2d:null 2e:["$","title",null,{"children":"Structure Definition | Icaro Fonseca | Observable"}] 33:T4f1,{ const renderer = new THREE.WebGLRenderer({antialias: true}); const scene = new THREE.Scene(); scene.background = new THREE.Color(0xA9CCE3); const height = 600; const aspect = width / height; const camera = new THREE.PerspectiveCamera(50); camera.up.set(0, 0, 1); scene.add(camera); const LOA = ship.structure.hull.attributes.LOA; camera.position.set(0.7 * LOA, 0.7 * LOA, 0.7 * LOA); function onWindowResize() { renderer.setSize(width, height); camera.aspect = width / height; camera.updateProjectionMatrix(); } window.addEventListener('resize', onWindowResize); const controls = new THREE.OrbitControls(camera, renderer.domElement); controls.target = new THREE.Vector3(LOA / 2, 0, 0); controls.update(); invalidation.then(() => renderer.dispose()); renderer.setSize(width, height); renderer.setPixelRatio(devicePixelRatio); scene.add(ship3D); const ambientLight = new THREE.AmbientLight(0xffffff, 0.3); const mainLight = new THREE.DirectionalLight(0xffffff, 1); mainLight.position.set(1, 1, 1); scene.add(ambientLight, mainLight); var animate = function () { requestAnimationFrame( animate ); renderer.render( scene, camera ); }; animate(); yield renderer.domElement; }34:T305e,Ship3D = {//@EliasHasle /* THREE.js Object3D constructed from Vessel.js Ship object. There are some serious limitations to this: 1. null values encountered are assumed to be either at the top or bottom of the given station. 2. The end caps and bulkheads are sometimes corrected with zeros where they should perhaps have been clipped because of null values. */ //var hMat; //global for debugging function Ship3D(ship, stlPath) { THREE.Group.call(this); this.ship = ship; let hull = ship.structure.hull; let LOA = hull.attributes.LOA; let BOA = hull.attributes.BOA; let Depth = hull.attributes.Depth; //console.log("LOA:%.1f, BOA:%.1f, Depth:%.1f",LOA,BOA,Depth); this.position.z = -ship.designState.calculationParameters.Draft_design; //Hull let stations = hull.halfBreadths.stations; let waterlines = hull.halfBreadths.waterlines; let table = hull.halfBreadths.table; //None of these are changed during correction of the geometry. console.log(stations); console.log(waterlines); console.log(table); let N = stations.length; let M = waterlines.length; //Hull side, in principle Y offsets on an XZ plane: //Even though a plane geometry is usually defined in terms of Z offsets on an XY plane, the order of the coordinates for each vertex is not so important. What is important is to get the topology right. This is ensured by working with the right order of the vertices. let hGeom = new THREE.PlaneBufferGeometry(undefined, undefined, N - 1, M - 1); let pos = hGeom.getAttribute("position"); let pa = pos.array; //loop1: //zs let c = 0; //Iterate over waterlines for (let j = 0; j < M; j++) { //loop2: //xs //iterate over stations for (let i = 0; i < N; i++) { //if (table[j][i] === null) continue;// loop1; pa[c] = stations[i]; //x //DEBUG, OK. No attempts to read outside of table /*if(typeof table[j] === "undefined") console.error("table[%d] is undefined", j); else if (typeof table[j][i] === "undefined") console.error("table[%d][%d] is undefined", j, i);*/ //y pa[c + 1] = table[j][i]; //y pa[c + 2] = waterlines[j]; //z c += 3; } } //console.error("c-pa.length = %d", c-pa.length); //OK, sets all cells //Get rid of nulls by merging their points with the closest non-null point in the same station: /*I am joining some uvs too. Then an applied texture will be cropped, not distorted, where the hull is cropped.