.points的不透明度/大小在three.js之内 [英] .points opacity / size within three.js
问题描述
我回来回答关于.point的第二个问题.这次想知道如何将不透明度从0更改为1，然后在距发射器一定的像素距离内返回.
I'm back for question two on .points. This time wondering how to change the opacity from 0, to 1 and then back within certain pixel distances from the emitter.
var particleCount = 14,
particles = new THREE.Geometry(),
pMaterial = new THREE.PointsMaterial({
map: new THREE.TextureLoader().load("x.png"),
blending: THREE.multiplyBlending,
flatShading: true,
size: 40,
transparent: true,
depthTest: true,
sizeAttenuation: true,
opacity: 1
});
var particleSystem;
我的主要困惑是，即使我赋予它透明性，我也无法在为发射器制作的update comp内更改该值.
My main confusion is that even though I've given it transparency I can't change the value within the update comp I've made for my emitter.
function update() {
//particleSystem.rotation.y += 0.01;
pCount = particleCount;
while (pCount--) {
particle = particles.vertices[pCount];
(这是一堆验证点所在的地方)
(This is where a bunch of validation is for where the points are)
particleSystem.geometry.verticesNeedUpdate = true;
particleSystem.rotation.y += (Math.random()*0.001)
}
渲染循环:
renderer.setAnimationLoop(() => {
update();
composer.render(scene, camera);
});
我想使其淡出，并且不出现在场景中约20个像素，然后再淡入.但是我不确定如何更改不透明度，因为particle.opacity + = 0.1无效
I want to make it fade out and not appear in the scene for 20 or so pixels and then fade in. But I'm not entirely sure on how to change the opacity as particle.opacity += 0.1 won't work.
我也不确定Size，因为我想对它做类似的事情，但是从20到40，我可能会根据它的Y坐标确定它的基数.反正;我也不确定如何逐步改变这种情况.
I'm also uncertain about Size as I want to do a similar thing with it but from 20 to 40, I could probably base it depending on it's Y cordinate. Anyway; I'm also uncertain how to gradually change that too.
很抱歉，如果这是一个显而易见的答案，重复的问题以及我得到的任何帮助.我所见过的任何替代方法都位于我不了解的替代结构中，或者位于不知道如何放入所需内容的数组中.
Sorry if this is a obvious answer, duplicate question and any help I get. Any alternate methods of what I've seen is in an alternate structure that I don't understand or in array in which I don't know how to put into what I want.
(提前感谢)
推荐答案
问题是不透明度和大小是 THREE.Points .必须有一个包含不同HREE.PointsMaterial的不同THREE.Points的列表.
The issue is that the opacity and the size is a property of the THREE.PointsMaterial. If the pints should have different sizes it is not sufficient to have a list of different vertices in one THREE.Points. There has to be a list of different THREE.Points with different HREE.PointsMaterials.
用不同的材料创建THREE.Points的列表:
Create a list of THREE.Points with different materials:
var texture = new THREE.TextureLoader().load( "..." );
var particleSystemCount = 14;
var particleSystems = [];
for (var i = 0; i < particleSystemCount; ++ i) {
var geometry = new THREE.Geometry();
var pMaterial = new THREE.PointsMaterial({
size: 20,
map: texture,
blending: THREE.AdditiveBlending,
transparent: true,
depthTest: false,
sizeAttenuation: true,
opacity: 0
});
// ...
var points = new THREE.Points(geometry, pMaterial);
scene.add(points);
particleSystems.push(points);
}
因此在update中，不透明度和大小可以分别更改:
So in update the opacity and size can be changed individually:
function update() {
for (var i = 0; i < particleSystems.length; ++ i) {
var points = particleSystems[i];
var material = points.material;
var particle = points.geometry.vertices[0];
// ....
if ( material.size < 40 )
material.size += 0.5;
if ( material.opacity < 1 )
material.opacity += 0.01;
// ....
}
}
var canvas_w = window.innerWidth, canvas_h = window.innerHeight;
var scene = new THREE.Scene();
var camera = new THREE.PerspectiveCamera(60, canvas_w/canvas_h, 1, 1000);
camera.position.set(0, 0, 400);
var renderer = new THREE.WebGLRenderer();
renderer.setSize(canvas_w, window.innerHeight);
document.body.appendChild(renderer.domElement);
window.onresize = function() {
canvas_w = window.innerWidth, canvas_h = window.innerHeight;
renderer.setSize(canvas_w, canvas_h);
camera.aspect = canvas_w/canvas_h;
camera.updateProjectionMatrix();
}
var texture = new THREE.TextureLoader().load("https://threejs.org/examples/textures/sprites/circle.png");
var particleSystemCount = 14;
var particleSystems = [];
for (var i = 0; i < particleSystemCount; ++ i) {
var geometry = new THREE.Geometry();
var pMaterial = new THREE.PointsMaterial({
size: 20,
map: texture,
blending: THREE.AdditiveBlending,
transparent: true,
depthTest: false,
sizeAttenuation: true,
opacity: 0
});
var px = (Math.random() - 0.5) * 100;
var py = (Math.random() - 0.5) * 100 + 200;
var pz = (Math.random() - 0.5) * 100;
var particle = new THREE.Vector3(px, py, pz);
particle.velocity = new THREE.Vector3(0, 0, 0);
geometry.vertices.push(particle);
var points = new THREE.Points(geometry, pMaterial);
scene.add(points);
particleSystems.push(points);
}
function update() {
for (var i = 0; i < particleSystems.length; ++ i) {
var points = particleSystems[i];
var material = points.material;
var particle = points.geometry.vertices[0];
if (particle.y < -200) {
particle.x = (Math.random() - 0.5) * 100;
particle.y = (Math.random() - 0.5) * 100 + 200;
particle.z = (Math.random() - 0.5) * 100;
particle.velocity.y = 0;
material.size = 20;
material.opacity = 0;
}
particle.velocity.y -= Math.random() * .1;
particle.add(particle.velocity);
if ( material.size < 40 )
material.size += 0.25;
if ( material.opacity < 1 )
material.opacity += 0.01;
points.geometry.verticesNeedUpdate = true;
points.rotation.y += (Math.random()*0.001)
}
}
renderer.setAnimationLoop(() => {
update();
renderer.render(scene, camera);
});
body { overflow: hidden; margin: 0; }
<script src="https://cdnjs.cloudflare.com/ajax/libs/three.js/99/three.min.js"></script>
这篇关于.points的不透明度/大小在three.js之内的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
