Object3D: Document static, add support in copy() and JSON.

[Mugen87]

Related issue: -

Description

The PR documents Object3D.static, a new property that has been introduced in the last year for WebGPURenderer. It has been monkey-patched in the performance examples (e.g. webgpu_performance) so far. This PR introduces documentation, copy() and serialization/deserialization support.

The property itself is a hint for the renderer to improve performance when processing render objects. When set to true, the renderer assumes no aspects of the object change over time including geometry and material settings. This allows the renderer to bypass checks that determine whether the render object needs updated bindings, geometry data etc.

[github-actions]

📦 Bundle size

Full ESM build, minified and gzipped.

	Before	After	Diff
WebGL	355.36 84.47	355.36 84.47	+0 B +0 B
WebGPU	621.54 172.59	621.54 172.59	+0 B +0 B
WebGPU Nodes	620.15 172.35	620.15 172.35	+0 B +0 B

🌳 Bundle size after tree-shaking

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

	Before	After	Diff
WebGL	487.23 119.23	487.31 119.25	+77 B +24 B
WebGPU	692.46 187.82	692.53 187.85	+77 B +25 B
WebGPU Nodes	642.26 175.05	642.34 175.07	+77 B +25 B