Question

我使用three.js进行wave画布动画，但是我不知道如何删除画布的背景色（仅背景色）。

if (WEBGL.isWebGLAvailable() === false) {
  document.body.appendChild(WEBGL.getWebGLErrorMessage());
}

var SEPARATION = 100,
  AMOUNTX = 50,
  AMOUNTY = 50;

var container, stats;
var camera, scene, renderer;

var particles,
  count = 0;

var mouseX = 0,
  mouseY = -450;

var windowHalfX = window.innerWidth / 2;
var windowHalfY = window.innerHeight / 2;

init();
animate();

function init() {
  container = document.createElement("div");
  document.body.appendChild(container);

  camera = new THREE.PerspectiveCamera(
    75,
    window.innerWidth / window.innerHeight,
    1,
    10000,
  );
  camera.position.z = 1000;

  scene = new THREE.Scene();

  var numParticles = AMOUNTX * AMOUNTY;

  var positions = new Float32Array(numParticles * 3);
  var scales = new Float32Array(numParticles);

  var i = 0,
    j = 0;

  for (var ix = 0; ix < AMOUNTX; ix++) {
    for (var iy = 0; iy < AMOUNTY; iy++) {
      positions[i] = ix * SEPARATION - (AMOUNTX * SEPARATION) / 2; // x
      positions[i + 1] = 0; // y
      positions[i + 2] = iy * SEPARATION - (AMOUNTY * SEPARATION) / 2; // z

      scales[j] = 1;

      i += 3;
      j++;
    }
  }

  var geometry = new THREE.BufferGeometry();
  geometry.addAttribute("position", new THREE.BufferAttribute(positions, 3));
  geometry.addAttribute("scale", new THREE.BufferAttribute(scales, 1));

  var material = new THREE.ShaderMaterial({
    uniforms: {
      color: { value: new THREE.Color(0xffffff) },
    },
    vertexShader: document.getElementById("vertexshader").textContent,
    fragmentShader: document.getElementById("fragmentshader").textContent,
  });

  particles = new THREE.Points(geometry, material);
  scene.add(particles);

  renderer = new THREE.WebGLRenderer({ antialias: true });
  renderer.setPixelRatio(window.devicePixelRatio);
  renderer.setSize(window.innerWidth, window.innerHeight);
  renderer.domElement.id = "outerTest";
  container.appendChild(renderer.domElement);

  document.addEventListener("mousemove", onDocumentMouseMove, false);
  document.addEventListener("touchstart", onDocumentTouchStart, false);
  document.addEventListener("touchmove", onDocumentTouchMove, false);

  window.addEventListener("resize", onWindowResize, false);
}

function onWindowResize() {
  windowHalfX = window.innerWidth / 2;
  windowHalfY = window.innerHeight / 2;

  camera.aspect = window.innerWidth / window.innerHeight;
  camera.updateProjectionMatrix();

  renderer.setSize(window.innerWidth, window.innerHeight);
}

//

function onDocumentMouseMove(event) {
  mouseX = event.clientX - windowHalfX;
  mouseY = event.clientY - windowHalfY;
}

function onDocumentTouchStart(event) {
  if (event.touches.length === 1) {
    event.preventDefault();

    mouseX = event.touches[0].pageX - windowHalfX;
    mouseY = event.touches[0].pageY - windowHalfY;
  }
}

function onDocumentTouchMove(event) {
  if (event.touches.length === 1) {
    event.preventDefault();

    mouseX = event.touches[0].pageX - windowHalfX;
    mouseY = event.touches[0].pageY - windowHalfY;
  }
}

//

function animate() {
  requestAnimationFrame(animate);

  render();
  //stats.update();
}

function render() {
  camera.position.x += (mouseX - camera.position.x) * 0.05;
  camera.position.y += (-mouseY - camera.position.y) * 0.05;
  camera.lookAt(scene.position);

  var positions = particles.geometry.attributes.position.array;
  var scales = particles.geometry.attributes.scale.array;

  var i = 0,
    j = 0;

  for (var ix = 0; ix < AMOUNTX; ix++) {
    for (var iy = 0; iy < AMOUNTY; iy++) {
      positions[i + 1] =
        Math.sin((ix + count) * 0.3) * 50 + Math.sin((iy + count) * 0.5) * 50;

      scales[j] =
        (Math.sin((ix + count) * 0.3) + 1) * 8 +
        (Math.sin((iy + count) * 0.5) + 1) * 8;

      i += 3;
      j++;
    }
  }

  particles.geometry.attributes.position.needsUpdate = true;
  particles.geometry.attributes.scale.needsUpdate = true;

  renderer.render(scene, camera);

  count += 0.1;
}

plz忽略：为了真正能够使用three.js显示任何内容，我们需要三件事：场景，相机和渲染器，以便我们可以使用相机渲染场景。

Answer 1

在您的webglrenderer构造函数中

传递alpha：true，preserveDrawingBuffer：true

确保您的canvas元素没有设置style.background。即确保将其设置为“

Transparent background with three.js

波js背景色

1 个答案: