Spatial Favicons : 12th Nov Call Notes & Action Items.

Hello,

These are the notes from our discussion:

1. General consensus on what 'sizes' attribute should mean hasn't been
reached.
*Physical size is not enough to be an appropriate proxy for level of
detail.*

2. Are 'sizes' as used in proposal imply real world size ?  Yes.

3. Two ways to look at sizes: Size vs Size at Distance. Need to be specific
about this and provide guidance.  Can the Level Of Detail increase when the
asset is closer, or depending on how many degrees asset occupies in the
current viewport ? What is the expectation ? - Kip & Nick had this concern.*
Kip *to open an issue.

4. When we have multiple spatial icons, what is the selection algorithm ?
 This is what spec says:
https://html.spec.whatwg.org/multipage/links.html#rel-icon

"If multiple icons are provided, the user agent must select the most
appropriate icon according to the type, media, and sizes attributes. If
there are multiple equally appropriate icons, user agents must use the last
one declared in tree order at the time that the user agent collected the
list of icons. If the user agent tries to use an icon but that icon is
determined, upon closer examination, to in fact be inappropriate (e.g.
because it uses an unsupported format), then the user agent must try the
next-most-appropriate icon as determined by the attributes"

5. Would spatial icons only allow fully opaque pixels or will various
levels of transparency be allowed. Rendering transparent pixels is
seemingly hard. - Question from Kip
Ravi>> I am increasingly thinking for the first pass, *we should just have
completely opaque. *

6. Vertex shaders can modify the bounding box. Did we consider that ?
Ravi >> Nope, we are specifically looking to keep the asset to be static.
Not just vertex shaders, glTF also has Morph Targets and Animations, all of
which can transform/translate vertices.

7. Regarding file size restrictions: Leonard suggested we be careful as
file size != size of asset on gpu. Also check KTX 2 compression.
Ravi>> Ack this. Will review.

Question:
- > Are we open to introduce new attribute ? Because re-using 'sizes' to be
a quality representative seems to be difficult to get by HTML spec. And
'bounding box' doesn't have a consensus. (And I agree, it is not a good
proxy).

regards,
Ravi