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+<!DOCTYPE html>
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+<html lang="en">
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+ <head>
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+ <title>three.js webgpu - nanite-style rasterizer</title>
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+ <meta charset="utf-8">
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+ <meta name="viewport" content="width=device-width, user-scalable=no, minimum-scale=1.0, maximum-scale=1.0">
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+ <link type="text/css" rel="stylesheet" href="example.css">
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+ </head>
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+ <body>
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+
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+ <div id="info">
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+ <a href="https://threejs.org/" target="_blank" rel="noopener" class="logo-link"></a>
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+
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+ <div class="title-wrapper">
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+ <a href="https://threejs.org/" target="_blank" rel="noopener">three.js</a><span>GPU-Driven Nanite-style Rasterizer</span>
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+ </div>
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+
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+ <small>Rendering <span id="triangleCount"></span> triangles.</small>
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+ </div>
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+
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+ <script type="importmap">
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+ {
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+ "imports": {
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+ "three": "../build/three.webgpu.js",
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+ "three/webgpu": "../build/three.webgpu.js",
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+ "three/tsl": "../build/three.tsl.js",
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+ "three/addons/": "./jsm/"
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+ }
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+ }
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+ </script>
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+
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+ <script type="module">
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+
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+ import * as THREE from 'three/webgpu';
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+ import { Fn, If, Loop, vec4, vec2, uvec4, mat4, uint, float, int, min, max, atomicMax, atomicAdd, atomicStore, atomicLoad, floor, cos, sin, dot, bool, storage, uniform, uniformArray, uv, instanceIndex, vertexIndex, distance, screenSize, time, texture, varyingProperty, sqrt } from 'three/tsl';
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+
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+ import { OrbitControls } from 'three/addons/controls/OrbitControls.js';
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+ import { TeapotGeometry } from 'three/addons/geometries/TeapotGeometry.js';
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+
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+ import { Inspector } from 'three/addons/inspector/Inspector.js';
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+
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+ import WebGPU from 'three/addons/capabilities/WebGPU.js';
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+
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+ if ( WebGPU.isAvailable() === false ) {
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+
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+ document.body.appendChild( WebGPU.getErrorMessage() );
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+
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+ throw new Error( 'No WebGPU support' );
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+
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+ }
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+
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+ let camera, renderer, controls;
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+ let computeRasterize, computeClear, computeFrustum, computeDispatch, computeHWArgs;
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+ let quadMesh, hwScene, hwMesh;
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+ let cameraPos, projScreenMatrixUniform, frustumPlanesUniform;
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+ let cotHalfFovUniform, pixelErrorThresholdUniform, maxRasterSizeUniform;
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+ let workQueueCountAtomic, workQueueCountRead, dispatchBuffer, workQueueBuffer, chunkBoundsBuffer;
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+ let instanceWorldBuffer, instanceMvpBuffer;
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+ let instanceWorldAttr, instanceMvpAttr;
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+ let hwDrawBuffer;
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+ let timeScale;
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+
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+ let screenTriAttr, screenTriAtomic, screenTriRead;
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+ let screenInstAttr, screenInstBuffer, screenInstRead;
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+ let maxPixels;
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+
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+ const rows = 400;
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+ const cols = 400;
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+ const instanceCount = rows * cols;
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+
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+ const MAX_RASTER_SIZE = 16;
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+ const options = { Mode: 'Meshlet Debug', Rasterizer: 'Both' };
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+
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+ // Buffer visibility packaging configuration
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+ const TRIANGLE_INDEX_BITS = 14; // Bits allocated for triangle index (2^14 = 16384 max triangles)
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+ const TRIANGLE_INDEX_MASK = 0x3FFF; // Bitmask to extract triangle index (14 bits)
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+ const DEPTH_PRECISION_MAX = 4294967295.0; // Maximum value of the 32-bit depth (2^32 - 1)
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+
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+ const background = new THREE.Color( .1, .1, .1 );
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+
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+ init();
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+
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+ async function init() {
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+
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+ renderer = new THREE.WebGPURenderer();
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+ renderer.setPixelRatio( window.devicePixelRatio );
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+ renderer.setSize( window.innerWidth, window.innerHeight );
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+ renderer.setAnimationLoop( animate );
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+ renderer.inspector = new Inspector();
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+ document.body.appendChild( renderer.domElement );
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+
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+ await renderer.init();
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+
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+ camera = new THREE.PerspectiveCamera( 50, window.innerWidth / window.innerHeight, .25, 1000000 );
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+ camera.position.set( 0, 15, 50 );
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+
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+ controls = new OrbitControls( camera, renderer.domElement );
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+ controls.target.y = - 1.5;
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+ controls.enableDamping = true;
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+ controls.zoomSpeed = .5;
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+ controls.maxDistance = 1000;
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+ controls.maxPolarAngle = Math.PI / 2;
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+
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+ // Generate LOD Geometries
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+ const lods = [
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+ { geometry: new TeapotGeometry( 1, 10 ), error: 0.0 },
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+ { geometry: new TeapotGeometry( 1, 8 ), error: 0.005 },
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+ { geometry: new TeapotGeometry( 1, 6 ), error: 0.015 },
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+ { geometry: new TeapotGeometry( 1, 5 ), error: 0.03 },
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+ { geometry: new TeapotGeometry( 1, 4 ), error: 0.06 },
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+ { geometry: new TeapotGeometry( 1, 3 ), error: 0.1 },
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+ { geometry: new TeapotGeometry( 1, 2 ), error: 0.2 }
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+ ];
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+
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+ let totalVertices = 0;
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+ let totalIndices = 0;
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+
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+ for ( const lod of lods ) {
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+
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+ const geom = lod.geometry;
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+ const pos = geom.attributes.position;
