[Bf-committers] Proposal: Export extensions for better integration with game engines.

[Sybren A. Stüvel]

Hi Juan,

On Thu, 4 Mar 2021 at 19:05, Juan Linietsky via Bf-committers <
bf-committers at blender.org> wrote:

>    The main topic is the ability for Blender to have a "Metadata Export"
> plugin. This means, that at the time of export,and for each object exported
> (node, material, skeleton, mesh, etc) Blender should be able to ask for
> "metadata" to the export plugins.


Either I'm not understanding things well, or there is some inconsistency in
the terminology. It seems that what you're describing is actually more
"extra data" or "augmentation" of the exported file format. For example,
what you descsribe in export of materials, splines, IK properties, etc.
are, at least from Blender's point of view, data, and not metadata.

What I mean is that I see a difference between:

   - What is exported? This seems like both data (camera/light parameters,
   physics sim results) and metadata (like a name-invariant identifier).
   - How is it exported? Here you could indeed (mis)use free-form metadata
   fields of the export file format to contain the data you're interested in.

I think it's bad to focus on the last bit, though, because if a file format
natively supports the desired data, it should be exported in that way and
not crammed into some metadata string field.

So, all this could be done if exporters polled export metadata plugins for
> metadata at the time of export (so we ensure we convert from the most
> recent version of the object) on any object, then added it in the exported
> data. This is a minimal non-invasive change in Blender exporters, but adds
> huge flexibility to engine export.
>

I don't know if I'm such a fan of "any add-on can add anything to any
exporter". More often than not, with an everything-should-be-possible
super-flexible design, things get very hairy.

Why not work on the glTF or USD exporter, so that it gets more powerful and
actually exports everything game engines like Godot (and others, of course)
need?

Cheers,
Sybren