# How to extrude from 2D points with BufferGeometry?
**URL:** https://discourse.threejs.org/t/how-to-extrude-from-2d-points-with-buffergeometry/40967
**Category:** Questions
**Tags:** geometry
**Created:** [August 2, 2022, 2:01pm UTC](https://discourse.threejs.org/t/how-to-extrude-from-2d-points-with-buffergeometry/40967 "2022-08-02T14:01:58Z")
**Posts on this page:** 6
**Page:** 1
### Author:  [@Bossie](https://discourse.threejs.org/u/Bossie)
#### Post date: [August 2, 2022, 2:01pm UTC](https://discourse.threejs.org/t/how-to-extrude-from-2d-points-with-buffergeometry/40967/1 "2022-08-02T14:01:58Z")
I used the function below to create custom geometry from 2D points.
```javascript
/**
* Code from: https://stackoverflow.com/a/29969348
* @param points
* @param depth
* @returns {PlaneGeometry}
*/
extrudePath(points, depth) {
const geometry = new THREE.PlaneGeometry(0, 0, points.length - 1, 1);
const vertices = geometry.vertices;
for (let i = 0, l = points.length, p; i < l; i++) {
p = points[i];
vertices[i].x = vertices[i + l].x = p[0];
vertices[i].y = vertices[i + l].y = p[1];
vertices[i].z = p[2];
vertices[i + l].z = p[2] + depth;
}
geometry.computeFaceNormals();
return geometry;
}
```
Plain and simple, and much needed in the configurators I’m creating.
However this function doesn’t work anymore using a newer version of Three which only supports BufferGeometry.
How do I change the function to support BufferGeometry?
I am aware that I can extrude a shape defined by 2D points, but it seems that the shape always wants to close itself.
---
### Author:  [@prisoner849](https://discourse.threejs.org/u/prisoner849)
#### Post date: [August 2, 2022, 2:31pm UTC](https://discourse.threejs.org/t/how-to-extrude-from-2d-points-with-buffergeometry/40967/2 "2022-08-02T14:31:57Z")
Hi!
You can do it this way: [https://codepen.io/prisoner849/pen/VwXMmvZ?editors=0010](https://codepen.io/prisoner849/pen/VwXMmvZ?editors=0010)
```javascript
function extrudePath(points, depth) {
let geometry = new THREE.PlaneGeometry(0, 0, points.length - 1, 1);
let pos = geometry.attributes.position;
for (let i = 0, l = points.length, p; i < l; i++) {
let p = points[i];
pos.setXYZ(i, p.x, p.y, p.z + depth);
pos.setXYZ(i + points.length, p.x, p.y, p.z)
}
geometry.computeVertexNormals();
return geometry;
}
```
---
### Author:  [@Bossie](https://discourse.threejs.org/u/Bossie)
#### Post date: [August 2, 2022, 2:39pm UTC](https://discourse.threejs.org/t/how-to-extrude-from-2d-points-with-buffergeometry/40967/3 "2022-08-02T14:39:05Z")
Thanks a lot for the quick answer, works like a charm!
---
### Author:  [@prisoner849](https://discourse.threejs.org/u/prisoner849)
#### Post date: [August 2, 2022, 2:39pm UTC](https://discourse.threejs.org/t/how-to-extrude-from-2d-points-with-buffergeometry/40967/4 "2022-08-02T14:39:36Z")
You’re welcome 🍻 🤝
---
### Author:  [@Bossie](https://discourse.threejs.org/u/Bossie)
#### Post date: [August 3, 2022, 6:57am UTC](https://discourse.threejs.org/t/how-to-extrude-from-2d-points-with-buffergeometry/40967/5 "2022-08-03T06:57:44Z")
Another question, the shading looks weird, see screenshot:
How should I fix this?
---
### Author:  [@Bossie](https://discourse.threejs.org/u/Bossie)
#### Post date: [August 3, 2022, 12:24pm UTC](https://discourse.threejs.org/t/how-to-extrude-from-2d-points-with-buffergeometry/40967/6 "2022-08-03T12:24:57Z")
Ok this took me a while to figure out, but I fixed it by converting the new geometry to non-indexed geometry using geometry.toNonIndexed(), this allows for “hard corners” for as far as I think I understand normals 😃
And after that calling geometry.computeVertexNormals()