*/ let uv = hGeom.getAttribute("uv"); let uva = uv.array; //Iterate over stations for (let i = 0; i < N; i++) { let firstNumberJ; let lastNumberJ; //Iterate over waterlines let j; for (j = 0; j < M; j++) { let y = table[j][i]; //If this condition is satisfied (number found), //the loop will be quitted //after the extra logic below: if (y !== null) { firstNumberJ = j; lastNumberJ = j; //copy vector for i,j to positions for all null cells below: let c = firstNumberJ * N + i; let x = pa[3 * c]; let y = pa[3 * c + 1]; let z = pa[3 * c + 2]; let d = c; while (firstNumberJ > 0) { firstNumberJ--; d -= N; pa[3 * d] = x; pa[3 * d + 1] = y; pa[3 * d + 2] = z; uva[2 * d] = uva[2 * c]; uva[2 * d + 1] = uva[2 * c + 1]; } break; } console.log("null encountered."); } //Continue up the hull (with same j counter), searching for upper number. This does not account for the existence of numbers above the first null encountered. for (; j < M; j++) { let y = table[j][i]; if (y === null) { console.log("null encountered."); break; } //else not null: lastNumberJ = j; } //copy vector for i,j to positions for all null cells above: let c = lastNumberJ * N + i; let x = pa[3 * c]; let y = pa[3 * c + 1]; let z = pa[3 * c + 2]; let d = c; while (lastNumberJ < M - 1) { lastNumberJ++; d += N; pa[3 * d] = x; pa[3 * d + 1] = y; pa[3 * d + 2] = z; uva[2 * d] = uva[2 * c]; uva[2 * d + 1] = uva[2 * c + 1]; } ////////// } //console.log(pa); pos.needsUpdate = true; uv.needsUpdate = true; hGeom.computeVertexNormals(); //Bow cap: let bowPlaneOffsets = hull.getStation(LOA).map(str => str / (0.5 * BOA)); //normalized let bowCapG = new THREE.PlaneBufferGeometry(undefined, undefined, 1, M - 1); pos = bowCapG.getAttribute("position"); pa = pos.array; //constant x-offset yz plane for (let j = 0; j < M; j++) { pa[3 * (2 * j)] = 1; pa[3 * (2 * j) + 1] = bowPlaneOffsets[j]; pa[3 * (2 * j) + 2] = waterlines[j]; pa[3 * (2 * j + 1)] = 1; pa[3 * (2 * j + 1) + 1] = -bowPlaneOffsets[j]; pa[3 * (2 * j + 1) + 2] = waterlines[j]; } pos.needsUpdate = true; //Aft cap: let aftPlaneOffsets = hull.getStation(0).map(str => str / (0.5 * BOA)); //normalized let aftCapG = new THREE.PlaneBufferGeometry(undefined, undefined, 1, M - 1); pos = aftCapG.getAttribute("position"); pa = pos.array; //constant x-offset yz plane for (let j = 0; j < M; j++) { pa[3 * (2 * j)] = 0; pa[3 * (2 * j) + 1] = -aftPlaneOffsets[j]; pa[3 * (2 * j) + 2] = waterlines[j]; pa[3 * (2 * j + 1)] = 0; pa[3 * (2 * j + 1) + 1] = aftPlaneOffsets[j]; pa[3 * (2 * j + 1) + 2] = waterlines[j]; } pos.needsUpdate = true; //Bottom cap: let bottomPlaneOffsets = hull.getWaterline(0).map(hw => hw / (0.5 * BOA)); //normalized let bottomCapG = new THREE.PlaneBufferGeometry(undefined, undefined, N - 1, 1); pos = bottomCapG.getAttribute("position"); pa = pos.array; //constant z-offset xy plane for (let i = 0; i < N; i++) { pa[3 * (i)] = stations[i]; pa[3 * (i) + 1] = -bottomPlaneOffsets[i]; pa[3 * (i) + 2] = 0; pa[3 * (N + i)] = stations[i]; pa[3 * (N + i) + 1] = bottomPlaneOffsets[i]; pa[3 * (N + i) + 2] = 0; } pos.needsUpdate = true; //Hull material let phong = THREE.ShaderLib.phong; let commonDecl = "uniform float wlThreshold;uniform vec3 aboveWL; uniform vec3 belowWL;\nvarying vec3 vPos;"; let hMat = new THREE.ShaderMaterial({ uniforms: THREE.UniformsUtils.merge([phong.uniforms, { wlThreshold: new THREE.Uniform(ship.designState.calculationParameters.Draft_design / Depth), aboveWL: new THREE.Uniform(new THREE.Color(0x33aa33)), belowWL: new THREE.Uniform(new THREE.Color(0xaa3333)) }]), vertexShader: commonDecl + phong.vertexShader.replace("main() {", "main() {\nvPos = position.xyz;").replace("#define PHONG", ""), fragmentShader: commonDecl + phong.fragmentShader.replace("vec4 diffuseColor = vec4( diffuse, opacity );", "vec4 diffuseColor = vec4( (vPos.z>wlThreshold)? aboveWL.rgb : belowWL.rgb, opacity );").replace("#define PHONG", ""), side: THREE.DoubleSide, lights: true, transparent: true }); hMat.uniforms.opacity.value = 0.5; let hullGroup = new THREE.Group(); let port = new THREE.Mesh(hGeom, hMat); let starboard = new THREE.Mesh(hGeom, hMat); starboard.scale.y = -1; hullGroup.add(port, starboard); //Caps: hullGroup.add(new THREE.Mesh(bowCapG, hMat)); hullGroup.add(new THREE.Mesh(aftCapG, hMat)); hullGroup.add(new THREE.Mesh(bottomCapG, hMat)); hullGroup.scale.set(LOA, 0.5 * BOA, Depth); this.hullGroup = hullGroup; this.add(hullGroup); //DEBUG, to show only hull: //return; //Decks: var decks = new THREE.Group(); let deckMat = new THREE.MeshPhongMaterial({color: 0xcccccc/*this.randomColor()*/, transparent: true, opacity: 0.2, side: THREE.DoubleSide}); //deckGeom.translate(0,0,-0.5); let ds = ship.structure.decks; let dk = Object.keys(ds); let stss = stations.map(st => LOA * st); //use scaled stations for now console.log(dk); for (let i = 0; i < dk.length; i++) { let d = ds[dk[i]]; //deck in ship structure //Will eventually use BoxBufferGeometry, but that is harder, because vertices are duplicated in the face planes. let deckGeom = new THREE.PlaneBufferGeometry(1, 1, stss.length, 1);//new THREE.BoxBufferGeometry(1,1,1,sts.length,1,1); console.log("d.zFloor=%.1f", d.zFloor); //DEBUG let zHigh = d.zFloor; let zLow = d.zFloor - d.thickness; let wlHigh = hull.getWaterline(zHigh); let wlLow = hull.getWaterline(zLow); let pos = deckGeom.getAttribute("position"); let pa = pos.array; for (let j = 0; j < stss.length + 1; j++) { let x = d.xAft + (j / stss.length) * (d.xFwd - d.xAft); let y1 = Vessel.f.linearFromArrays(stss, wlHigh, x); let y2 = Vessel.f.linearFromArrays(stss, wlLow, x); let y = Math.min(0.5 * d.breadth, y1, y2); pa[3 * j] = x; pa[3 * j + 1] = y; pa[3 * (stss.length + 1) + 3 * j] = x; pa[3 * (stss.length + 1) + 3 * j + 1] = -y; //test } pos.needsUpdate = true; //DEBUG console.log("d.xFwd=%.1f, d.xAft=%.1f, 0.5*d.breadth=%.1f", d.xFwd, d.xAft, 0.5 * d.breadth); console.log(pa); let deck = new THREE.Mesh(deckGeom, deckMat); deck.name = dk[i]; deck.position.z = d.zFloor; //deck.scale.set(d.xFwd-d.xAft, d.breadth, d.thickness); //deck.position.set(0.5*(d.xFwd+d.xAft), 0, d.zFloor); decks.add(deck); } this.decks = decks; this.add(decks); //Bulkheads: var bulkheads = new THREE.Group(); bulkheads.scale.set(1, 0.5 * BOA, Depth); let bhGeom = new THREE.BoxBufferGeometry(1, 1, 1); bhGeom.translate(0, 0, 0.5); let bhMat = new THREE.MeshPhongMaterial({color: 0xcccccc/*this.randomColor()*/, transparent: true, opacity: 0.5, side: THREE.DoubleSide}); bhGeom.translate(0.5, 0, 0); let bhs = ship.structure.bulkheads; let bhk = Object.keys(bhs); for (let i = 0; i < bhk.length; i++) { let bulkhead = new THREE.Mesh(bhGeom, bhMat); let bh = bhs[bhk[i]]; bulkhead.name = bhk[i]; bulkhead.scale.set(bh.thickness, 1, 1); bulkhead.position.set(bh.xAft, 0, 0); bulkheads.add(bulkhead); } this.bulkheads = bulkheads; this.add(bulkheads); //Objects this.materials = {}; this.stlPath = stlPath; let stlManager = new THREE.LoadingManager(); this.stlLoader = new THREE.STLLoader(stlManager); /*stlManager.onLoad = function() { createGUI(materials, deckMat); }*/ this.blocks = new THREE.Group(); this.add(this.blocks); //Default placeholder geometry this.boxGeom = new THREE.BoxBufferGeometry(1, 1, 1); this.boxGeom.translate(0, 0, 0.5); let objects = Object.values(ship.derivedObjects); for (let i = 0; i < objects.length; i++) { this.addObject(objects[i]); } //console.log("Reached end of Ship3D constructor."); } Ship3D.prototype = Object.create(THREE.Group.prototype); Object.assign(Ship3D.prototype, { constructor: Ship3D, addObject: function(object) { let mat; let name = this.stripName(object.id); if (this.materials[name] !== undefined) { mat = this.materials[name]; } else { mat = new THREE.MeshPhongMaterial({color: this.randomColor(), transparent: true, opacity: 0.5}); this.materials[name] = mat; } let bo = object.baseObject; //Position let s = this.ship.designState.getObjectState(object); let x = s.xCentre; let y = s.yCentre; let z = s.zBase; //Scale let d = bo.boxDimensions; if (bo.file3D) { let self = this; this.stlLoader.load( this.stlPath + "/" + bo.file3D, function onLoad(geometry) { //Normalize: geometry.computeBoundingBox(); let b = geometry.boundingBox; geometry.translate(-b.min.x, -b.min.y, -b.min.z); geometry.scale(1 / (b.max.x - b.min.x), 1 / (b.max.y - b.min.y), 1 / (b.max.z - b.min.z)); //Align with the same coordinate system as placeholder blocks: geometry.translate(-0.5, -0.5, 0); let m = new THREE.Mesh(geometry, mat); m.position.set(x, y, z); m.scale.set(d.length, d.breadth, d.height); self.blocks.add(m); }, undefined, function onError() { //console.warn("Specified file " + e.File + " not found. Falling back on placeholder."); let m = new THREE.Mesh(this.boxGeom, mat); m.position.set(x, y, z); m.scale.set(d.length, d.breadth, d.height); this.blocks.add(m); } ); } else { //Placeholder: let m = new THREE.Mesh(this.boxGeom, mat); m.position.set(x, y, z); m.scale.set(d.length, d.breadth, d.height); this.blocks.add(m); } }, //this function is used as a temporary hack to group similar objects by color stripName: function(s) { s = s.replace(/[0-9]/g, ""); s = s.trim(); return s; }, randomColor: function() { let r = Math.round(Math.random() * 0xff); let g = Math.round(Math.random() * 0xff); let b = Math.round(Math.random() * 0xff); return ((r << 16) | (g << 8) | b); } }); return Ship3D; }35:[] 31:{"id":"a6531f7b8663d1b3","slug":"hull-definition-and-hydrostatics","title":"Structure Definition","thumbnail":"520e599a25916430041c8250a864d1d6e98b6eca81648aad5917232940695839","access_level":"public","create_time":"$D2019-07-08T13:33:06.314Z","update_time":"$D2019-12-04T15:15:43.820Z","view_time":null,"first_public_time":"$D2019-07-08T13:34:58.478Z","fork":false,"stars":2,"starred":false,"owner":{"type":"team","id":"45fe56d5093061eb","login":"icarofonseca","name":"Icaro Fonseca","avatar_url":"https://avatars-next.observableusercontent.com/74086e355d9bde53fd85227b6dd08934b5747470968c89184341654aa47c5050","tier":"starter_2024"},"version":66,"publish_version":null,"role":null,"authored":false,"authors":[{"type":"individual","id":"e2c2510ce71e416b","login":"icarofonseca","name":"Icaro Fonseca","avatar_url":"https://avatars-next.observableusercontent.com/74086e355d9bde53fd85227b6dd08934b5747470968c89184341654aa47c5050","tier":null}],"members":[{"type":"individual","id":"e2c2510ce71e416b","login":"icarofonseca","name":"Icaro