mrdoob · Mugen87 · Oct 11, 2023 · Sep 25, 2023 · Sep 25, 2023 · Sep 25, 2023
diff --git a/docs/examples/en/geometries/SDFGeometryGenerator.html b/docs/examples/en/geometries/SDFGeometryGenerator.html
@@ -0,0 +1,70 @@
+<!DOCTYPE html>
+<html lang="en">
+	<head>
+		<meta charset="utf-8" />
+		<base href="../../../" />
+		<script src="page.js"></script>
+		<link type="text/css" rel="stylesheet" href="page.css" />
+	</head>
+	<body>
+
+		<h1>[name]</h1>
+
+		<p class="desc">
+			[name] generates instances of [page:BufferGeometry] from a Signed Distance Function</br>
+            Uses <a href="https://www.npmjs.com/package/isosurface" target="_blank" > Mikola Lysenko's Isosurface</a>
+		</p>
+
+		<h2>Import</h2>
+
+		<p>
+			[name] is an add-on, and must be imported explicitly.
+			See [link:#manual/introduction/Installation Installation / Addons].
+		</p>
+
+		<code>
+			import { SDFGeometryGenerator } from 'three/addons/geometries/SDFGeometryGenerator.js';
+		</code>
+
+		<h2>Code Example</h2>
+
+		<code>
+		const generator = new SDFGeometryGenerator( renderer );
+		const sdf = 'float dist( vec3 p ){ return length(p) - 0.5; }' // glsl
+		const geometry = generator.generate( 64, sdf, 1 ); // ~> THREE.BufferGeometry
+		</code>
+
+		<h2>Examples</h2>
+
+		<p>[example:webgl_geometry_sdf geometry / sdf ]</p>
+
+		<h2>Constructor</h2>
+
+		<h3>[name]( [param:WebGLRenderer renderer] )</h3>
+
+		<p>
+			[page:WebGLRenderer renderer] -- The renderer used to render the scene. <br />
+		</p>
+
+		<h2>Methods</h2>
+
+		<h3>[method:BufferGeometry generate]( [param:Int resolution], [param:String distanceField], [param:Int bounds] )</h3>
+
+		<p>
+			<b>resolution</b> - Int [ mandatory ] Amount of 'voxels' used for triangulation. Must be power of 2. <br/>Gets heavy after 256, most machines won't be able to process over 512. Defaults to 64. 
+		</p>
+		<p>
+			<b>distanceField</b> - String [ mandatory ] String with glsl distance function. Name of function must be 'dist', with a vec3 argument. ( see code above ). Defaults to a sphere distance.
+		</p>
+		<p>
+			<b>bounds</b> - Int [ optional ] Bounds in which signed distance field will be evaluated. Defaults to 1.
+		</p>
+
+
+		<h2>Source</h2>
+
+		<p>
+			[link:https://github.com/mrdoob/three.js/blob/master/examples/jsm/geometries/SDFGeometry.js examples/jsm/geometries/SDFGeometryGenerator.js]
+		</p>
+	</body>
+</html>
diff --git a/docs/list.json b/docs/list.json
@@ -346,7 +346,8 @@
 				"ConvexGeometry": "examples/en/geometries/ConvexGeometry",
 				"DecalGeometry": "examples/en/geometries/DecalGeometry",
 				"ParametricGeometry": "examples/en/geometries/ParametricGeometry",
-				"TextGeometry": "examples/en/geometries/TextGeometry"
+				"TextGeometry": "examples/en/geometries/TextGeometry",
+				"SDFGeometryGenerator": "examples/en/geometries/SDFGeometryGenerator"
 			},
 
 			"Helpers": {

diff --git a/examples/files.json b/examples/files.json
@@ -34,6 +34,7 @@
 		"webgl_geometry_extrude_splines",
 		"webgl_geometry_minecraft",
 		"webgl_geometry_nurbs",
+		"webgl_geometry_sdf",
 		"webgl_geometry_shapes",
 		"webgl_geometry_spline_editor",
 		"webgl_geometry_teapot",

