three-geometry-data

Returns individual vertex data from an indexed THREE.Geometry in ThreeJS.

This is useful to extract the normals, UV coordinates, colors, and positions of each vertex without losing the face ordering. By default, ThreeJS stores this data in such a way that it is difficult to, for example, iterate over each unique normal in a mesh.

const getVertexData = require('three-geometry-data');

const geometry = new THREE.BoxGeometry(1, 1, 1);
const { faces, attributes } = getVertexData(geometry);

// list all vertices
faces.forEach(([ a, b, c ]) => {
  // a THREE.Vector3
  console.log(attributes.position[a]);
  console.log(attributes.position[b]);
  console.log(attributes.position[c]);
});

Where faces is a listed of nested face indices for each triangle:

[ [0, 2, 1], [2, 3, 1], ... ]

And attributes is an object with the named attributes in an array of Vectors, such as:

{
  position: [ THREE.Vector3(0.5, 0.5, 0.5), ... ],
  normal: [ THREE.Vector3(1, 0, 0), ... ],
  uv: [ THREE.Vector2(0, 1), ... ]
}

If multiple sets of UVs exist, they will be named uv, then uv1, uv2, etc.

Install

Use npm to install.

npm install three-geometry-data --save

Usage

{ faces, attributes } = getVertexData(geometry)

Returns the faces and attributes of an indexed THREE.Geometry instance by unrolling the face data into arrays of Vector data.

License

MIT, see LICENSE.md for details.