trie-angles.js

const points = ["v1x", "v1y", "v1z", "v2x", "v2y", "v2z", "v3x", "v3y", "v3z"];

class Trie {
  children = {};

  insert(triangle, order = 0) {
    if (order === points.length) {
      return;
    }

    const k = triangle[order];

    if (this.children[k] === undefined) {
      this.children[k] = new Trie();
    }

    this.children[k].insert(triangle, order + 1);
  }

  getAllTriangles(key = null, order = 0, acc = {}, triangleStack = []) {
    const keys = Object.keys(this.children);

    if (key !== null) {
      acc = { ...acc, [points[order - 1]]: Number(key) };
    }

    if (order === points.length) {
      triangleStack.push(acc);
    }

    keys.forEach(k => {
      this.children[k].getAllTriangles(k, order + 1, acc, triangleStack);
    });

    return triangleStack;
  }
}

const flattenedTriangles = triangles.map(({ v1, v2, v3 }) => {
  // Ensure that vertices are "sorted" within the object
  [v1, v2, v3] = [v1, v2, v3].sort(
    (vA, vB) => vA.x - vB.x || vA.y - vB.y || vA.z - vB.z
  );

  return [v1.x, v1.y, v1.z, v2.x, v2.y, v2.z, v3.x, v3.y, v3.z];
});

const trie = new Trie();
flattenedTriangles.forEach(triangle => trie.insert(triangle));

console.log(trie.getAllTriangles());