function createWireframeFromTriangles(vertexCount) {
  const wireframeIndices = IndexDatatype.createTypedArray(
    vertexCount,
    vertexCount * 2,
  );
  const length = vertexCount;
  let index = 0;
  for (let i = 0; i < length; i += 3) {
    wireframeIndices[index++] = i;
    wireframeIndices[index++] = i + 1;
    wireframeIndices[index++] = i + 1;
    wireframeIndices[index++] = i + 2;
    wireframeIndices[index++] = i + 2;
    wireframeIndices[index++] = i;
  }

  return wireframeIndices;
}
Functions for generating indices for model wireframes. The indices are
outputted as typed arrays, which can then be put into buffers for rendering.

@namespace WireframeIndexGenerator
@private