the string.

Anyway, d as CSS property is not off of the table. Just not a priority for the SVG 2 specification.

Greetings,
Dirk


A second set of issues is the feature gap between web animations / css animations and SMIL. These are probably best addressed in www-syle but they are worth pointing out; Brian outlined a number of these in https://birtles.wordpress.com/2015/05/01/what-do-we-do-with-smil.