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Here you can Sed posuere consectetur est at lobortis. Donec ullamcorper nulla non metus auctor fringilla. Maecenas sed diam eget risus varius blandit sit amet non magna. Donec id elit non mi porta gravida at eget metus. Praesent commodo cursus magna, vel scelerisque nisl consectetur et.

HTML

            
              <canvas id="c"></canvas>
  
            
          
!

CSS

            
              body {
  margin: 0;
}
#c {
  width: 100vw;
  height: 100vh;
  display: block;
}

            
          
!

JS

            
              // Three.js - Picking - RayCaster w/Transparency
// from https://threejsfundamentals.org/threejs/threejs-picking-gpu.html

import * as THREE from "https://threejsfundamentals.org/threejs/resources/threejs/r113/build/three.module.js";

function main() {
  const canvas = document.querySelector("#c");
  const renderer = new THREE.WebGLRenderer({ canvas });

  const fov = 60;
  const aspect = 2; // the canvas default
  const near = 0.1;
  const far = 200;
  const camera = new THREE.PerspectiveCamera(fov, aspect, near, far);
  camera.position.z = 30;

  const scene = new THREE.Scene();
  scene.background = new THREE.Color(0);
  const pickingScene = new THREE.Scene();
  pickingScene.background = new THREE.Color(0);

  // put the camera on a pole (parent it to an object)
  // so we can spin the pole to move the camera around the scene
  const cameraPole = new THREE.Object3D();
  scene.add(cameraPole);
  cameraPole.add(camera);

  function randomNormalizedColor() {
    return Math.random();
  }

  function getRandomInt(n) {
    return Math.floor(Math.random() * n);
  }

  function getCanvasRelativePosition(e) {
    const rect = canvas.getBoundingClientRect();
    return {
      x: e.clientX - rect.left,
      y: e.clientY - rect.top
    };
  }

  const textureLoader = new THREE.TextureLoader();
  const particleTexture =
    "https://raw.githubusercontent.com/mrdoob/three.js/master/examples/textures/sprites/ball.png";

  const vertexShader = `
    attribute float size;
    attribute vec3 customColor;

    varying vec3 vColor;

    void main() {
        vColor = customColor;
        vec4 mvPosition = modelViewMatrix * vec4( position, 1.0 );
        gl_PointSize = size * ( 100.0 / length( mvPosition.xyz ) );
        gl_Position = projectionMatrix * mvPosition;
    }
`;

  const fragmentShader = `
    uniform sampler2D texture;
    varying vec3 vColor;

    void main() {
        vec4 tColor = texture2D( texture, gl_PointCoord );
        if (tColor.a < 0.5) discard;
        gl_FragColor = mix( vec4( vColor.rgb, 1.0 ), tColor, 0.1 );
    }
`;

  const pickFragmentShader = `
    uniform sampler2D texture;
    varying vec3 vColor;

    void main() {
      vec4 tColor = texture2D( texture, gl_PointCoord );
      if (tColor.a < 0.25) discard;
      gl_FragColor = vec4( vColor.rgb, 1.0);
    }
`;

  const materialSettings = {
    uniforms: {
      texture: {
        type: "t",
        value: textureLoader.load(particleTexture)
      }
    },
    vertexShader: vertexShader,
    fragmentShader: fragmentShader,
    blending: THREE.NormalBlending,
    depthTest: true,
    transparent: false
  };

  const createParticleMaterial = () => {
    const material = new THREE.ShaderMaterial(materialSettings);
    return material;
  };

  const createPickingMaterial = () => {
    const material = new THREE.ShaderMaterial({
      ...materialSettings,
      fragmentShader: pickFragmentShader,
      blending: THREE.NormalBlending
    });
    return material;
  };

  const geometry = new THREE.BufferGeometry();
  const pickingGeometry = new THREE.BufferGeometry();
  const colors = [];
  const sizes = [];
  const pickingColors = [];
  const pickingColor = new THREE.Color();
  const positions = [];

  for (let i = 0; i < 30; i++) {
    colors[3 * i] = randomNormalizedColor();
    colors[3 * i + 1] = randomNormalizedColor();
    colors[3 * i + 2] = randomNormalizedColor();

