[Bf-committers] Proposing a unique ID for Blender objects system, for use with game engines.

[Juan Linietsky]

Hi guys, lead Godot dev here.

I wanted to discuss with you a problem we are often having that I am not
certain how it can be solved entirely from our side, I add a proposal for
this, but if you guys have a better recommendation, I'm very open to any
ideas.

Basically, Godot will import scenes (GLTF/FBX/DAE/etc) as they come from
blender, and it generates the same object names, resource names, etc. as
they come from Blender and the resource file.

We use the same names so we can keep track of changes in the Blend file. If
an object is moved, a material is changed, etc. we detect on re-import and
everything is updated in Godot.

This is especially more annoying in Godot than in other game engines,
because Godot can read the whole Blender scene and keep it more or less
intact, so users love using this for level design workflow (so they can
design levels in Blender).

So, the problem is that it often happens that for some reason, artists want
to rename the objects in Blender. Be it because they didn't care at the
beginning and they want to become more organized later, or because the
scene became bigger and they need to make their naming of things more
precise to navigate it around. In this situation, when something is renamed
on the Blender side and re-exported, the game engines have no idea where
this object went, so we need to either remove it (resulting in loss data)
it or orphan it (resulting in duplicated data).

While I do think that good practices solve this and this is probably not
such an issue in a professional environment, truth is that game development
has become a huge hobbyist activity, and our users find this situation
constantly and are annoyed with it, and there is nothing we can do from our
side.

The obvious proposal to solve this would be to ask Blender whether it's
possible to generate a unique object ID (UUID?) and make sure it does not
change over time even if objects are renamed, then changing the exporters a
bit to (optionally if selected in the export settings) add this information
as extensions in the existing format (on GLTF it should be rather easy).

If you guys think this is possible, it would be very helpful for us, if you
have other ideas on how we could solve this, we are very open to discussion.

Best

Juan