MeshAttributeAccessor

 1const mesh = this.object.getComponent('mesh').mesh;
 2const positions = mesh.attribute(MeshAttribute.Position);
 3
 4// Equivalent to `new Float32Array(3)`.
 5const temp = positions.createArray();
 6
 7for(let i = 0; i < positions.length; ++i) {
 8    // `pos` will reference `temp` and thereby not allocate additional
 9    // memory, which would cause a perf spike when collected.
10    const pos = positions.get(i, temp);
11    // Scale position by 2 on x-axis only.
12    pos[0] *= 2.0;
13    positions.set(i, pos);
14}
15// We're done modifying, tell the engine to move vertex data to the GPU.
16mesh.update();

1const vertexCount = 4;
2const positionAttribute = mesh.attribute(MeshAttribute.Position);
3
4// A position has 3 floats per vertex. Thus, positions has length 3 * 4.
5const positions = positionAttribute.createArray(vertexCount);