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+ const uvs = geom.attributes.uv;
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+ const idx = geom.index ? Array.from( geom.index.array ) : Array.from( { length: pos.count }, ( _, i ) => i );
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+
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+ lod.numVertices = pos.count;
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+ lod.numTriangles = idx.length / 3;
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+ lod.vertexOffset = totalVertices;
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+ lod.indexOffset = totalIndices;
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+ lod.positions = pos;
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+ lod.uvs = uvs;
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+ lod.indices = idx;
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+
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+ totalVertices += pos.count;
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+ totalIndices += idx.length;
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+
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+ }
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+
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+ const maxTrianglesPerInstance = lods[ 0 ].numTriangles;
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+ const totalTriangles = rows * cols * maxTrianglesPerInstance;
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+ document.getElementById( 'triangleCount' ).innerText = new Intl.NumberFormat().format( totalTriangles );
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+
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+ const vertexArray = new Float32Array( totalVertices * 4 ); // vec4 padded
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+ const uvArray = new Float32Array( totalVertices * 2 );
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+ const indexArray = new Uint32Array( totalIndices );
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+ const meshletTriangleArray = new Uint32Array( totalIndices / 3 ); // 1 meshlet ID per triangle
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+
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+ let currentMeshletId = 1;
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+
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+ for ( const lod of lods ) {
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+
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+ for ( let i = 0; i < lod.numVertices; i ++ ) {
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+
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+ const vIdx = lod.vertexOffset + i;
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+ vertexArray[ vIdx * 4 + 0 ] = lod.positions.getX( i );
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+ vertexArray[ vIdx * 4 + 1 ] = lod.positions.getY( i );
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+ vertexArray[ vIdx * 4 + 2 ] = lod.positions.getZ( i );
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+ vertexArray[ vIdx * 4 + 3 ] = 1.0;
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+
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+ if ( lod.uvs ) {
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+
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+ uvArray[ vIdx * 2 + 0 ] = lod.uvs.getX( i );
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+ uvArray[ vIdx * 2 + 1 ] = lod.uvs.getY( i );
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+
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+ }
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+
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+ }
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+
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+ let currentTriCount = 0;
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+ for ( let i = 0; i < lod.numTriangles; i ++ ) {
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+
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+ const triIdx = ( lod.indexOffset / 3 ) + i;
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+ indexArray[ triIdx * 3 + 0 ] = lod.vertexOffset + lod.indices[ i * 3 + 0 ];
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+ indexArray[ triIdx * 3 + 1 ] = lod.vertexOffset + lod.indices[ i * 3 + 1 ];
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+ indexArray[ triIdx * 3 + 2 ] = lod.vertexOffset + lod.indices[ i * 3 + 2 ];
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+
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+ if ( currentTriCount >= 126 ) {
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+
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+ currentMeshletId ++;
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+ currentTriCount = 0;
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+
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+ }
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+
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+ meshletTriangleArray[ triIdx ] = currentMeshletId;
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+ currentTriCount ++;
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+
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+ }
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+
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+ currentMeshletId ++;
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+
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+ }
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+
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+ // Precompute Bounding Spheres for each 64-triangle Chunk (Cluster)
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+ let totalChunks = 0;
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+ for ( const lod of lods ) {
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+
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+ lod.numChunks = Math.ceil( lod.numTriangles / 64 );
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+ lod.chunkStart = totalChunks;
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+ totalChunks += lod.numChunks;
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+
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+ }
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+
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+ const chunkBoundsData = new Float32Array( totalChunks * 4 ); // vec4: cx, cy, cz, radius
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+ let currentChunkId = 0;
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+
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+ for ( const lod of lods ) {
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+
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+ const positions = lod.positions;
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+ const indices = lod.indices;
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+
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+ for ( let c = 0; c < lod.numChunks; c ++ ) {
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+
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+ const startTri = c * 64;
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+ const endTri = Math.min( startTri + 64, lod.numTriangles );
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+
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+ // 1. Calculate Center
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+ let cx = 0, cy = 0, cz = 0;
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+ const vertCount = ( endTri - startTri ) * 3;
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+ for ( let t = startTri; t < endTri; t ++ ) {
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+
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+ for ( let v = 0; v < 3; v ++ ) {
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+
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+ const idx = indices[ t * 3 + v ];
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+ cx += positions.getX( idx );
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+ cy += positions.getY( idx );
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+ cz += positions.getZ( idx );
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+
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+ }
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+
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+ }
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+
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+ cx /= vertCount;
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+ cy /= vertCount;
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+ cz /= vertCount;
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+
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+ // 2. Calculate Radius
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+ let maxDistSq = 0;
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+ for ( let t = startTri; t < endTri; t ++ ) {
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+
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+ for ( let v = 0; v < 3; v ++ ) {
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+
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+ const idx = indices[ t * 3 + v ];
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+ const dx = positions.getX( idx ) - cx;
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+ const dy = positions.getY( idx ) - cy;
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+ const dz = positions.getZ( idx ) - cz;
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+ const distSq = dx * dx + dy * dy + dz * dz;
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+ if ( distSq > maxDistSq ) maxDistSq = distSq;
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+
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+ }
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+
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+ }
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+
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+ const radius = Math.sqrt( maxDistSq );
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+
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+ chunkBoundsData[ currentChunkId * 4 + 0 ] = cx;
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+ chunkBoundsData[ currentChunkId * 4 + 1 ] = cy;
