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webgl2_buffergeometry_attributes_integer.html
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webgl2_buffergeometry_attributes_integer.html
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<!DOCTYPE html>
<html lang="en">
<head>
<title>three.js WebGL 2 - buffergeometry - integer attributes</title>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, user-scalable=no, minimum-scale=1.0, maximum-scale=1.0">
<link type="text/css" rel="stylesheet" href="main.css">
</head>
<body>
<div id="container"></div>
<div id="info"><a href="https://threejs.org" target="_blank" rel="noopener">three.js</a> WebGL 2 - buffergeometry - integer attributes</div>
<script id="vertexShader" type="x-shader/x-vertex">
in int textureIndex;
flat out int vIndex; // "flat" indicates that the value will not be interpolated (required for integer attributes)
out vec2 vUv;
void main() {
vIndex = textureIndex;
vUv = uv;
gl_Position = projectionMatrix * modelViewMatrix * vec4( position, 1.0 );
}
</script>
<script id="fragmentShader" type="x-shader/x-fragment">
flat in int vIndex;
in vec2 vUv;
uniform sampler2D uTextures[ 3 ];
void main() {
if ( vIndex == 0 ) gl_FragColor = texture( uTextures[ 0 ], vUv );
else if ( vIndex == 1 ) gl_FragColor = texture( uTextures[ 1 ], vUv );
else if ( vIndex == 2 ) gl_FragColor = texture( uTextures[ 2 ], vUv );
}
</script>
<script type="module">
import * as THREE from '../build/three.module.js';
var camera, scene, renderer, mesh;
init();
animate();
function init() {
camera = new THREE.PerspectiveCamera( 27, window.innerWidth / window.innerHeight, 1, 3500 );
camera.position.z = 2500;
scene = new THREE.Scene();
scene.background = new THREE.Color( 0x050505 );
scene.fog = new THREE.Fog( 0x050505, 2000, 3500 );
// geometry
var triangles = 10000;
var geometry = new THREE.BufferGeometry();
var positions = [];
var uvs = [];
var textureIndices = [];
var n = 800, n2 = n / 2; // triangles spread in the cube
var d = 50, d2 = d / 2; // individual triangle size
for ( var i = 0; i < triangles; i ++ ) {
// positions
var x = Math.random() * n - n2;
var y = Math.random() * n - n2;
var z = Math.random() * n - n2;
var ax = x + Math.random() * d - d2;
var ay = y + Math.random() * d - d2;
var az = z + Math.random() * d - d2;
var bx = x + Math.random() * d - d2;
var by = y + Math.random() * d - d2;
var bz = z + Math.random() * d - d2;
var cx = x + Math.random() * d - d2;
var cy = y + Math.random() * d - d2;
var cz = z + Math.random() * d - d2;
positions.push( ax, ay, az );
positions.push( bx, by, bz );
positions.push( cx, cy, cz );
// uvs
uvs.push( 0, 0 );
uvs.push( 0.5, 1 );
uvs.push( 1, 0 );
// texture indices
var t = i % 3;
textureIndices.push( t, t, t );
}
geometry.setAttribute( 'position', new THREE.Float32BufferAttribute( positions, 3 ) );
geometry.setAttribute( 'uv', new THREE.Float32BufferAttribute( uvs, 2 ) );
geometry.setAttribute( 'textureIndex', new THREE.Int32BufferAttribute( textureIndices, 1 ) );
geometry.computeBoundingSphere();
// material
var loader = new THREE.TextureLoader();
var map1 = loader.load( 'textures/crate.gif' );
var map2 = loader.load( 'textures/floors/FloorsCheckerboard_S_Diffuse.jpg' );
var map3 = loader.load( 'textures/terrain/grasslight-big.jpg' );
var material = new THREE.ShaderMaterial( {
uniforms: {
uTextures: {
value: [ map1, map2, map3 ]
}
},
vertexShader: document.getElementById( 'vertexShader' ).textContent,
fragmentShader: document.getElementById( 'fragmentShader' ).textContent,
side: THREE.DoubleSide
} );
// mesh
mesh = new THREE.Mesh( geometry, material );
scene.add( mesh );
// renderer
renderer = new THREE.WebGLRenderer( { antialias: true } );
renderer.setSize( window.innerWidth, window.innerHeight );
document.body.appendChild( renderer.domElement );
}
function animate() {
requestAnimationFrame( animate );
var time = Date.now() * 0.001;
mesh.rotation.x = time * 0.25;
mesh.rotation.y = time * 0.5;
renderer.render( scene, camera );
}
</script>
</body>
</html>