BufferAttribute setVector & setColor convenience methods

[Kodub]

Description

This PR adds new convenience methods to BufferAttribute & InterleavedBufferAttribute.

• setVector2()
• setVector3()
• setVector4()
• setColor()

These helps simplify setting vectors and colors which seem to be a quite common pattern as most instances of setXYZ are possible to change into these new convenience methods.

Before:

const v = new THREE.Vector3(1, 2, 3);
attribute.setXYZ(0, v.x, v.y, v.z);

const c = new THREE.Color(0.1, 0.2, 0.3);
attribute.setXYZ(1, c.r, c.g, c.b);

After:

const v = new THREE.Vector3(1, 2, 3);
attribute.setVector3(0, v);

const c = new THREE.Color(0.1, 0.2, 0.3);
attribute.setColor(1, c);

Advantages

• Shorter code
• Helps prevent hard to spot mistakes. For example: attribute.setXYZ(0, v.x, v.x, v.z);

Discussion points

• Other possible names are setXYZFromVector3 and setXYZFromColorRGB. Would these names be preferred to make it clearer that these are convenience methods for setXYZ?
• Right now these methods simply call their respective setXYZ methods. The extra function call might introduce a small performance overhead.

[github-actions]

📦 Bundle size

Full ESM build, minified and gzipped.

	Before	After	Diff
WebGL	360.57 85.58	360.57 85.58	+0 B +0 B
WebGPU	635.48 176.41	635.48 176.41	+0 B +0 B
WebGPU Nodes	633.6 176.11	633.6 176.11	+0 B +0 B

🌳 Bundle size after tree-shaking

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

	Before	After	Diff
WebGL	492.95 120.2	493.07 120.21	+120 B +7 B
WebGPU	707.66 191.31	707.96 191.31	+294 B +3 B
WebGPU Nodes	656.88 178.57	657.18 178.61	+294 B +41 B