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+ chunkBoundsData[ currentChunkId * 4 + 2 ] = cz;
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+ chunkBoundsData[ currentChunkId * 4 + 3 ] = radius;
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+ currentChunkId ++;
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+
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+ }
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+
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+ }
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+
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+ // Upload LOD offsets to GPU (uvec4: triangleStart, numTriangles, chunkStart, 0)
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+ const lodOffsetsData = new Uint32Array( lods.length * 4 );
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+ for ( let i = 0; i < lods.length; i ++ ) {
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+
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+ lodOffsetsData[ i * 4 + 0 ] = lods[ i ].indexOffset / 3;
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+ lodOffsetsData[ i * 4 + 1 ] = lods[ i ].numTriangles;
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+ lodOffsetsData[ i * 4 + 2 ] = lods[ i ].chunkStart;
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+
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+ }
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+
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+ const lodOffsetsBuffer = storage( new THREE.StorageBufferAttribute( lodOffsetsData, 4 ), 'uvec4', lods.length ).toReadOnly();
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+ chunkBoundsBuffer = storage( new THREE.StorageBufferAttribute( chunkBoundsData, 4 ), 'vec4', totalChunks ).toReadOnly();
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+
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+ // Storage Buffers
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+ const vertexBuffer = storage( new THREE.StorageBufferAttribute( vertexArray, 4 ), 'vec4', totalVertices ).toReadOnly();
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+ const uvBuffer = storage( new THREE.StorageBufferAttribute( uvArray, 2 ), 'vec2', totalVertices ).toReadOnly();
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+ const indexBuffer = storage( new THREE.StorageBufferAttribute( indexArray, 1 ), 'uint', totalIndices ).toReadOnly();
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+ const meshletIdBuffer = storage( new THREE.StorageBufferAttribute( meshletTriangleArray, 1 ), 'uint', totalIndices / 3 ).toReadOnly();
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+
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+ const materialModeUniform = uniform( 0, 'uint' );
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+
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+ const textureMap = new THREE.TextureLoader().load( 'textures/uv_grid_directx.jpg' );
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+ textureMap.colorSpace = THREE.SRGBColorSpace;
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+ textureMap.wrapS = THREE.RepeatWrapping;
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+ textureMap.wrapT = THREE.RepeatWrapping;
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+
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+ timeScale = uniform( 1.0 );
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+
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+ const parameterGroup = renderer.inspector.createParameters( 'Parameters' );
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+ parameterGroup.add( options, 'Mode', { 'Meshlet Debug': 'Meshlet Debug', 'Texture': 'Texture' } ).addEventListener( 'change', ( e ) => {
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+
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+ materialModeUniform.value = e.value === 'Texture' ? 1 : 0;
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+
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+ } );
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+
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+ parameterGroup.add( options, 'Rasterizer', { 'SW Only': 'SW Only', 'HW Only': 'HW Only', 'Both': 'Both' } );
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+
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+ parameterGroup.add( timeScale, 'value', 0.0, 1.0 );
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+
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+ // Atomic visibility buffers — pack depth + payload into single u32 for race-free atomicMax
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+ // Buffer A: depth(18 high bits) | megaTriangleIndex(14 low bits) — triangle ID
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+ // Buffer B: depth(14 high bits) | instId(18 low bits) — instance ID
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+ // Since depth occupies the high bits, atomicMax picks the closest fragment AND its payload atomically
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+ createScreenBuffers();
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+
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+ const staticInstanceData = new Float32Array( instanceCount * 4 );
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+ let dataIndex = 0;
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+
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+ for ( let i = 0; i < rows; i ++ ) {
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+
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+ for ( let j = 0; j < cols; j ++ ) {
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+
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+ staticInstanceData[ dataIndex ++ ] = ( i - rows / 2 ) * 4.0;
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+ staticInstanceData[ dataIndex ++ ] = - 1;
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+ staticInstanceData[ dataIndex ++ ] = ( j - cols / 2 ) * 4.0;
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+ staticInstanceData[ dataIndex ++ ] = 1.0; // scale
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+
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+ }
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+
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+ }
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+
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+ const instanceDataBuffer = storage( new THREE.StorageBufferAttribute( staticInstanceData, 4 ), 'vec4', instanceCount );
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+
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+ const instanceWorldData = new Float32Array( instanceCount * 16 );
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+ const instanceMvpData = new Float32Array( instanceCount * 16 );
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+
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+ instanceWorldAttr = new THREE.StorageBufferAttribute( instanceWorldData, 16 );
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+ instanceMvpAttr = new THREE.StorageBufferAttribute( instanceMvpData, 16 );
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+
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+ instanceWorldBuffer = storage( instanceWorldAttr, 'mat4', instanceCount );
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+ instanceMvpBuffer = storage( instanceMvpAttr, 'mat4', instanceCount );
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+ const instanceWorldRead = storage( instanceWorldAttr, 'mat4', instanceCount ).toReadOnly();
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+
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+ const workQueueCountData = new Uint32Array( 1 );
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+ const workQueueCountAttr = new THREE.StorageBufferAttribute( workQueueCountData, 1 );
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+ workQueueCountAtomic = storage( workQueueCountAttr, 'uint', 1 ).toAtomic();
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+ workQueueCountRead = storage( workQueueCountAttr, 'uint', 1 ).toReadOnly();
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+
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+ const dispatchData = new Uint32Array( 3 );
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+ const dispatchAttr = new THREE.IndirectStorageBufferAttribute( dispatchData, 3 );
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+ dispatchBuffer = storage( dispatchAttr, 'uint', 3 );
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+
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+ // Max work items = 60000 instances * 47 chunks = 2,820,000
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+ const MAX_WORK_ITEMS = 2820000;
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+ const workQueueData = new Uint32Array( MAX_WORK_ITEMS * 4 );
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+ workQueueBuffer = storage( new THREE.StorageBufferAttribute( workQueueData, 4 ), 'uvec4', MAX_WORK_ITEMS );
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+
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+ // HW Rasterizer Buffers (for large triangles that exceed SW raster budget)
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+ const MAX_HW_TRIANGLES = 100000;
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+
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+ // HW queue: index 0 is atomic counter, indices 1..MAX store payload32
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+ const hwQueueData = new Uint32Array( MAX_HW_TRIANGLES + 1 );
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+ const hwQueueAttr = new THREE.StorageBufferAttribute( hwQueueData, 1 );
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+ const hwQueueAtomic = storage( hwQueueAttr, 'uint', MAX_HW_TRIANGLES + 1 ).toAtomic();
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+ const hwQueueRead = storage( hwQueueAttr, 'uint', MAX_HW_TRIANGLES + 1 ).toReadOnly();
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+
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+ // Draw indirect buffer: vertexCount, instanceCount, firstVertex, firstInstance
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+ const hwDrawData = new Uint32Array( 4 );
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+ const hwDrawAttr = new THREE.IndirectStorageBufferAttribute( hwDrawData, 4 );
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+ hwDrawBuffer = storage( hwDrawAttr, 'uint', 4 );
