import * as THREE from 'three'; const NODE_SIZE = 0.07; const LINK_SIZE = 0.02; const HYPERPLANE = 4; const r5 = Math.sqrt(5); const CELL5 = { nodes: [ {id:1, x: 1, y: 1, z: 1, w: -1 / r5 }, {id:2, x: 1, y: -1, z: -1, w: -1 / r5 }, {id:3, x: -1, y: 1, z: -1, w: -1 / r5 }, {id:4, x: -1, y: -1, z: 1, w: -1 / r5 }, {id:5, x: 0, y: 0, z: 0, w: 4 / r5 }, ], links: [ { id:1, source:1, target: 2}, { id:2, source:1, target: 3}, { id:3, source:1, target: 4}, { id:4, source:1, target: 5}, { id:5, source:2, target: 3}, { id:6, source:2, target: 4}, { id:7, source:2, target: 5}, { id:8, source:3, target: 4}, { id:9, source:3, target: 5}, { id:10, source:4, target: 5}, ] }; const CELL16 = { nodes: [ { id: 1, x: 0, y: -1, z: 0, w: 0 }, { id: 2, x: 0, y: 0, z: -1, w: 0 }, { id: 3, x: -1, y: 0, z: 0, w: 0 }, { id: 4, x: 0, y: 0, z: 1, w: 0 }, { id: 5, x: 1, y: 0, z: 0, w: 0 }, { id: 6, x: 0, y: 1, z: 0, w: 0 }, { id: 7, x: 0, y: 0, z: 0, w: -1 }, { id: 8, x: 0, y: 0, z: 0, w: 1 }, ], links: [ { id: 1, source: 1, target: 2 }, { id: 2, source: 1, target: 3 }, { id: 3, source: 1, target: 4 }, { id: 4, source: 1, target: 5 }, { id: 5, source: 2, target: 3 }, { id: 6, source: 3, target: 4 }, { id: 7, source: 4, target: 5 }, { id: 8, source: 5, target: 2 }, { id: 9, source: 2, target: 6 }, { id: 10, source: 3, target: 6 }, { id: 11, source: 4, target: 6 }, { id: 12, source: 5, target: 6 }, { id: 13, source: 1, target: 7 }, { id: 14, source: 1, target: 8 }, { id: 15, source: 2, target: 7 }, { id: 16, source: 2, target: 8 }, { id: 17, source: 3, target: 7 }, { id: 18, source: 3, target: 8 }, { id: 19, source: 4, target: 7 }, { id: 20, source: 4, target: 8 }, { id: 21, source: 5, target: 7 }, { id: 22, source: 5, target: 8 }, { id: 23, source: 6, target: 7 }, { id: 25, source: 6, target: 8 }, ] }; // hacky stuff for 4d rotations // see https://math.stackexchange.com/questions/1402362/can-rotations-in-4d-be-given-an-explicit-matrix-form#1402376 function rotZW(theta) { const ctheta = Math.cos(theta); const stheta = Math.sin(theta); return new THREE.Matrix4( ctheta, -stheta, 0, 0, stheta, ctheta, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1 ); } function rotYW(theta) { const ctheta = Math.cos(theta); const stheta = Math.sin(theta); return new THREE.Matrix4( ctheta, 0, -stheta, 0, 0, 1, 0, 0, stheta, 0, ctheta, 0, 0, 0, 0, 1, ); } function rotYZ(theta) { const ctheta = Math.cos(theta); const stheta = Math.sin(theta); return new THREE.Matrix4( ctheta, 0, 0, -stheta, 0, 1, 0, 0, 0, 0, 1, 0, stheta, 0, 0, ctheta, ); } function rotXW(theta) { const ctheta = Math.cos(theta); const stheta = Math.sin(theta); return new THREE.Matrix4( 1, 0, 0, 0, 0, ctheta, -stheta, 0, 0, stheta, ctheta, 0, 0, 0, 0, 1 ); } function rotXZ(theta) { const ctheta = Math.cos(theta); const stheta = Math.sin(theta); return new THREE.Matrix4( 1, 0, 0, 0, 0, ctheta, 0, -stheta, 0, 0, 1, 0, 0, stheta, 0, ctheta, ); } function rotXY(theta) { const ctheta = Math.cos(theta); const stheta = Math.sin(theta); return new THREE.Matrix4( 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, ctheta, -stheta, 