diff --git a/examples/jsm/geometries/SDFGeometryGenerator.js b/examples/jsm/geometries/SDFGeometryGenerator.js
@@ -0,0 +1,144 @@
+/**
+ * @author santiago / @glitch_life
+ * wrapper of https://www.npmjs.com/package/isosurface by https://github.com/mikolalysenko
+ *
+ * Returns BufferGeometry from SDF
+ */
+
+import {
+	BufferAttribute,
+	BufferGeometry,
+	FloatType,
+	Mesh,
+	OrthographicCamera,
+	PlaneGeometry,
+	Scene,
+	ShaderMaterial,
+	Vector2,
+	WebGLRenderTarget
+} from 'three';
+
+import { surfaceNet } from './../libs/surfaceNet.js';
+
+class SDFGeometryGenerator {
+
+	constructor( renderer ) {
+
+		this.renderer = renderer;
+
+	}
+
+	generate( res = 64, distFunc = 'float dist( vec3 p ){ return length(p) - 0.5; }', bounds = 1 ) {
+
+		let w, h;
+		if ( res == 8 ) [ w, h ] = [ 32, 16 ];
+		else if ( res == 16 ) [ w, h ] = [ 64, 64 ];
+		else if ( res == 32 ) [ w, h ] = [ 256, 128 ];
+		else if ( res == 64 ) [ w, h ] = [ 512, 512 ];
+		else if ( res == 128 ) [ w, h ] = [ 2048, 1024 ];
+		else if ( res == 256 ) [ w, h ] = [ 4096, 4096 ];
+		else if ( res == 512 ) [ w, h ] = [ 16384, 8096 ];
+		else if ( res == 1024 ) [ w, h ] = [ 32768, 32768 ];
+		else throw new Error( 'THREE.SDFGeometryGenerator: Resolution must be in range 8 < res < 1024 and must be ^2' );
+
+		const maxTexSize = this.renderer.capabilities.maxTextureSize;
+
+		if ( w > maxTexSize || h > maxTexSize ) throw new Error( 'THREE.SDFGeometryGenerator: Your device does not support this resolution ( ' + res + ' ), decrease [res] param.' );
+
+		const [ tilesX, tilesY ] = [ ( w / res ), ( h / res ) ];
+
+		const sdfCompute = `
+			varying vec2 vUv;
+			uniform float tileNum;
+			uniform float bounds;
+			[#dist#]
+			void main()	{ gl_FragColor=vec4( ( dist( vec3( vUv, tileNum ) * 2.0 * bounds - vec3( bounds ) ) < 0.00001 ) ? 1.0 : 0.0 ); }
+		`;
+
+		const sdfRT = this.computeSDF( w, h, tilesX, tilesY, bounds, sdfCompute.replace( '[#dist#]', distFunc ) );
+
+		const read = new Float32Array( w * h * 4 );
+		this.renderer.readRenderTargetPixels( sdfRT, 0, 0, w, h, read );
+		sdfRT.dispose();
+
+		//
+
+		const mesh = surfaceNet( [ res, res, res ], ( x, y, z ) => {
+
+			x = ( x + bounds ) * ( res / ( bounds * 2 ) );
+			y = ( y + bounds ) * ( res / ( bounds * 2 ) );
+			z = ( z + bounds ) * ( res / ( bounds * 2 ) );
+			let p = ( x + ( z % tilesX ) * res ) + y * w + ( Math.floor( z / tilesX ) * res * w );
+			p *= 4;
+			return ( read[ p + 3 ] > 0 ) ? - 0.000000001 : 1;
+
+		}, [[ - bounds, - bounds, - bounds ], [ bounds, bounds, bounds ]] );
+
+		const ps = [], ids = [];
+		const geometry = new BufferGeometry();
+		mesh.positions.forEach( p => {
+
+			ps.push( p[ 0 ], p[ 1 ], p[ 2 ], 1 );
+
+		} );
+		mesh.cells.forEach( p => ids.push( p[ 0 ], p[ 1 ], p[ 2 ] ) );
+		geometry.setAttribute( 'position', new BufferAttribute( new Float32Array( ps ), 4 ) );
+		geometry.setIndex( ids );
+
+		return geometry;
+
+	}
+
+	computeSDF( width, height, tilesX, tilesY, bounds, shader ) {
+
+		const rt = new WebGLRenderTarget( width, height, { type: FloatType } );
+		const scn = new Scene();
+		const cam = new OrthographicCamera();
+		const tiles = tilesX * tilesY;
+		let currentTile = 0;
+
+		Object.assign( cam, { left: width / - 2, right: width / 2, top: height / 2, bottom: height / - 2 } ).updateProjectionMatrix();
+		cam.position.z = 2;
+
+		const tileSize = width / tilesX;
+		const geometry = new PlaneGeometry( tileSize, tileSize );
+
+		while ( currentTile ++ < tiles ) {
+
+			const c = currentTile - 1;
+			const [ px, py ] = [ ( tileSize ) / 2 + ( c % tilesX ) * ( tileSize ) - width / 2, ( tileSize ) / 2 + Math.floor( c / tilesX ) * ( tileSize ) - height / 2 ];
+			const compPlane = new Mesh( geometry, new ShaderMaterial( {
+				uniforms: {
+					res: { value: new Vector2( width, height ) },
+					tileNum: { value: c / ( tilesX * tilesY - 1 ) },
+					bounds: { value: bounds }
+				},
+				vertexShader: 'varying vec2 vUv;void main(){vUv=uv;gl_Position=projectionMatrix*modelViewMatrix*vec4(position,1.0);}',
+				fragmentShader: shader
+			} ) );
+			compPlane.position.set( px, py, 0 );
+			scn.add( compPlane );
+
+		}
+
+		this.renderer.setRenderTarget( rt );
+		this.renderer.render( scn, cam );
+		this.renderer.setRenderTarget( null );
+
+		//
+
+		geometry.dispose();
+
+		scn.traverse( function ( object ) {
+
+			if ( object.material !== undefined ) object.material.dispose();
+
+		} );
+
+		return rt;
+
+	}
+
+}
+
+export { SDFGeometryGenerator };