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+
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+ projScreenMatrixUniform = uniform( new THREE.Matrix4() );
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+ frustumPlanesUniform = uniformArray( [
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+ new THREE.Vector4(), new THREE.Vector4(), new THREE.Vector4(),
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+ new THREE.Vector4(), new THREE.Vector4(), new THREE.Vector4()
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+ ], 'vec4' );
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+ cameraPos = uniform( new THREE.Vector3() );
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+ cotHalfFovUniform = uniform( 1.0 );
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|
|
+ pixelErrorThresholdUniform = uniform( 4.0 );
|
|
|
+ maxRasterSizeUniform = uniform( MAX_RASTER_SIZE, 'int' ); // Max bounding box size in pixels for SW rasterizer
|
|
|
+
|
|
|
+ // Compute Clear
|
|
|
+ computeClear = Fn( () => {
|
|
|
+
|
|
|
+ atomicStore( screenTriAtomic.element( instanceIndex ), uint( 0 ) );
|
|
|
+ screenInstBuffer.element( instanceIndex ).assign( uint( 0 ) );
|
|
|
+
|
|
|
+ If( instanceIndex.equal( 0 ), () => {
|
|
|
+
|
|
|
+ atomicStore( workQueueCountAtomic.element( 0 ), uint( 0 ) );
|
|
|
+ atomicStore( hwQueueAtomic.element( 0 ), uint( 0 ) );
|
|
|
+
|
|
|
+ } );
|
|
|
+
|
|
|
+ } )().compute( maxPixels, [ 256 ] ).setName( 'Compute Clear' );
|
|
|
+
|
|
|
+ // Compute Frustum (GPU Culling, LOD & Work Allocation)
|
|
|
+ computeFrustum = Fn( () => {
|
|
|
+
|
|
|
+ const data = instanceDataBuffer.element( instanceIndex );
|
|
|
+ const pos = data.xyz;
|
|
|
+ const scale = data.w;
|
|
|
+ const i = float( instanceIndex );
|
|
|
+
|
|
|
+ // Rotation
|
|
|
+ const rotY = time.mul( timeScale ).add( i );
|
|
|
+ const c = cos( rotY );
|
|
|
+ const s = sin( rotY );
|
|
|
+
|
|
|
+ // Compose MatrixWorld
|
|
|
+ const matrixWorld = mat4(
|
|
|
+ vec4( c.mul( scale ), 0.0, s.mul( scale ), 0.0 ),
|
|
|
+ vec4( 0.0, scale, 0.0, 0.0 ),
|
|
|
+ vec4( s.negate().mul( scale ), 0.0, c.mul( scale ), 0.0 ),
|
|
|
+ vec4( pos, 1.0 )
|
|
|
+ );
|
|
|
+
|
|
|
+ const visible = bool( true ).toVar();
|
|
|
+ const radius = scale.mul( 2.0 ); // bounding sphere radius
|
|
|
+
|
|
|
+ // Frustum culling using the 6 extracted world-space planes
|
|
|
+ Loop( { start: 0, end: 6 }, ( { i: planeIndex } ) => {
|
|
|
+
|
|
|
+ const plane = frustumPlanesUniform.element( planeIndex );
|
|
|
+ const dist = dot( plane.xyz, pos ).add( plane.w );
|
|
|
+
|
|
|
+ If( dist.lessThan( radius.negate() ), () => {
|
|
|
+
|
|
|
+ visible.assign( false );
|
|
|
+
|
|
|
+ } );
|
|
|
+
|
|
|
+ } );
|
|
|
+
|
|
|
+ If( visible, () => {
|
|
|
+
|
|
|
+ const distToCamera = distance( cameraPos, pos );
|
|
|
+
|
|
|
+ // Precompute projection factor once (Screen-Space Projected Error)
|
|
|
+ // pixelError = cotHalfFov * errorWorld / dist * screenH / 2
|
|
|
+ const pixelFactor = cotHalfFovUniform.div( max( 0.01, distToCamera ) ).mul( float( screenSize.y ) ).div( 2.0 );
|
|
|
+
|
|
|
+ const lodLevel = uint( 0 ).toVar();
|
|
|
+
|
|
|
+ let lodSelection = null;
|
|
|
+ for ( let i = lods.length - 1; i > 0; i -- ) {
|
|
|
+
|
|
|
+ const checkLod = float( lods[ i ].error ).mul( scale ).mul( pixelFactor ).lessThanEqual( pixelErrorThresholdUniform );
|
|
|
+
|
|
|
+ if ( lodSelection === null ) {
|
|
|
+
|
|
|
+ lodSelection = If( checkLod, () => {
|
|
|
+
|
|
|
+ lodLevel.assign( i );
|
|
|
+
|
|
|
+ } );
|
|
|
+
|
|
|
+ } else {
|
|
|
+
|
|
|
+ lodSelection = lodSelection.ElseIf( checkLod, () => {
|
|
|
+
|
|
|
+ lodLevel.assign( i );
|
|
|
+
|
|
|
+ } );
|
|
|
+
|
|
|
+ }
|
|
|
+
|
|
|
+ }
|
|
|
+
|
|
|
+ const lodData = lodOffsetsBuffer.element( lodLevel );
|
|
|
+ const lodTriStart = lodData.x;
|
|
|
+ const lodNumTriangles = lodData.y;
|
|
|
+ const lodChunkStart = lodData.z;
|
|
|
+
|
|
|
+ // Calculate Work Items (64 triangles per item)
|
|
|
+ const workItems = lodNumTriangles.add( 63 ).div( 64 );
|
|
|
+
|
|
|
+ // Evaluate each Chunk (Cluster)
|
|
|
+ Loop( { name: 'cIdx', type: 'uint', start: uint( 0 ), end: workItems, condition: '<' }, ( { cIdx: chunkIndex } ) => {
|
|
|
+
|
|
|
+ const globalChunkId = lodChunkStart.add( uint( chunkIndex ) );
|
|
|
+ const chunkBounds = chunkBoundsBuffer.element( globalChunkId );
|
|
|
+ const chunkCenterLocal = chunkBounds.xyz;
|
|
|
+ const chunkRadiusLocal = chunkBounds.w;
|
|
|
+
|
|
|
+ // Transform chunk bounding sphere to world space and store as var to prevent inlining
|
|
|
+ const chunkCenterWorld = matrixWorld.mul( vec4( chunkCenterLocal, 1.0 ) ).xyz.toVar();
|
|
|
+ const chunkRadiusWorld = chunkRadiusLocal.mul( scale ).toVar();
|
|
|
+
|
|
|
+ const chunkVisible = bool( true ).toVar();
|
|
|
+
|
|
|
+ // Frustum cull the chunk
|
|
|
+ Loop( { name: 'pIdx', start: 0, end: 6 }, ( { pIdx: planeIndex } ) => {
|
|
|
+
|
|
|
+ const plane = frustumPlanesUniform.element( planeIndex );
|
|
|
+ const chunkDist = dot( plane.xyz, chunkCenterWorld ).add( plane.w );
|
|
|
+
|
|
|
+ If( chunkDist.lessThan( chunkRadiusWorld.negate() ), () => {
|
|
|
+
|
|
|
+ chunkVisible.assign( false );
|
|
|
+
|
|
|
+ } );
|
|
|
+
|
|
|
+ } );
|
|
|
+
|
|
|
+ If( chunkVisible, () => {
|
|
|
+
|
|
|
+ const itemIndex = atomicAdd( workQueueCountAtomic.element( 0 ), 1 );
|
|
|
+
|
|
|
+ // uvec4( instanceIndex, triangleStart, lodNumTriangles, chunkIndex )
|
|
|
+ workQueueBuffer.element( itemIndex ).assign(
|
|
|
+ uvec4( instanceIndex, lodTriStart, lodNumTriangles, uint( chunkIndex ) )
|
|
|
+ );
|
|
|
+
|
|
|
+ } );
|
|
|
+
|
|
|
+ } );
|
|
|
+
|
|
|
+ // Store transform for this instance
|
|
|
+ instanceWorldBuffer.element( instanceIndex ).assign( matrixWorld );
|
|
|
+ instanceMvpBuffer.element( instanceIndex ).assign( projScreenMatrixUniform.mul( matrixWorld ) );
|
|
|
+
|
|
|
+ } );
|
|
|
+
|
|
|
+ } )().compute( instanceCount ).setName( 'Compute Frustum' );
|
|
|
+
|
|
|
+ // Compute Dispatch (Indirect arguments)
|
|
|
+ computeDispatch = Fn( () => {
|
|
|
+
|
|
|
+ const totalWorkgroups = workQueueCountRead.element( 0 );
|
|
|
+
|
|
|
+ const maxDim = uint( 65535 );
|
|
|
+
|
|
|
+ // Split totalWorkgroups into 2D dispatch if it exceeds 65535
|
|
|
+ const dispatchX = min( totalWorkgroups, maxDim );
|
|
|
+ const dispatchY = totalWorkgroups.add( maxDim ).sub( 1 ).div( maxDim );
|
|
|
+
|
|
|
+ dispatchBuffer.element( 0 ).assign( dispatchX );
|
|
|
+ dispatchBuffer.element( 1 ).assign( dispatchY );
|
|
|
+ dispatchBuffer.element( 2 ).assign( 1 );
|
|
|
+
|
|
|
+ } )().compute( 1 ).setName( 'Compute Dispatch' );
|
|
|
+
|
|
|
+ // Edge function for barycentric coordinates
|
|
|
+ const edgeFunction = Fn( ( [ a, b, c ] ) => {
|
|
|
+
|
|
|
+ // (c.y - a.y) * (b.x - a.x) - (c.x - a.x) * (b.y - a.y)
|
|
|
+ return c.y.sub( a.y ).mul( b.x.sub( a.x ) ).sub( c.x.sub( a.x ).mul( b.y.sub( a.y ) ) );
|
|
|
+
|
|
|
+ } );
|
|
|
+
|
|
|
+ // Compute Rasterizer
|
|
|
+ computeRasterize = Fn( () => {
|
|
|
+
|
|
|
+ const totalWorkgroups = workQueueCountRead.element( 0 );
|
|
|
+ const totalThreads = totalWorkgroups.mul( 64 );
|
|
|
+
|
|
|
+ If( instanceIndex.lessThan( totalThreads ), () => {
|
|
|
+
|
|
|
+ const workItemId = instanceIndex.div( 64 );
|
|
|
+ const localTriangleIndex = instanceIndex.mod( 64 );
|
|
|
+
|
|
|
+ const workItem = workQueueBuffer.element( workItemId );
|
|
|
+ const instId = workItem.x;
|
|
|
+ const lodTriStart = workItem.y;
|
|
|
+ const lodNumTriangles = workItem.z;
|
|
|
+ const chunkIndex = workItem.w;
|
|
|
+
|
|
|
+ const globalTriangleIndex = chunkIndex.mul( 64 ).add( localTriangleIndex );
|
|
|
+
|
|
|
+ If( globalTriangleIndex.lessThan( lodNumTriangles ), () => {
|
|
|
+
|
|
|
+ const megaTriangleIndex = lodTriStart.add( globalTriangleIndex );
|
|
|
+ const indexOffset = megaTriangleIndex.mul( 3 );
|
|
|
+
|
|
|
+ const i0 = indexBuffer.element( indexOffset );
|
|
|
+ const i1 = indexBuffer.element( indexOffset.add( 1 ) );
|
|
|
+ const i2 = indexBuffer.element( indexOffset.add( 2 ) );
|
|
|
+
|
|
|
+ const v0 = vertexBuffer.element( i0 );
|
|
|
+ const v1 = vertexBuffer.element( i1 );
|
|
|
+ const v2 = vertexBuffer.element( i2 );
|
|
|
+
|
|
|
+ const instMvpMatrix = instanceMvpBuffer.element( instId );
|
|
|
+
|
|
|
+ // MVP
|
|
|
+ const p0 = instMvpMatrix.mul( v0 );
|
|
|
+ const p1 = instMvpMatrix.mul( v1 );
|
|
|
+ const p2 = instMvpMatrix.mul( v2 );
|
|
|
+
|
|
|
+ // Near plane clipping
|
|
|
+ // If( p0.w.greaterThan( 0.5 ).and( p1.w.greaterThan( 0.5 ) ).and( p2.w.greaterThan( 0.5 ) ), () => {
|
|
|
+ If( p0.w.greaterThan( 0.0 ).and( p1.w.greaterThan( 0.0 ) ).and( p2.w.greaterThan( 0.0 ) ), () => {
|
|
|
+
|
|
|
+ const ndc0 = p0.xyz.div( p0.w );
|
|
|
+ const ndc1 = p1.xyz.div( p1.w );
|
|
|
+ const ndc2 = p2.xyz.div( p2.w );
|
|
|
+
|
|
|
+ // Early Backface Culling in NDC
|
|
|
+ const areaNdc = edgeFunction( ndc0, ndc1, ndc2 );
|
|
|
+
|
|
|
+ If( areaNdc.greaterThan( 0.0 ), () => {
|
|
|
+
|
|
|
+ // NDC guard: skip triangles entirely outside clip volume
|
|
|
+ const ndcMinX = min( ndc0.x, min( ndc1.x, ndc2.x ) );
|
|
|
+ const ndcMaxX = max( ndc0.x, max( ndc1.x, ndc2.x ) );
|
|
|
+ const ndcMinY = min( ndc0.y, min( ndc1.y, ndc2.y ) );
|
|
|
+ const ndcMaxY = max( ndc0.y, max( ndc1.y, ndc2.y ) );
|
|
|
+
|
|
|
+ If( ndcMaxX.greaterThan( - 1.0 ).and( ndcMinX.lessThan( 1.0 ) ).and( ndcMaxY.greaterThan( - 1.0 ) ).and( ndcMinY.lessThan( 1.0 ) ), () => {
|
|
|
+
|
|
|
+ // Map to screen coordinates
|
|
|
+ const w = screenSize.x;
|
|
|
+ const h = screenSize.y;
|
|
|
+ const s0 = ndc0.xy.add( 1.0 ).mul( 0.5 ).mul( vec2( w, h ) );
|
|
|
+ const s1 = ndc1.xy.add( 1.0 ).mul( 0.5 ).mul( vec2( w, h ) );
|
|
|
+ const s2 = ndc2.xy.add( 1.0 ).mul( 0.5 ).mul( vec2( w, h ) );
|
|
|
+
|
|
|
+ // Bounding Box
|
|
|
+ const minX = max( 0.0, min( s0.x, min( s1.x, s2.x ) ) );
|
|
|
+ const maxX = min( w.sub( 1.0 ), max( s0.x, max( s1.x, s2.x ) ) );
|
|
|
+ const minY = max( 0.0, min( s0.y, min( s1.y, s2.y ) ) );
|
|
|
+ const maxY = min( h.sub( 1.0 ), max( s0.y, max( s1.y, s2.y ) ) );
|
|
|
+
|
|
|
+ const startX = int( floor( minX ) );
|
|
|
+ const endX = int( floor( maxX ) );
|
|
|
+ const startY = int( floor( minY ) );
|
|
|
+ const endY = int( floor( maxY ) );
|
|
|
+
|
|
|
+ // Big triangle guard: skip triangles larger than maxRasterSize
|
|
|
+ // This is the key performance safeguard — software rasterizers
|
|
|
+ // should only handle small triangles. Large triangles cause O(n²)
|
|
|
+ // pixel iteration per thread, which kills performance when close.
