[x3d-public] Finding more than one use of a DEF in VRML - Chisel, duplicated DEF in proto

[Don Brutzman]

On 3/25/2020 7:11 PM, GPU Group wrote:
> Chisel? "it was simply put in the public domain by Trapezium when they folded many years ago. They didn¹t specify any license" - Louka
> http://dug9.users.sourceforge.net/web3d/temp/chisel-src.zip

Also

* X3D Resources: Conversions and Translation Tools
   https://www.web3d.org/x3d/content/examples/X3dResources.html#Conversions

* 15. Chisel VRML Optimisation Tool
   http://www2.hrp.no/vr/tools/chisel/install.htm

   with autoinstaller
   http://www2.hrp.no/vr/tools/chisel/install.htm

   and documentation
   http://www2.hrp.no/vr/tools/chisel/doc/index.html

   provided by Halden Virtual Reality Centre.
   http://www2.hrp.no/vr/about/index.html

   Originally built by Trapezium and maintained by NIST.
   http://ovrt.nist.gov/chisel.html
   (link no longer working, hoping to find replacement)

> But I suspect double-deffing isn't illegal. I think I've been through it, and different browsers honored the first or last definition.
> -Doug

Agreed.  Although it is legal in X3D abstract specification and in VRML/ClassicVRML encodings, it leads to validation difficulties in XML (and at some point JSON when JSON Schema is finished).

Wondering if we should define a suggested practice for de-duplicating DEF names within a proto, e.g.

	MyWhizzyProto includes DEF SomeDuplicatedName

might get tidied up to globally rename

	MyWhizzyProto includes DEF MyWhizzyProto.SomeDuplicatedName

We might also apply this in the PrototypeExpander work if that gets revisited.

Thoughts?

> On Wed, Mar 25, 2020 at 7:43 PM John Carlson <yottzumm at gmail.com <mailto:yottzumm at gmail.com>> wrote:
> 
>     That is, more than one DEF with the same value.
> 
>     I realize that separate PROTOs may have the same DEF due to namespaces. Unfortunately writing a Unix script to find this takes massive brain power.
> 
>     John
> 
>     On Wed, Mar 25, 2020 at 8:37 PM John Carlson <yottzumm at gmail.com <mailto:yottzumm at gmail.com>> wrote:
> 
>         I’m not particular looking for a vrml parser unless it catches double use of a DEF.

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