[x3d-public] Fw: ProtoInstance USE without name

[Don Brutzman]

(emails crossing)

On 11/29/2020 12:17 PM, Andreas Plesch wrote:
> 
> Thanks, Don.
> 
> Yes, the tooltip is helpful. However, the tooltip does not say that the name should ( or must? ) be omitted if the ProtoInstance is USE, only that it can be omitted.

Similarly thanks Andreas.  I hope that the rapid response to improve tooltips and add a scene authoring hint helped... if beauty is best perceived in the eye of the beholder, you guys can certainly suggest further clarifications/improvements.

> The possibility of a mismatch of the type of node between DEF and USE exists for all nodes, and I thought is a feature of the design (additional validation) rather than a liability.

Yes indeed.  ProtoInstance can also elude type matching until late in the game, in the same way.

Feature or liability is again perhaps subjective but...  X3D validator (X3D Schematron), X3DUOM details and design of strongly typed APIs (X3DJSAIL, X3DPSAIL) are also designed to detect those problems.  So far they work on all relevant scenes in X3D example archives.

> I think the varying behaviour of browsers points to the need of additional spec. language. In particular, will support for case B ( USE but no name ) become a requirement ?

Trying to enforce an omission as a requirement for corresponding behavior can be a steep slippery slope... as shown in current discussion regarding field synonyms, elaborating why "Browser behavior is undefined" is a good stance for players.  For a ProtoInstance USE containing a name, offering a warning is likely polite/sufficient before continuing onwards to running the scene.

Specification critiques and potential improvements are always welcome... good warmup for an imminent ballot period as well!  8)

Meanwhile I've gotta get back to X3D4, good luck with these continuing efforts.

> -Andreas
> 
> On Sun, Nov 29, 2020 at 2:05 PM Don Brutzman <brutzman at nps.edu <mailto:brutzman at nps.edu>> wrote:
> 
>     Sorry to miss the whole email party... hope you landed where we landed before.  There was a bunch of mail about this, perhaps a year ago, searchable in mail archives.
> [...]

all the best, Don
-- 
Don Brutzman  Naval Postgraduate School, Code USW/Br       brutzman at nps.edu
Watkins 270,  MOVES Institute, Monterey CA 93943-5000 USA   +1.831.656.2149
X3D graphics, virtual worlds, navy robotics http://faculty.nps.edu/brutzman