|
|
|
+ const bbWidth = endX.sub( startX );
|
|
|
+ const bbHeight = endY.sub( startY );
|
|
|
+
|
|
|
+ // Compute payload32 for HW path (full precision)
|
|
|
+ // payload32: instId (18 bits) | megaTriangleIndex (14 bits)
|
|
|
+ const payload32 = instId.shiftLeft( TRIANGLE_INDEX_BITS ).bitOr( megaTriangleIndex.bitAnd( TRIANGLE_INDEX_MASK ) );
|
|
|
+
|
|
|
+ // Sub-pixel / Valid bounds rejection + big triangle guard
|
|
|
+ If( startX.lessThanEqual( endX ).and( startY.lessThanEqual( endY ) ).and( bbWidth.lessThanEqual( maxRasterSizeUniform ) ).and( bbHeight.lessThanEqual( maxRasterSizeUniform ) ), () => {
|
|
|
+
|
|
|
+ const area = edgeFunction( s0, s1, s2 );
|
|
|
+
|
|
|
+ const stepX_w0 = s1.y.sub( s2.y );
|
|
|
+ const stepY_w0 = s2.x.sub( s1.x );
|
|
|
+
|
|
|
+ const stepX_w1 = s2.y.sub( s0.y );
|
|
|
+ const stepY_w1 = s0.x.sub( s2.x );
|
|
|
+
|
|
|
+ const stepX_w2 = s0.y.sub( s1.y );
|
|
|
+ const stepY_w2 = s1.x.sub( s0.x );
|
|
|
+
|
|
|
+ // Top-Left rule check for each edge to guarantee watertightness
|
|
|
+ const isTopLeft0 = stepX_w0.lessThan( 0.0 ).or( stepX_w0.equal( 0.0 ).and( stepY_w0.greaterThan( 0.0 ) ) );
|
|
|
+ const isTopLeft1 = stepX_w1.lessThan( 0.0 ).or( stepX_w1.equal( 0.0 ).and( stepY_w1.greaterThan( 0.0 ) ) );
|
|
|
+ const isTopLeft2 = stepX_w2.lessThan( 0.0 ).or( stepX_w2.equal( 0.0 ).and( stepY_w2.greaterThan( 0.0 ) ) );
|
|
|
+
|
|
|
+ const bias0 = isTopLeft0.select( 0.0, - 1e-5 );
|
|
|
+ const bias1 = isTopLeft1.select( 0.0, - 1e-5 );
|
|
|
+ const bias2 = isTopLeft2.select( 0.0, - 1e-5 );
|
|
|
+
|
|
|
+ const pStart = vec2( float( startX ).add( 0.5 ), float( startY ).add( 0.5 ) );
|
|
|
+
|
|
|
+ const row_w0 = edgeFunction( s1, s2, pStart ).toVar();
|
|
|
+ const row_w1 = edgeFunction( s2, s0, pStart ).toVar();
|
|
|
+ const row_w2 = edgeFunction( s0, s1, pStart ).toVar();
|
|
|
+
|
|
|
+ row_w0.addAssign( bias0 );
|
|
|
+ row_w1.addAssign( bias1 );
|
|
|
+ row_w2.addAssign( bias2 );
|
|
|
+
|
|
|
+ // Incremental Z Math (ALU Optimization)
|
|
|
+ const b0_start = row_w0.div( area );
|
|
|
+ const b1_start = row_w1.div( area );
|
|
|
+ const b2_start = row_w2.div( area );
|
|
|
+ const row_z = b0_start.mul( ndc0.z ).add( b1_start.mul( ndc1.z ) ).add( b2_start.mul( ndc2.z ) ).toVar();
|
|
|
+
|
|
|
+ const stepX_z = stepX_w0.div( area ).mul( ndc0.z ).add( stepX_w1.div( area ).mul( ndc1.z ) ).add( stepX_w2.div( area ).mul( ndc2.z ) );
|
|
|
+ const stepY_z = stepY_w0.div( area ).mul( ndc0.z ).add( stepY_w1.div( area ).mul( ndc1.z ) ).add( stepY_w2.div( area ).mul( ndc2.z ) );
|
|
|
+
|
|
|
+ Loop( { name: 'y', type: 'int', start: startY, end: endY, condition: '<=' }, ( { y } ) => {
|
|
|
+
|
|
|
+ const w0 = row_w0.toVar();
|
|
|
+ const w1 = row_w1.toVar();
|
|
|
+ const w2 = row_w2.toVar();
|
|
|
+ const z = row_z.toVar();
|
|
|
+
|
|
|
+ Loop( { name: 'x', type: 'int', start: startX, end: endX, condition: '<=' }, ( { x } ) => {
|
|
|
+
|
|
|
+ If( w0.greaterThanEqual( 0.0 ).and( w1.greaterThanEqual( 0.0 ) ).and( w2.greaterThanEqual( 0.0 ) ), () => {
|
|
|
+
|
|
|
+ If( z.greaterThanEqual( 0.0 ).and( z.lessThanEqual( 1.0 ) ), () => {
|
|
|
+
|
|
|
+ // Calculate 32-bit depth value (fourth-root distribution to maximize depth precision)
|
|
|
+ const depth32 = uint( sqrt( sqrt( float( 1.0 ).sub( z ) ) ).mul( DEPTH_PRECISION_MAX ) );
|
|
|
+
|
|
|
+ const pixelIndex = uint( y ).mul( uint( screenSize.x ) ).add( uint( x ) );
|
|
|
+
|
|
|
+ // Early depth pre-check: skip atomicMax if pixel already has closer fragment
|
|
|
+ const currentDepth = atomicLoad( screenTriAtomic.element( pixelIndex ) );
|
|
|
+ If( depth32.greaterThan( currentDepth ), () => {
|
|
|
+
|
|
|
+ // Atomic depth test
|
|
|
+ const prevDepth = atomicMax( screenTriAtomic.element( pixelIndex ), depth32 );
|
|
|
+
|
|
|
+ // If we successfully wrote the closest depth, write the payload
|
|
|
+ If( depth32.greaterThan( prevDepth ), () => {
|
|
|
+
|
|
|
+ screenInstBuffer.element( pixelIndex ).assign( payload32 );
|
|
|
+
|
|
|
+ } );
|
|
|
+
|
|
|
+ } );
|
|
|
+
|
|
|
+ } );
|
|
|
+
|
|
|
+ } );
|
|
|
+
|
|
|
+ w0.addAssign( stepX_w0 );
|
|
|
+ w1.addAssign( stepX_w1 );
|
|
|
+ w2.addAssign( stepX_w2 );
|
|
|
+ z.addAssign( stepX_z );
|
|
|
+
|
|
|
+ } );
|
|
|
+
|
|
|
+ row_w0.addAssign( stepY_w0 );
|
|
|
+ row_w1.addAssign( stepY_w1 );
|
|
|
+ row_w2.addAssign( stepY_w2 );
|
|
|
+ row_z.addAssign( stepY_z );
|
|
|
+
|
|
|
+ } );
|
|
|
+
|
|
|
+ } ).Else( () => {
|
|
|
+
|
|
|
+ // Big triangle → enqueue for HW rasterization
|
|
|
+ If( startX.lessThanEqual( endX ).and( startY.lessThanEqual( endY ) ), () => {
|
|
|
+
|
|
|
+ const hwCount = atomicAdd( hwQueueAtomic.element( 0 ), 1 );