    const rgbPickingColor = pickingColor.setHex(i + 1);
    pickingColors[3 * i] = rgbPickingColor.r;
    pickingColors[3 * i + 1] = rgbPickingColor.g;
    pickingColors[3 * i + 2] = rgbPickingColor.b;

    sizes[i] = getRandomInt(20);

    positions[3 * i] = getRandomInt(20);
    positions[3 * i + 1] = getRandomInt(20);
    positions[3 * i + 2] = getRandomInt(20);
  }

  geometry.setAttribute(
    "position",
    new THREE.Float32BufferAttribute(positions, 3)
  );
  geometry.setAttribute(
    "customColor",
    new THREE.Float32BufferAttribute(colors, 3)
  );
  geometry.setAttribute("size", new THREE.Float32BufferAttribute(sizes, 1));

  geometry.computeBoundingBox();

  const material = createParticleMaterial();
  const points = new THREE.Points(geometry, material);

  // setup geometry and material for GPU picking
  pickingGeometry.setAttribute(
    "position",
    new THREE.Float32BufferAttribute(positions, 3)
  );
  pickingGeometry.setAttribute(
    "customColor",
    new THREE.Float32BufferAttribute(pickingColors, 3)
  );
  pickingGeometry.setAttribute(
    "size",
    new THREE.Float32BufferAttribute(sizes, 1)
  );

  pickingGeometry.computeBoundingBox();

  const pickingMaterial = createPickingMaterial();
  const pickingPoints = new THREE.Points(pickingGeometry, pickingMaterial);

  scene.add(points);
  pickingScene.add(pickingPoints);

  function resizeRendererToDisplaySize(renderer) {
    const canvas = renderer.domElement;
    const width = canvas.clientWidth;
    const height = canvas.clientHeight;
    const needResize = canvas.width !== width || canvas.height !== height;
    if (needResize) {
      renderer.setSize(width, height, false);
    }
    return needResize;
  }

  class GPUPickHelper {
    constructor() {
      // create a 1x1 pixel render target
      this.pickingTexture = new THREE.WebGLRenderTarget(1, 1);
      this.pixelBuffer = new Uint8Array(4);
    }
    pick(cssPosition, pickingScene, camera) {
      const { pickingTexture, pixelBuffer } = this;

      // set the view offset to represent just a single pixel under the mouse
      const pixelRatio = renderer.getPixelRatio();
      camera.setViewOffset(
        renderer.getContext().drawingBufferWidth, // full width
        renderer.getContext().drawingBufferHeight, // full top
        (cssPosition.x * pixelRatio) | 0, // rect x
        (cssPosition.y * pixelRatio) | 0, // rect y
        1, // rect width
        1 // rect height
      );
      // render the scene
      renderer.setRenderTarget(pickingTexture);
      renderer.render(pickingScene, camera);
      renderer.setRenderTarget(null);
      // clear the view offset so rendering returns to normal
      camera.clearViewOffset();
      //read the pixel
      renderer.readRenderTargetPixels(
        pickingTexture,
        0, // x
        0, // y
        1, // width
        1, // height
        pixelBuffer
      );

      const id =
        (pixelBuffer[0] << 16) | (pixelBuffer[1] << 8) | pixelBuffer[2];
      
      console.log(`You clicked sphere number ${id}`);
      
      return id;
    }
  }

  const pickHelper = new GPUPickHelper();

  function render(time) {
    time *= 0.001; // convert to seconds;

    if (resizeRendererToDisplaySize(renderer)) {
      const canvas = renderer.domElement;
      camera.aspect = canvas.clientWidth / canvas.clientHeight;
      camera.updateProjectionMatrix();
    }

    cameraPole.rotation.y = time * 0.1;

    renderer.render(scene, camera);

    requestAnimationFrame(render);
  }
  requestAnimationFrame(render);

  function onClick(e) {
    const pickPosition = getCanvasRelativePosition(e);
    const pickedID = pickHelper.pick(pickPosition, pickingScene, camera);
  }

  function onTouch(e) {
    const touch = e.touches[0];
    const pickPosition = getCanvasRelativePosition(touch);
    const pickedID = pickHelper.pick(pickPosition, pickingScene, camera);
  }

  window.addEventListener("mousedown", onClick);
  window.addEventListener("touchstart", onTouch);
}

main();

            
          
!
999px

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