Get the exact vertex coordinates from the attributes for interpolation calculations

Questions
,
2

Hi!
Pass vertex data in buffer attributes.
For example, here: Project MONOLITH
There is setAttributes() function, that has that code:

  let pos = g.attributes.position;
  let faces = pos.count / 3;
  let faceVerts = [
    new THREE.Vector3(),
    new THREE.Vector3(),
    new THREE.Vector3()
  ];
  let position2 = [];
  let position3 = [];
  
  for (let i = 0; i < faces; i++) {
    faceVerts[0].fromBufferAttribute(pos, i * 3 + 0);
    faceVerts[1].fromBufferAttribute(pos, i * 3 + 1);
    faceVerts[2].fromBufferAttribute(pos, i * 3 + 2);
    for (let v = 0; v < 3; v++) {
      let v2 = faceVerts[(v + 1) % 3];
      let v3 = faceVerts[(v + 2) % 3];
      position2.push(v2.x, v2.y, v2.z);
      position3.push(v3.x, v3.y, v3.z);
    }
  }

  g.setAttribute("position2", new THREE.Float32BufferAttribute(position2, 3));
  g.setAttribute("position3", new THREE.Float32BufferAttribute(position3, 3));

(lines 426-449 in JS section)
and in the vertex shader I simply do this:

        attribute vec3 position2;
        attribute vec3 position3;

(lines 71-72 in JS section)