feat: Add options to configure pruning unused vertex attributes

[hichemfantar]

The code changes introduce two new options to the CLI tool:

• --pruneKeepAttributes: Determines whether to keep unused vertex attributes, such as UVs without an assigned texture.
• --pruneKeepLeaves: Determines whether to keep empty leaf nodes.

These options provide more control over the pruning process, allowing users to optimize the resulting glTF files based on their specific requirements.

closes #278
closes #280

[donmccurdy]

Thanks @hichemfantar! I'm OK with these changes, though I think naming the options --keepattributes and --keepleaves might be more in line with the existing flags?

@drcmda any concerns here? Would we prefer that unused UVs be kept by default?

[hichemfantar]

@donmccurdy the new flags are opt in and shouldn't change the existing behavior. as far as naming goes, i just wanted to be explicit but feel free to change as you see fit.

I'm also considering adding flags for all the prune options. what do you think?

btw do you mind taking a look at #275 while i have your attention?

[donmccurdy]

With the naming, it's mainly consistency that I'm worried about:

--keepmeshes
--keepmaterials
--pruneKeepAttributes
--pruneKeepLeaves

The prune() transform is an implementation detail; to a reader "prune" and "keep" will sound contradictory.

I would advise against adding more flags than you're able to spend time testing — the effect of the full pipeline may give different results than the options of any one transform step would suggest. For example, leaf nodes skipped by prune() may nonetheless be removed by flatten(), or other optimizations.

... that said, I'm primarily the maintainer of glTF Transform, and not a frequent contributor on this repository, so I'm hoping others will chime in with preferences about the API and configurability. Personally, I usually pre-process directly with glTF Transform and then run gltfjsx without the --transform flag.

[hichemfantar]

I agree with the naming, i made the changes.
as for the other options, it's to make sure the user has a way to opt out of the default behavior which may not be desirable in all circumstances or even be problematic like it was in my case.

[hichemfantar]

@donmccurdy is there anything blocking this?

[donmccurdy]

@hichemfantar the --keepleaves flag does not work; the leaves have already been removed before prune() runs. That's not a trivial fix – please be careful of testing if you feel strongly about including that flag.

I'm not planning to merge new features into this repository myself — I am not the right person to approve and merge your PR, someone else will need to do that.

[hichemfantar]

@donmccurdy i reverted back my changes and now only the keepAttributes flag remains

[drcmda]

@donmccurdy no issues with that! but i'm a little out of the loop, do you think it's fine?

[donmccurdy]

@drcmda yes! I think --keepattributes is a good addition. I would only consider the remaining prune() flags on a case-by-case basis, perhaps in future PRs, they do not all translate to gltfjsx directly.

[hichemfantar]

Forgot to mention that I included some changes to the gitignore for proper yarn support according to https://yarnpkg.com/getting-started/qa#which-files-should-be-gitignored and some markdown linting fixes according to https://github.com/DavidAnson/markdownlint/

[hichemfantar]

Can we get this merged?
this was recently fixed in three but it's only available for future releases