Re: [css-shaders] subdivision for transparency

Hello,

Responding to Robert and to the whole thread again.

As Dean and Robert explained, the proposal is that the result of a
custom() filter (including vertex and/or fragment shaders) is a 2D surface
that is then subject to further filtering by a new filter node or fed to
the transform/compositing step. This is the only model we could come up
with that integrates with other filter effects and transforms. We actually
tried another model, where the transform was passed to the shaders, but
that created other problems (e.g., it did not work well with multiple
filter nodes with multiple vertex shaders).

Cheers,
Vincent



From:  Robert O'Callahan <robert@ocallahan.org>
Reply-To:  "robert@ocallahan.org" <robert@ocallahan.org>
Date:  Tue, 4 Oct 2011 19:54:38 -0700
To:  "Gregg Tavares (wrk)" <gman@google.com>
Cc:  Dean Jackson <dino@apple.com>, James Robinson <jamesr@google.com>,
www-style list <www-style@w3.org>
Subject:  Re: [css-shaders] subdivision for transparency


>On Wed, Oct 5, 2011 at 12:05 PM, Gregg Tavares (wrk) <gman@google.com>
>wrote:
>
>On Tue, Oct 4, 2011 at 3:35 PM, Robert O'Callahan <robert@ocallahan.org>
>wrote:
>
>On Wed, Oct 5, 2011 at 9:13 AM, Dean Jackson <dino@apple.com> wrote:
>
>
>
>
>As for filters, I was really hoping that we'd be able to specify them as
>purely a 2d effect - as in whatever is composited in the end is a quad,
>not a mesh, even if the filter itself uses a mesh.
>
>
>
>
>I totally agree. The result of a "custom" filter primitive is flattened
>to an image. Nothing else makes sense, even within a filter chain
>
>
>
>
>
>That's fine in all you want to achieve is filtering effects but that
>doesn't fit with the examples shown by Adobe. They're morphing the
>content in 3d. 
>http://www.adobe.com/devnet/html5/articles/css-shaders.html#1
>
>In one case they're morphing something to look like a newspaper. It
>unfolds but is still interactive once it unfolds.
>
>In another case they're morphing a twitter feed a kind of wavy shape and
>they are interacting with it while it's in this wavy shape. I don't see
>why the user would think it's not 100% interactive.
>
>So it seems like for this proposal to be generally useful that content
>needs to able to be interactive (ie, the user needs to able to click on
>stuff just like they can with 3d css). Otherwise the number of use cases
>for it seems exceedingly small.
>
>
>
>
>Sure, and I just wrote a message about this on Vincent's original thread,
>but it's an orthogonal issue to the treatment of z-values. We can have
>filters affect the processing of events without requiring vertex-shader z
>values propagate through the rendering pipeline.
>
>Rob
>
>-- 
>"If we claim to be without sin, we deceive ourselves and the truth is not
>in us. If we confess our sins, he is faithful and just and will forgive
>us our sins and purify us from all unrighteousness. If we claim we have
>not sinned, we make him out to be a liar and his word is not in us." [1
>John 1:8-10]

Received on Wednesday, 5 October 2011 19:39:05 UTC