Updated submission info

[javagl]

The SubmittingModels.md may have to be reviewed.

Things that are fixed in the current state of this PR:

• Removed an inlined image that does not exist
• Fix broken link to #converters. Minor rewording of the variants. Added requirement that models pass validation (!)
• Started updating the description of the metadata.json

Here, I stumbled: The description of the JSON there is a bit incomplete, and I'm not sure how to complete this:

• What is version: 2? (I wondered whether this referred to glTF itself...).
• Which are valid tags? (Yeah, 🐘 -> 🏠 )
• Suggestions:
  • name: The name of the subdirectory that the model is contained in
  • path: The path of the model subdirectory, relative to the repository root
  • screenshot: The path to the screenshot, relative to the model subdirectory
  • summary: A short description of what the model is or demonstrates
  • createReadme: Should always be true

The legal part also does not seem to list everything that can be found in the actual JSON files. One example is

            "license": "CC-BY 4.0",
            "licenseUrl": "https://creativecommons.org/licenses/by/4.0/legalcode",
            "artist": "Cesium",
            "year": "2017",
            "owner": "Cesium",
            "what": "Everything",
            "text": "CC BY 4.0 International",
            "spdx": "CC-BY-4.0",
            "icon": "https://licensebuttons.net/l/by/3.0/88x31.png"

That looks like a lot of redundant redundancy, which is pretty redundant.

• What is the difference between license and spdx? If license is only intended for non-spdx licenses, then I wonder whether this could be merged into license, with the values either being one of the spdx-identifiers, or "Custom".
• Is text really only for the link text, and does it make a difference of whether the link text is CC-BY 4.0 or CC-BY 4.0 International ?
• That icon link... hm. Is this necessary and useful? Even if the answer is 'yes': Is "hotlinking" to a random PNG file the right thing to do here...?
• There should be details about the artist/owner. For example, at least I guess: "The names of artists, separated by comma,..."

And... most importantly: What exactly do submitters have to do here? Which of these fields are (or can be) auto-filled: I've seen that link to the CreateJson.html (which of course does not work on GitHub...), but is this supposed to fill out most of this information based on less input? Users shouldn't have to figure out the licenseUrl on their own, and it would be hard to make sure that the information in the given form is consistent ...

[DRx3D]

Answering some of the questions.

• This is version 2 of the metadata.json file. It has nothing to do with the version of glTF.
• Technically all tags are valid; however, only a few a recognized by the system when creating the category READMEs.
• The JSON contains a number of optional fields. These files are filled in when the during various options, such as building the license information (reuse). A lot of the items related to legal are optional from the user's standpoint.
  • license is the official name of the license. There are several variants of the CC license that map to the same legal license.
  • spdx is the reuse name of the license.
  • text is the standardized human-readable version. 'spdx' is almost always determined from 'text'. If a non-standard license is used, special considerations and handling need to be performed.
  • icon is really only used for CC licenses. It might need to be enforced.
  • These optional fields could be calculated every time; however, in early development I found it easier to include them in the metadata. The repo build program can automatically update the metadata.json file to include all optional fields.
• The CreateJson.html file creates a valid metadata.json file. The creator fills in fields and the populates and displays the JSON structure. That s/w is in beta ATM.

I am not going to claim everything is the correct way here. There is likely a better way to do this, and I am completely open to changing this.