0, 0, stheta, ctheta, ); } // putting rotation here first - it's a matrix4 function fourDtoV3(x, y, z, w, m4) { const v4 = new THREE.Vector4(x, y, z, w); v4.applyMatrix4(m4); const k = HYPERPLANE / (HYPERPLANE + v4.w); return new THREE.Vector3(v4.x * k, v4.y * k, v4.z * k); } class FourDShape extends THREE.Group { constructor(node_m, link_m, structure) { super(); this.node_m = node_m; this.link_m = link_m; this.nodes4 = structure.nodes; this.nodes3 = {}; this.links = structure.links; this.initShapes(); } makeNode(v3) { const geometry = new THREE.SphereGeometry(NODE_SIZE); const sphere = new THREE.Mesh(geometry, this.node_m); sphere.position.copy(v3); this.add(sphere); return sphere; } makeLink(link) { const n1 = this.nodes3[link.source].v3; const n2 = this.nodes3[link.target].v3; const length = n1.distanceTo(n2); const centre = new THREE.Vector3(); centre.lerpVectors(n1, n2, 0.5); const geometry = new THREE.CylinderGeometry(LINK_SIZE, LINK_SIZE, 1); const cyl = new THREE.Mesh(geometry, this.link_m); const edge = new THREE.Group(); edge.add(cyl); edge.position.copy(centre); edge.lookAt(n2); edge.scale.copy(new THREE.Vector3(1, length, 1)); cyl.rotation.x = Math.PI / 2.0; this.add(edge); return edge; } updateLink(link) { const n1 = this.nodes3[link.source].v3; const n2 = this.nodes3[link.target].v3; const length = n1.distanceTo(n2); const centre = new THREE.Vector3(); centre.lerpVectors(n1, n2, 0.5); link.object.position.copy(centre); link.object.lookAt(n2); link.object.scale.copy(new THREE.Vector3(1, 1, length)); } initShapes() { for( const n of this.nodes4 ) { const v3 = fourDtoV3(n.x, n.y, n.z, n.w, new THREE.Matrix4()); this.nodes3[n.id] = { v3: v3, object: this.makeNode(v3) }; } for( const l of this.links ) { l.object = this.makeLink(l); } } update(m4) { for( const n of this.nodes4 ) { const v3 = fourDtoV3(n.x, n.y, n.z, n.w, m4); this.nodes3[n.id].v3 = v3; this.nodes3[n.id].object.position.copy(v3); // could do scaling here } for( const l of this.links ) { this.updateLink(l); } } } const scene = new THREE.Scene(); const camera = new THREE.PerspectiveCamera( 75, window.innerWidth / window.innerHeight, 0.1, 1000 ); const light = new THREE.PointLight(0xffffff, 2); light.position.set(10, 10, 10); scene.add(light); const amblight = new THREE.AmbientLight(0xffffff, 0.2); scene.add(amblight); scene.background = new THREE.Color(0xdddddd); const renderer = new THREE.WebGLRenderer(); renderer.setSize( window.innerWidth, window.innerHeight ); document.body.appendChild( renderer.domElement ); const node_m = new THREE.MeshStandardMaterial( { color: 0x990044 } ); node_m.roughness = 0.2; const link_m = new THREE.MeshStandardMaterial( { color: 0xf0f0f0 } ); link_m.metalness = 0.4; link_m.roughness = 0.0; link_m.transparent = true; link_m.opacity = 0.3; const shape = new FourDShape(node_m, link_m, CELL5); scene.add(shape); camera.position.z = 4; let theta = 0; const rotation = new THREE.Matrix4(); function animate() { requestAnimationFrame( animate ); theta += 0.02; shape.update(rotXY(theta)); renderer.render( scene, camera ); } animate();