MeshLine

Mesh replacement for THREE.Line

Instead of using GL_LINE, it uses a strip of triangles billboarded. Some examples:

Demo: play with the different settings of materials
Graph: example of using MeshLine to plot graphs
Spinner: example of dynamic MeshLine with texture
SVG: example of MeshLine rendering SVG Paths
Shape: example of MeshLine created from a mesh
Birds: example of MeshLine.advance() by @caramelcode (Jared Sprague) and @mwcz (Michael Clayton)

How to use

Include script
Create an array of 3D coordinates
Create a MeshLine and assign the points
Create a MeshLineMaterial
Use MeshLine and MeshLineMaterial to create a THREE.Mesh

Include the script

Include script after THREE is included

<script src="https://github.com/spite/THREE.MeshLine/raw/master/THREE.MeshLine.js"></script>

or use npm to install it

npm i three.meshline

and include it in your code (don't forget to require three.js)

const THREE = require('three');
const MeshLine = require('three.meshline').MeshLine;
const MeshLineMaterial = require('three.meshline').MeshLineMaterial;
const MeshLineRaycast = require('three.meshline').MeshLineRaycast;

import * as THREE from 'three';
import { MeshLine, MeshLineMaterial, MeshLineRaycast } from 'three.meshline';

Create an array of 3D coordinates

First, create the list of numbers that will define the 3D points for the line.

const points = [];
for (let j = 0; j < Math.PI; j += (2 * Math.PI) / 100) {
  points.push(Math.cos(j), Math.sin(j), 0);
}

MeshLine also accepts a BufferGeometry looking up the vertices in it.

const points = [];
for (let j = 0; j < Math.PI; j += 2 * Math.PI / 100) {
  points.push(new THREE.Vector3(Math.cos(j), Math.sin(j), 0));
}
const geometry = new THREE.BufferGeometry().setFromPoints(points);
const line = new MeshLine();
line.setGeometry(geometry);

Create a MeshLine and assign the points

Once you have that, you can create a new MeshLine, and call .setPoints() passing the list of points.

const line = new MeshLine();
line.setPoints(points);

Note: .setPoints accepts a second parameter, which is a function to define the width in each point along the line. By default that value is 1, making the line width 1 * lineWidth in the material.

// p is a decimal percentage of the number of points
// ie. point 200 of 250 points, p = 0.8
line.setPoints(geometry, p => 2); // makes width 2 * lineWidth
line.setPoints(geometry, p => 1 - p); // makes width taper
line.setPoints(geometry, p => 2 + Math.sin(50 * p)); // makes width sinusoidal

Create a MeshLineMaterial

A MeshLine needs a MeshLineMaterial:

const material = new MeshLineMaterial(OPTIONS);

By default it's a white material of width 1 unit.

MeshLineMaterial has several attributes to control the appereance of the MeshLine:

map - a THREE.Texture to paint along the line (requires useMap set to true)
useMap - tells the material to use map (0 - solid color, 1 use texture)
alphaMap - a THREE.Texture to use as alpha along the line (requires useAlphaMap set to true)
useAlphaMap - tells the material to use alphaMap (0 - no alpha, 1 modulate alpha)
repeat - THREE.Vector2 to define the texture tiling (applies to map and alphaMap - MIGHT CHANGE IN THE FUTURE)
color - THREE.Color to paint the line width, or tint the texture with
opacity - alpha value from 0 to 1 (requires transparent set to true)
alphaTest - cutoff value from 0 to 1
dashArray - the length and space between dashes. (0 - no dash)
dashOffset - defines the location where the dash will begin. Ideal to animate the line.
dashRatio - defines the ratio between that is visible or not (0 - more visible, 1 - more invisible).
resolution - THREE.Vector2 specifying the canvas size (REQUIRED)
sizeAttenuation - makes the line width constant regardless distance (1 unit is 1px on screen) (0 - attenuate, 1 - don't attenuate)
lineWidth - float defining width (if sizeAttenuation is true, it's world units; else is screen pixels)

If you're rendering transparent lines or using a texture with alpha map, you should set depthTest to false, transparent to true and blending to an appropriate blending mode, or use alphaTest.

Use MeshLine and MeshLineMaterial to create a THREE.Mesh

Finally, we create a mesh and add it to the scene:

const mesh = new THREE.Mesh(line, material);
scene.add(mesh);

You can optionally add raycast support with the following.

mesh.raycast = MeshLineRaycast;

Declarative use

THREE.meshline can be used declaritively. This is how it would look like in react-three-fiber. You can try it live here.

import { extend, Canvas } from 'react-three-fiber'
import { MeshLine, MeshLineMaterial, MeshLineRaycast } from 'three.meshline'

extend({ MeshLine, MeshLineMaterial })

function Line({ points, width, color }) {
  return (
    <Canvas>
      <mesh raycast={MeshLineRaycast}>
        <meshLine attach="geometry" points={points} />
        <meshLineMaterial
          attach="material"
          transparent
          depthTest={false}
          lineWidth={width}
          color={color}
          dashArray={0.05}
          dashRatio={0.95}
        />
      </mesh>
    </Canvas>
  )
}

Dynamic line widths can be set along each point using the widthCallback prop.

<meshLine attach='geometry' points={points} widthCallback={pointWidth => pointWidth * Math.random()} />

TODO

Better miters
Proper sizes

Support

Tested successfully on

Chrome OSX, Windows, Android
Firefox OSX, Windows, Anroid
Safari OSX, iOS
Internet Explorer 11 (SVG and Shape demo won't work because they use Promises)
Opera OSX, Windows

References

License

MIT licensed

spite / THREE.MeshLine

readme