Re: [css-transitions] Proposal and RFC: spring() timing function

On Fri, Jul 1, 2016 at 3:14 PM, Dean Jackson <dino@apple.com> wrote:
>> On 2 Jul 2016, at 8:06 AM, Tab Atkins Jr. <jackalmage@gmail.com> wrote:
>> On Wed, Jun 29, 2016 at 9:32 PM, Dean Jackson <dino@apple.com> wrote:
>>> Secondly, we'd need to
>>> describe how this works for a keyframed animation, where the duration applies
>>> over all the keyframes.
>>
>> This, I think, is the part that needs the most thought.  This really
>> is a pretty big change from the current model, because it seems to be
>> impossible to accurately chain a spring effect into anything else
>> unless you run the math yourself to determine the effective duration.
>> That suggests pushing forward the timetable on "sequence/parallel
>> animation groups in WebAnim and CSS" might be worthwhile.
>
> Is it that important that spring() applies to keyframed animations
> from the beginning? Springs are an emulation of a physical effect, and
> it's rare that you'll combine that with a keyframe (which is an unnatural
> effect).
>
> Springs make more sense going between two points. e.g. transitions.
>
> I think we can address keyframes, but it isn't urgent. At worst we can
> leave it as is for now, which means that the keyframe would advance
> once its duration slice has expired. This could be while the animation
> is still springing, or well after it as settled.

I don't think it feels unusual to spring something into place, then
kick off some other animation when it arrives at the target spot.  You
can set up those types of things easily with keyframes and
duration-based timing functions.

~TJ

Received on Friday, 1 July 2016 22:57:01 UTC