|
|
|
+ const hwSlot = hwCount.add( 1 );
|
|
|
+ atomicStore( hwQueueAtomic.element( hwSlot ), payload32 );
|
|
|
+
|
|
|
+ } );
|
|
|
+
|
|
|
+ } );
|
|
|
+
|
|
|
+ } );
|
|
|
+
|
|
|
+ } ); // End Early Backface Culling
|
|
|
+
|
|
|
+ } ); // End Near Plane Clipping
|
|
|
+
|
|
|
+ } ); // End globalTriangleIndex bounds check
|
|
|
+
|
|
|
+ } ); // End instanceIndex bounds check
|
|
|
+
|
|
|
+ } )().compute( dispatchAttr ).setName( 'Compute Rasterize' );
|
|
|
+
|
|
|
+ // Compute HW Draw Indirect Args
|
|
|
+ computeHWArgs = Fn( () => {
|
|
|
+
|
|
|
+ const hwCount = atomicLoad( hwQueueAtomic.element( 0 ) );
|
|
|
+
|
|
|
+ // Non-indexed draw: vertexCount = hwCount * 3 (3 verts per triangle)
|
|
|
+ hwDrawBuffer.element( 0 ).assign( hwCount.mul( 3 ) ); // vertexCount
|
|
|
+ hwDrawBuffer.element( 1 ).assign( uint( 1 ) ); // instanceCount
|
|
|
+ hwDrawBuffer.element( 2 ).assign( uint( 0 ) ); // firstVertex
|
|
|
+ hwDrawBuffer.element( 3 ).assign( uint( 0 ) ); // firstInstance
|
|
|
+
|
|
|
+ } )().compute( 1 ).setName( 'Compute HW Args' );
|
|
|
+
|
|
|
+ // Hash function for meshlet colors (shared between HW mesh and fullscreen quad)
|
|
|
+ const hashColor = Fn( ( [ id_in ] ) => {
|
|
|
+
|
|
|
+ let id = uint( id_in ).toVar();
|
|
|
+ id = id.mul( uint( 747796405 ) ).add( uint( 289559509 ) );
|
|
|
+ id = id.shiftRight( 16 ).bitXor( id ).mul( uint( 277803737 ) );
|
|
|
+ id = id.shiftRight( 16 ).bitXor( id );
|
|
|
+
|
|
|
+ const r = float( id.bitAnd( uint( 255 ) ) ).div( 255.0 );
|
|
|
+ const g = float( id.shiftRight( 8 ).bitAnd( uint( 255 ) ) ).div( 255.0 );
|
|
|
+ const b = float( id.shiftRight( 16 ).bitAnd( uint( 255 ) ) ).div( 255.0 );
|
|
|
+
|
|
|
+ return vec4( r.mul( 0.8 ).add( 0.2 ), g.mul( 0.8 ).add( 0.2 ), b.mul( 0.8 ).add( 0.2 ), 1.0 );
|
|
|
+
|
|
|
+ } );
|
|
|
+
|
|
|
+ // HW Rasterizer Mesh (renders big triangles via GPU hardware pipeline)
|
|
|
+ // Unlike the SW rasterizer which writes to an atomic screen buffer,
|
|
|
+ // the HW mesh renders directly with real colors and hardware depth testing.
|
|
|
+ // It renders AFTER the fullscreen quad, overlaying HW-rasterized triangles.
|
|
|
+ {
|
|
|
+
|
|
|
+ // Geometry: dummy positions, vertex count driven by indirect draw
|
|
|
+ const hwGeometry = new THREE.BufferGeometry();
|
|
|
+ hwGeometry.setAttribute( 'position', new THREE.Float32BufferAttribute( new Float32Array( MAX_HW_TRIANGLES * 3 * 3 ), 3 ) );
|
|
|
+ hwGeometry.setIndirect( hwDrawAttr );
|
|
|
+ hwGeometry.boundingSphere = new THREE.Sphere().set( new THREE.Vector3(), Infinity );
|
|
|
+
|
|
|
+ // Varying to pass payload and UVs from vertex to fragment
|
|
|
+ const vPayload = varyingProperty( 'uint', 'vPayload' );
|
|
|
+ const vUv = varyingProperty( 'vec2', 'vUv' );
|
|
|
+
|
|
|
+ const hwMaterial = new THREE.NodeMaterial();
|
|
|
+ hwMaterial.depthWrite = true;
|
|
|
+ hwMaterial.depthTest = true;
|
|
|
+
|
|
|
+ // Vertex shader: vertex pulling from HW queue
|
|
|
+ hwMaterial.positionNode = Fn( () => {
|
|
|
+
|
|
|
+ // vertexIndex: 0,1,2, 3,4,5, 6,7,8, ...
|
|
|
+ const triIndex = vertexIndex.div( 3 ); // which triangle in HW queue
|
|
|
+ const localVert = vertexIndex.mod( 3 ); // which vertex (0, 1, 2)
|
|
|
+
|
|
|
+ const payload32 = hwQueueRead.element( triIndex.add( 1 ) );
|
|
|
+ const instId = payload32.shiftRight( TRIANGLE_INDEX_BITS );
|
|
|
+ const megaTriIdx = payload32.bitAnd( TRIANGLE_INDEX_MASK );
|
|
|
+
|
|
|
+ // Fetch actual vertex index from the mega index buffer
|
|
|
+ const vertGlobalIdx = indexBuffer.element( megaTriIdx.mul( 3 ).add( localVert ) );
|
|
|
+ const v = vertexBuffer.element( vertGlobalIdx );
|
|
|
+
|
|
|
+ // Transform to world space
|
|
|
+ const worldPos = instanceWorldRead.element( instId ).mul( v );
|
|
|
+
|
|
|
+ const uvVal = uvBuffer.element( vertGlobalIdx );
|
|
|
+ vUv.assign( uvVal );
|
|
|
+
|
|
|
+ vPayload.assign( payload32 );
|
|
|
+
|
|
|
+ return worldPos.xyz;
|
|
|
+
|
|
|
+ } )();
|
|
|
+
|
|
|
+ // Fragment shader: directly output final color (no storage buffer writes)
|
|
|
+ hwMaterial.fragmentNode = Fn( () => {
|
|
|
+
|
|
|
+ const payload32 = vPayload;
|
|
|
+ const instId = payload32.shiftRight( TRIANGLE_INDEX_BITS );
|
|
|
+ const megaTriangleIndex = payload32.bitAnd( TRIANGLE_INDEX_MASK );
|
|
|
+
|
|
|
+ const outColor = vec4( 0.0 ).toVar();
|
|
|
+
|
|
|
+ If( materialModeUniform.equal( 0 ), () => {
|
|
|
+
|
|
|
+ const meshletId = meshletIdBuffer.element( megaTriangleIndex ).add( instId.mul( 1000 ) );
|
|
|
+ outColor.assign( hashColor( meshletId ) );
|
|
|
+
|
|
|
+ } ).Else( () => {
|
|
|
+
|
|
|
+ // Hardware interpolated UV!
