Re: [css-transforms] CSS3D breaks with opacity flattening

On 22/09/16 11:37 PM, Rik Cabanier wrote:
>
> In addition, your proposal *also* affects web content because opacity 
> is now applied to the group instead of being distributed to the children.
It's true, but I figured it would be close enough to the old rendering 
that the majority of existing content would work with it (assuming they 
just want opacity, not specifically opacity distributed to the children) 
while also being correct wrt group-opacity and not implementation dependent.

>     This thread was started by an author who's content was broken, so
>     it seems reasonable to re-visit these assumptions.
>
> Yes, we went over his examples and told him how to fix it (= apply 
> opacity to the elements)
> Since Firefox knows that it's flattening, could it create a warning in 
> the console and point to an MDN page with more information?
>
> 1: 
> https://groups.google.com/a/chromium.org/forum/#!msg/blink-dev/eBIp90_il1o/jrxzMW_4BQAJ 
> <https://groups.google.com/a/chromium.org/forum/#%21msg/blink-dev/eBIp90_il1o/jrxzMW_4BQAJ>
> 2: https://bugzilla.mozilla.org/show_bug.cgi?id=1250718
> https://bugzilla.mozilla.org/show_bug.cgi?id=1278021
> https://bugzilla.mozilla.org/show_bug.cgi?id=1229317

I still think that applying group-opacity to a subset of a 3d scene is a 
reasonable use case (that can't be easily solved without this), and one 
that we could support without breaking anything worse than we already 
plan to.

Doesn't look like this is getting much traction though, so I'll probably 
just accept the spec change and go ahead with ship flattening of opacity 
in Firefox.

- Matt