examples/instancing.html

<!DOCTYPE html>
<html>
  <head>
    <meta charset="utf8">
    <!--

    @license twgl.js Copyright (c) 2015, Gregg Tavares All Rights Reserved.
    Available via the MIT license.
    see: http://github.com/greggman/twgl.js for details

    -->
    <meta name="viewport" content="width=device-width, initial-scale=1.0, user-scalable=yes">
    <meta property="og:title" content="TWGL.js - instancing" />
    <meta property="og:type" content="website" />
    <meta property="og:image" content="http://twgljs.org/examples/screenshots/instancing.png" />
    <meta property="og:description" content="TWGL.js - instancing" />
    <meta property="og:url" content="http://twgljs.org" />

    <meta name="twitter:card" content="summary_large_image">
    <meta name="twitter:site" content="@greggman">
    <meta name="twitter:creator" content="@greggman">
    <meta name="twitter:domain" content="twgljs.org">
    <meta name="twitter:title" content="TWGL.js - instancing">
    <meta name="twitter:url" content="http://twgljs.org/examples/instancing.html">
    <meta name="twitter:description" content="TWGL.js - instancing">
    <meta name="twitter:image:src" content="http://twgljs.org/examples/screenshots/instancing.png">

    <link href="/resources/images/twgljs-icon.png" rel="shortcut icon" type="image/png">

    <title>twgl.js - twgl cube</title>
    <style>
      body {
          margin: 0;
          font-family: monospace;
      }
      canvas {
          display: block;
          width: 100vw;
          height: 100vh;
      }
      #b {
        position: absolute;
        top: 10px;
        width: 100%;
        text-align: center;
        z-index: 2;
      }
    </style>
  </head>
  <body>
    <canvas id="c"></canvas>
    <div id="b"><a href="http://twgljs.org">twgl.js</a> - instancing</div>
  </body>
  <script id="vs" type="notjs">
uniform mat4 u_viewProjection;
uniform vec3 u_lightWorldPos;
uniform mat4 u_viewInverse;

attribute vec4 instanceColor;
attribute mat4 instanceWorld;
attribute vec4 position;
attribute vec3 normal;

varying vec4 v_position;
varying vec2 v_texCoord;
varying vec3 v_normal;
varying vec3 v_surfaceToLight;
varying vec3 v_surfaceToView;
varying vec4 v_color;

void main() {
  v_color = instanceColor;
  vec4 worldPosition = instanceWorld * position;
  v_position = u_viewProjection * worldPosition;
  v_normal = (instanceWorld * vec4(normal, 0)).xyz;
  v_surfaceToLight = u_lightWorldPos - worldPosition.xyz;
  v_surfaceToView = u_viewInverse[3].xyz - worldPosition.xyz;
  gl_Position = v_position;
}
  </script>
  <script id="fs" type="notjs">
precision mediump float;

varying vec4 v_position;
varying vec3 v_normal;
varying vec3 v_surfaceToLight;
varying vec3 v_surfaceToView;
varying vec4 v_color;

uniform vec4 u_lightColor;
uniform vec4 u_ambient;
uniform vec4 u_specular;
uniform float u_shininess;
uniform float u_specularFactor;

vec4 lit(float l ,float h, float m) {
  return vec4(1.0,
              max(l, 0.0),
              (l > 0.0) ? pow(max(0.0, h), m) : 0.0,
              1.0);
}

void main() {
  vec4 diffuseColor = v_color;
  vec3 a_normal = normalize(v_normal);
  vec3 surfaceToLight = normalize(v_surfaceToLight);
  vec3 surfaceToView = normalize(v_surfaceToView);
  vec3 halfVector = normalize(surfaceToLight + surfaceToView);
  vec4 litR = lit(dot(a_normal, surfaceToLight),
                    dot(a_normal, halfVector), u_shininess);
  vec4 outColor = vec4((
  u_lightColor * (diffuseColor * litR.y + diffuseColor * u_ambient +
                u_specular * litR.z * u_specularFactor)).rgb,
      diffuseColor.a);
  gl_FragColor = outColor;
}
  </script>
  <script type="module">
    import * as twgl from '../dist/6.x/twgl-full.module.js';
    function main() {
      const m4 = twgl.m4;
      const gl = document.getElementById("c").getContext("webgl");
      twgl.addExtensionsToContext(gl);
      if (!gl.drawArraysInstanced || !gl.createVertexArray) {
        alert("need drawArraysInstanced and createVertexArray"); // eslint-disable-line
        return;
      }
      const programInfo = twgl.createProgramInfo(gl, ["vs", "fs"]);