|
|
|
+ outColor.assign( texture( textureMap, vUv ) );
|
|
|
+
|
|
|
+ } );
|
|
|
+
|
|
|
+ return outColor;
|
|
|
+
|
|
|
+ } )();
|
|
|
+
|
|
|
+ hwMesh = new THREE.Mesh( hwGeometry, hwMaterial );
|
|
|
+ hwMesh.frustumCulled = false;
|
|
|
+
|
|
|
+ hwScene = new THREE.Scene();
|
|
|
+ hwScene.add( hwMesh );
|
|
|
+
|
|
|
+ }
|
|
|
+
|
|
|
+
|
|
|
+ // Fullscreen Presentation Pass
|
|
|
+ const material = new THREE.NodeMaterial();
|
|
|
+ material.depthWrite = true;
|
|
|
+
|
|
|
+ // Shared screen-coordinate helper
|
|
|
+ const getPixelIndex = () => {
|
|
|
+
|
|
|
+ const screenX = uint( floor( uv().x.mul( screenSize.x ) ) );
|
|
|
+ const screenY = uint( floor( uv().y.oneMinus().mul( screenSize.y ) ) );
|
|
|
+ return { screenX, screenY, pixelIndex: screenY.mul( uint( screenSize.x ) ).add( screenX ) };
|
|
|
+
|
|
|
+ };
|
|
|
+
|
|
|
+ // Output depth from the SW rasterizer so HW mesh can depth test against it
|
|
|
+ material.depthNode = Fn( () => {
|
|
|
+
|
|
|
+ const { pixelIndex } = getPixelIndex();
|
|
|
+
|
|
|
+ // Read 32-bit depth from buffer
|
|
|
+ const depth32 = screenTriRead.element( pixelIndex );
|
|
|
+
|
|
|
+ // Reconstruct NDC Z from non-linear depth32 (fourth-root distribution)
|
|
|
+ const y = float( depth32 ).div( DEPTH_PRECISION_MAX );
|
|
|
+ const y2 = y.mul( y );
|
|
|
+ const v = y2.mul( y2 ); // raise to the fourth power (y^4) to get original v
|
|
|
+ return float( 1.0 ).sub( v );
|
|
|
+
|
|
|
+ } )();
|
|
|
+
|
|
|
+ material.colorNode = Fn( () => {
|
|
|
+
|
|
|
+ const { pixelIndex } = getPixelIndex();
|
|
|
+
|
|
|
+ // Single buffer read — check for background immediately (using 32-bit depth)
|
|
|
+ const depth32 = screenTriRead.element( pixelIndex );
|
|
|
+
|
|
|
+ // Background color for pixels with no geometry
|
|
|
+ const outColor = vec4( background, 1.0 ).toVar();
|
|
|
+
|
|
|
+ If( depth32.greaterThan( 0 ), () => {
|
|
|
+
|
|
|
+ // Read the single packed payload
|
|
|
+ const payload32 = screenInstRead.element( pixelIndex );
|
|
|
+ const megaTriangleIndex = payload32.bitAnd( TRIANGLE_INDEX_MASK );
|
|
|
+ const instId = payload32.shiftRight( TRIANGLE_INDEX_BITS );
|
|
|
+
|
|
|
+ // Visibility Buffer: Fetch exact vertices and UVs
|
|
|
+ const i0 = indexBuffer.element( megaTriangleIndex.mul( 3 ).add( 0 ) );
|
|
|
+ const i1 = indexBuffer.element( megaTriangleIndex.mul( 3 ).add( 1 ) );
|
|
|
+ const i2 = indexBuffer.element( megaTriangleIndex.mul( 3 ).add( 2 ) );
|
|
|
+
|
|
|
+ const v0 = vertexBuffer.element( i0 );
|
|
|
+ const v1 = vertexBuffer.element( i1 );
|
|
|
+ const v2 = vertexBuffer.element( i2 );
|
|
|
+
|
|
|
+ const t_uv0 = uvBuffer.element( i0 );
|
|
|
+ const t_uv1 = uvBuffer.element( i1 );
|
|
|
+ const t_uv2 = uvBuffer.element( i2 );
|
|
|
+
|
|
|
+ // Project Vertices to Screen Space
|
|
|
+ const matrixWorld = instanceWorldBuffer.element( instId );
|
|
|
+ const mvpMatrix = projScreenMatrixUniform.mul( matrixWorld );
|
|
|
+
|
|
|
+ const p0 = mvpMatrix.mul( v0 );
|
|
|
+ const p1 = mvpMatrix.mul( v1 );
|
|
|
+ const p2 = mvpMatrix.mul( v2 );
|
|
|
+
|
|
|
+ const ndc0 = p0.xyz.div( p0.w );
|
|
|
+ const ndc1 = p1.xyz.div( p1.w );
|
|
|
+ const ndc2 = p2.xyz.div( p2.w );
|
|
|
+
|
|
|
+ const w = screenSize.x;
|
|
|
+ const h = screenSize.y;
|
|
|
+ const s0 = ndc0.xy.add( 1.0 ).mul( 0.5 ).mul( vec2( w, h ) );
|
|
|
+ const s1 = ndc1.xy.add( 1.0 ).mul( 0.5 ).mul( vec2( w, h ) );
|
|
|
+ const s2 = ndc2.xy.add( 1.0 ).mul( 0.5 ).mul( vec2( w, h ) );
|
|
|
+
|
|
|
+ const p = vec2( uv().x.mul( screenSize.x ), uv().y.oneMinus().mul( screenSize.y ) );
|
|
|
+
|
|
|
+ // Compute Barycentrics
|
|
|
+ const area = edgeFunction( s0, s1, s2 );
|
|
|
+ const w0 = edgeFunction( s1, s2, p );
|
|
|
+ const w1 = edgeFunction( s2, s0, p );
|
|
|
+ const w2 = edgeFunction( s0, s1, p );
|
|
|
+
|
|
|
+ // Guard against division by zero for safe execution
|
|
|
+ const safeArea = area.equal( 0.0 ).select( 1.0, area );
|
|
|
+ const b0 = w0.div( safeArea );
|
|
|
+ const b1 = w1.div( safeArea );
|
|
|
+ const b2 = w2.div( safeArea );
|
|
|
+
|
|
|
+ // Perspective correct UV interpolation (32-bit floats!)
