How to set opacity in drawing lines use three.js, use LineBasicMaterial? - three.js

Question

I want to change lines' width and opacity,and my code as this:
var geometry_link = new THREE.Geometry();
geometry_link.vertices.push(
new THREE.Vector3(item[0].x *1,item[0].y *1,item[0].z),
new THREE.Vector3(item[1].x *1,item[1].y *1,item[1].z)
);
geometry_link.colors.push(
new THREE.Color(0x000000),
new THREE.Color(0xffffff)
);
var line = new THREE.Line(geometry_link, new THREE.LineBasicMaterial({
vertexColors: true,
linewidth: 8,
transparent: true,
opacity: 0.1
})
but it dose not work, both linewidth and opacity. I have found the similar question,said linewidth does not work on windows, that's 5 years ago, how about now?
Thanks for your idea

Answer 1

LineBasicMaterial does support transparent lines as demonstrated by the following live example:
let camera, scene, renderer;
init();
animate();
function init() {
camera = new THREE.PerspectiveCamera(70, window.innerWidth / window.innerHeight, 0.01, 10);
camera.position.z = 1;
scene = new THREE.Scene();
const geometry = new THREE.BufferGeometry().setFromPoints([new THREE.Vector3(), new THREE.Vector3(1, 0, 0)]);
const material = new THREE.LineBasicMaterial({
transparent: true,
opacity: 0.5
});
const mesh = new THREE.Line(geometry, material);
scene.add(mesh);
renderer = new THREE.WebGLRenderer({
antialias: true
});
renderer.setSize(window.innerWidth, window.innerHeight);
document.body.appendChild(renderer.domElement);
}
function animate() {
requestAnimationFrame(animate);
renderer.render(scene, camera);
}
body {
margin: 0;
}
canvas {
display: block;
}
<script src="https://cdn.jsdelivr.net/npm/three#0.119.1/build/three.js"></script>
Wide lines however are not supported. So setting linewidth to a different value like 1 has no effect in most browsers. This is a WebGL limitation in context of line primitives.
However, three.js provides a wide line implementation based on triangles (sometimes called mesh lines or ribbons). Check out the following example for more information:
https://threejs.org/examples/webgl_lines_fat