Core: Increase version of Object/Scene format.

[repalash]

Fixes: #31095

Description

Updated the version to 4.7 in Material.toJSON, can do the same for other classes - Object3D, BufferGeometry etc if you want to keep it consistent.

The handling of bumpScale was changed in #26899, which is saved in Material.toJSON.

To distinguish between old and new files metadata.version is checked while loading, so that either a warning can be shown to the user or some heuristic can be used to automatically adjust the value.

This contribution is funded by ThreePipe

[github-actions]

📦 Bundle size

Full ESM build, minified and gzipped.

	Before	After	Diff
WebGL	337.26 78.64	337.26 78.64	+0 B +0 B
WebGPU	550.09 152.49	550.09 152.49	+0 B +0 B
WebGPU Nodes	549.45 152.33	549.45 152.33	+0 B +0 B

🌳 Bundle size after tree-shaking

Minimal build including a renderer, camera, empty scene, and dependencies.

	Before	After	Diff
WebGL	468.12 113.14	468.12 113.14	+0 B +0 B
WebGPU	625.46 169.27	625.46 169.27	+0 B +0 B
WebGPU Nodes	580.32 158.58	580.32 158.58	+0 B +0 B

[mrdoob]

Updated the version to 4.7 in Material.toJSON, can do the same for other classes - Object3D, BufferGeometry etc if you want to keep it consistent.

Yeah, lets keep it consistent 🙏

[repalash]

Done for all the places the json version was 4.6

[Mugen87]

FYI: I've noted the version bump in the migration guide, just to be on the safe side^^:

https://github.com/mrdoob/three.js/wiki/Migration-Guide#176--177