|
|
|
+ const z_inv = b0.div( p0.w ).add( b1.div( p1.w ) ).add( b2.div( p2.w ) );
|
|
|
+ const safeZInv = z_inv.equal( 0.0 ).select( 1.0, z_inv );
|
|
|
+ const b0_p = b0.div( p0.w ).div( safeZInv );
|
|
|
+ const b1_p = b1.div( p1.w ).div( safeZInv );
|
|
|
+ const b2_p = b2.div( p2.w ).div( safeZInv );
|
|
|
+
|
|
|
+ const uv_interp = t_uv0.mul( b0_p ).add( t_uv1.mul( b1_p ) ).add( t_uv2.mul( b2_p ) );
|
|
|
+
|
|
|
+ // Compute screen-space derivatives analytically (extremely clean, no helper fragment issues)
|
|
|
+ const dw0_dx = s2.y.sub( s1.y );
|
|
|
+ const dw1_dx = s0.y.sub( s2.y );
|
|
|
+ const dw2_dx = s1.y.sub( s0.y );
|
|
|
+
|
|
|
+ const dw0_dy = s1.x.sub( s2.x );
|
|
|
+ const dw1_dy = s2.x.sub( s0.x );
|
|
|
+ const dw2_dy = s0.x.sub( s1.x );
|
|
|
+
|
|
|
+ const q0 = float( 1.0 ).div( p0.w );
|
|
|
+ const q1 = float( 1.0 ).div( p1.w );
|
|
|
+ const q2 = float( 1.0 ).div( p2.w );
|
|
|
+
|
|
|
+ const sum_w_q = w0.mul( q0 ).add( w1.mul( q1 ) ).add( w2.mul( q2 ) );
|
|
|
+ const safe_sum_w_q = sum_w_q.equal( 0.0 ).select( 1.0, sum_w_q );
|
|
|
+
|
|
|
+ const dUvDx = (
|
|
|
+ dw0_dx.mul( q0 ).mul( t_uv0.sub( uv_interp ) )
|
|
|
+ .add( dw1_dx.mul( q1 ).mul( t_uv1.sub( uv_interp ) ) )
|
|
|
+ .add( dw2_dx.mul( q2 ).mul( t_uv2.sub( uv_interp ) ) )
|
|
|
+ ).div( safe_sum_w_q );
|
|
|
+
|
|
|
+ const dUvDy = (
|
|
|
+ dw0_dy.mul( q0 ).mul( t_uv0.sub( uv_interp ) )
|
|
|
+ .add( dw1_dy.mul( q1 ).mul( t_uv1.sub( uv_interp ) ) )
|
|
|
+ .add( dw2_dy.mul( q2 ).mul( t_uv2.sub( uv_interp ) ) )
|
|
|
+ ).div( safe_sum_w_q );
|
|
|
+
|
|
|
+ If( materialModeUniform.equal( 0 ), () => {
|
|
|
+
|
|
|
+ const meshletId = meshletIdBuffer.element( megaTriangleIndex ).add( instId.mul( 1000 ) );
|
|
|
+ outColor.assign( hashColor( meshletId ) );
|
|
|
+
|
|
|
+ } ).Else( () => {
|
|
|
+
|
|
|
+ outColor.assign( texture( textureMap, uv_interp ).grad( dUvDx, dUvDy ) );
|
|
|
+
|
|
|
+ } );
|
|
|
+
|
|
|
+ } );
|
|
|
+
|
|
|
+ return outColor;
|
|
|
+
|
|
|
+ } )();
|
|
|
+
|
|
|
+ quadMesh = new THREE.QuadMesh( material );
|
|
|
+
|
|
|
+ window.addEventListener( 'resize', onWindowResize );
|
|
|
+
|
|
|
+ }
|
|
|
+
|
|
|
+ function createScreenBuffers() {
|
|
|
+
|
|
|
+ const size = new THREE.Vector2();
|
|
|
+ renderer.getDrawingBufferSize( size );
|
|
|
+ const newMaxPixels = size.x * size.y;
|
|
|
+
|
|
|
+ if ( newMaxPixels === maxPixels ) return;
|
|
|
+
|
|
|
+ maxPixels = newMaxPixels;
|
|
|
+
|
|
|
+ if ( screenTriAttr ) screenTriAttr.dispose();
|
|
|
+ if ( screenInstAttr ) screenInstAttr.dispose();
|
|
|
+
|
|
|
+ const screenTriData = new Uint32Array( maxPixels );
|
|
|
+ screenTriAttr = new THREE.StorageBufferAttribute( screenTriData, 1 );
|
|
|
+
|
|
|
+ const screenInstData = new Uint32Array( maxPixels );
|
|
|
+ screenInstAttr = new THREE.StorageBufferAttribute( screenInstData, 1 );
|
|
|
+
|
|
|
+ if ( screenTriAtomic === undefined ) {
|
|
|
+
|
|
|
+ screenTriAtomic = storage( screenTriAttr, 'uint', maxPixels ).toAtomic();
|
|
|
+ screenTriRead = storage( screenTriAttr, 'uint', maxPixels ).toReadOnly();
|
|
|
+
|
|
|
+ screenInstBuffer = storage( screenInstAttr, 'uint', maxPixels );
|
|
|
+ screenInstRead = storage( screenInstAttr, 'uint', maxPixels ).toReadOnly();
|
|
|
+
|
|
|
+ } else {
|
|
|
+
|
|
|
+ screenTriAtomic.value = screenTriAttr;
|
|
|
+ screenTriAtomic.bufferCount = maxPixels;
|
|
|
+
|
|
|
+ screenTriRead.value = screenTriAttr;
|
|
|
+ screenTriRead.bufferCount = maxPixels;
|
|
|
+
|
|
|
+ screenInstBuffer.value = screenInstAttr;
|
|
|
+ screenInstBuffer.bufferCount = maxPixels;
|
|
|
+
|
|
|
+ screenInstRead.value = screenInstAttr;
|
|
|
+ screenInstRead.bufferCount = maxPixels;
|
|
|
+
|
|
|
+ computeClear.count = maxPixels;
|
|
|
+ computeClear.dispose();
|
|
|
+
|
|
|
+ computeRasterize.dispose();
|
|
|
+ computeFrustum.dispose();
|
|
|
+ computeDispatch.dispose();
|
|
|
+ computeHWArgs.dispose();
|
|
|
+
|
|
|
+ quadMesh.material.dispose();
|
|
|
+ hwMesh.material.dispose();
|
|
|
+
|
|
|
+ }
|
|
|
+
|
|
|
+ }
|
|
|
+
|
|
|
+ function onWindowResize() {
|
|
|
+
|
|
|
+ camera.aspect = window.innerWidth / window.innerHeight;
|
|
|
+ camera.updateProjectionMatrix();
|
|
|
+
|
|
|
+ renderer.setSize( window.innerWidth, window.innerHeight );
|
|
|
+
|
|
|
+ createScreenBuffers();
|
|
|
+
|
|
|
+ }
|
|
|
+
|
|
|
+ const frustum = new THREE.Frustum();
|
|
|
+ const projScreenMatrix = new THREE.Matrix4();
|
|
|
+ const cameraInverse = new THREE.Matrix4();
|
|
|
+
|
|
|
+ function animate() {
|
|
|
+
|
|
|
+ controls.update();
|
|
|
+
|
|
|
+ camera.updateMatrixWorld();
|
|
|
+
|
|
|
+ cameraInverse.copy( camera.matrixWorld ).invert();
|
|
|
+ projScreenMatrix.multiplyMatrices( camera.projectionMatrix, cameraInverse );
|
|
|
+ frustum.setFromProjectionMatrix( projScreenMatrix );
|
|
|
+
|
|
|
+ // Update GPU uniforms
|
|
|
+ projScreenMatrixUniform.value.copy( projScreenMatrix );
|
|
|
+ cameraPos.value.copy( camera.position );
|
|
|
+ cotHalfFovUniform.value = camera.projectionMatrix.elements[ 5 ];
|
|
|
+
|
|
|
+ // Pack frustum planes into the uniform array
|
|
|
+ const planes = frustum.planes;
|
|
|
+ const planesArray = frustumPlanesUniform.array;
|
|
|
+ for ( let i = 0; i < 6; i ++ ) {
|
|
|
+
|
|
|
+ const p = planes[ i ];
|
|
|
+ planesArray[ i ].set( p.normal.x, p.normal.y, p.normal.z, p.constant );
|
|
|
+
|
|
|
+ }
|
|
|
+
|
|
|
+ // Compute & Render
|
|
|
+ renderer.compute( computeClear );
|
|
|
+ renderer.compute( computeFrustum );
|
|
|
+ renderer.compute( computeDispatch );
|
|
|
+ renderer.compute( computeRasterize );
|
|
|
+ renderer.compute( computeHWArgs );
|
|
|
+
|
|
|
+ const rasterMode = options.Rasterizer;
|
|
|
+
|
|
|
+ // SW presentation (fullscreen quad reads atomic buffer)
|
|
|
+ if ( rasterMode === 'SW Only' || rasterMode === 'Both' ) {
|
|
|
+
|
|
|
+ quadMesh.render( renderer );
|
|
|
+
|
|
|
+ }
|
|
|
+
|
|
|
+ // HW mesh renders with real depth testing + colors
|
|
|
+ if ( rasterMode === 'HW Only' || rasterMode === 'Both' ) {
|
|
|
+
|
|
|
+ hwScene.background = ( rasterMode === 'HW Only' ) ? background : null;
|
|
|
+ renderer.autoClear = ( rasterMode === 'HW Only' );
|
|
|
+ renderer.render( hwScene, camera );
|
|
|
+ renderer.autoClear = true;
|
|
|
+
|
|
|
+ }
|
|
|
+
|
|
|
+ }
|
|
|
+
|
|
|
+ </script>
|
|
|
+ </body>
|
|
|
+</html>
|
sunag