      function rand(min, max) {
        if (max === undefined) {
          max = min;
          min = 0;
        }
        return min + Math.random() * (max - min);
      }

      const numInstances = 100000;
      const instanceWorlds = new Float32Array(numInstances * 16);
      const instanceColors = [];
      const r = 70;
      for (let i = 0; i < numInstances; ++i) {
        const mat = new Float32Array(instanceWorlds.buffer, i * 16 * 4, 16);
        m4.translation([rand(-r, r), rand(-r, r), rand(-r, r)], mat);
        m4.rotateZ(mat, rand(0, Math.PI * 2), mat);
        m4.rotateX(mat, rand(0, Math.PI * 2), mat);
        instanceColors.push(rand(1), rand(1), rand(1));
      }
      const arrays = twgl.primitives.createCubeVertices();
      Object.assign(arrays, {
        instanceWorld: {
          numComponents: 16,
          data: instanceWorlds,
          divisor: 1,
        },
        instanceColor: {
          numComponents: 3,
          data: instanceColors,
          divisor: 1,
        },
      });
      const bufferInfo = twgl.createBufferInfoFromArrays(gl, arrays);
      const vertexArrayInfo = twgl.createVertexArrayInfo(gl, programInfo, bufferInfo);

      const uniforms = {
        u_lightWorldPos: [1, 8, -30],
        u_lightColor: [1, 1, 1, 1],
        u_ambient: [0, 0, 0, 1],
        u_specular: [1, 1, 1, 1],
        u_shininess: 50,
        u_specularFactor: 1,
      };

      function render(time) {
        time *= 0.001;
        twgl.resizeCanvasToDisplaySize(gl.canvas);
        gl.viewport(0, 0, gl.canvas.width, gl.canvas.height);

        gl.enable(gl.DEPTH_TEST);
        gl.enable(gl.CULL_FACE);
        gl.clear(gl.COLOR_BUFFER_BIT | gl.DEPTH_BUFFER_BIT);

        const fov = 30 * Math.PI / 180;
        const aspect = gl.canvas.clientWidth / gl.canvas.clientHeight;
        const zNear = 0.5;
        const zFar = 500;
        const projection = m4.perspective(fov, aspect, zNear, zFar);
        const radius = 25;
        const speed = time * .1;
        const eye = [Math.sin(speed) * radius, Math.sin(speed * .7) * 10, Math.cos(speed) * radius];
        const target = [0, 0, 0];
        const up = [0, 1, 0];

        const camera = m4.lookAt(eye, target, up);
        const view = m4.inverse(camera);
        uniforms.u_viewProjection = m4.multiply(projection, view);
        uniforms.u_viewInverse = camera;

        gl.useProgram(programInfo.program);
        twgl.setBuffersAndAttributes(gl, programInfo, vertexArrayInfo);
        twgl.setUniforms(programInfo, uniforms);
        twgl.drawBufferInfo(gl, vertexArrayInfo, gl.TRIANGLES, vertexArrayInfo.numelements, 0, numInstances);

        // do it with drawObjectList (not you'd probably make/update the list outside the render loop
        // twgl.drawObjectList(gl, [
        //   {
        //     programInfo: programInfo,
        //     vertexArrayInfo: vertexArrayInfo,
        //     uniforms: uniforms,
        //     instanceCount: numInstances,
        //   },
        // ]);

        requestAnimationFrame(render);
      }
      requestAnimationFrame(render);
    }
    main();
  </script>
</html>