Fonseca","avatar_url":"https://avatars-next.observableusercontent.com/74086e355d9bde53fd85227b6dd08934b5747470968c89184341654aa47c5050","tier":null,"role":"editor"}],"comments":[],"custom_thumbnail":false,"trashed":false,"lapsed":null,"subscribed":null,"forks":2,"collection":{"id":"89021f70c119f9be","slug":"vessel-js","title":"Vessel.js","owner":{"id":"45fe56d5093061eb","login":"icarofonseca","name":"Icaro Fonseca"}},"type":"notebook","body":{"title":"Structure Definition","cells":[{"id":0,"value":"md`# Structure Definition\n\nA ship structure consistis of a hull, decks and bulkheads. The specification below defines a ship with a simple prismatic hull, one deck and one bulkhead. The hull is defined with a table of offsets, and the library creates a tessellated surface to cover the points on the table. The properties waterlines and stations define the position of the sections as fractions of the LOA and Depth, respectively. The points on the table are defined for one symmetry side of the hull. The arrays on the table define the waterlines, from lowest to highets. Each point in an array is associated to one station, from last to foremost.`","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":12,"value":"spec = ({\n\t\"designState\": {\n\t\t\"calculationParameters\": {\n\t\t\t\"Draft_design\": 2\n\t\t}\n\t},\n\t\"structure\": {\n\t\t\"hull\": {\n\t\t\t\"attributes\": {\n\t\t\t\t\"LOA\": 20,\n\t\t\t\t\"BOA\": 8,\n\t\t\t\t\"Depth\": 4\n\t\t\t},\n\t\t\t\"halfBreadths\": {\n\t\t\t\t\"waterlines\": [0, 1],\n\t\t\t\t\"stations\": [0, 1],\n\t\t\t\t\"table\": [[0, 0], [1, 1]]\n\t\t\t}\n\t\t},\n\t\t\"decks\": {\n\t\t\t\"Deck_1\": {\n\t\t\t\t\"zFloor\": 3,\n\t\t\t\t\"thickness\": 0.01,\n\t\t\t\t\"xAft\": 0,\n\t\t\t\t\"xFwd\": 20,\n\t\t\t\t\"yCentre\": 0,\n\t\t\t\t\"breadth\": 8,\n\t\t\t\t\"density\": 7850\n\t\t\t}\n },\n\t\t\"bulkheads\": {\n\t\t\t\"Bulkhead_1\": {\n\t\t\t\t\"xAft\": 10,\n\t\t\t\t\"thickness\": 0.01,\n\t\t\t\t\"density\": 7850\n\t\t\t}\n }\n\t},\n\t\"baseObjects\": [],\n\t\"derivedObjects\": []\n});","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":52,"value":"md`We use the specification to create a Ship object and a Three.js object:`","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":10,"value":"ship = new Vessel.Ship(spec);","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":7,"value":"ship3D = new Ship3D(ship);","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":55,"value":"md`The 3D visualization is created with an interface built to transform the Ship object above in a Three.js render (see Snippets). The red color represents the hull surface below the design draft.`","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":5,"value":"$33","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":32,"value":"md`Snippets`","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":14,"value":"$34","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":30,"value":"md`Libraries`","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":16,"value":"THREE = {\n const THREE = window.THREE = await require(\"three@0.99.0/build/three.min.js\");\n await require(\"three@0.99.0/examples/js/controls/OrbitControls.js\").catch(() => {});\n await require(\"three@0.99.0/examples/js/loaders/STLLoader.js\").catch(() => {});\n return THREE;\n}","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":18,"value":"Vessel = require('ntnu-vessel@0.1.1/vessel.js').catch(() => window[\"Vessel\"]);","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"}],"files":"$W35","stdlib":"1","titling":"auto"}} 32:"$31:body"