Traffic Run Game with Three.js

index.html

<div id="score">Press UP</div>

<div id="controls">
  <div id="buttons">
    <button id="accelerate">
      <svg width="30" height="30" viewBox="0 0 10 10">
        <g transform="rotate(0, 5,5)">
          <path d="M5,4 L7,6 L3,6 L5,4" />
        </g>
      </svg>
    </button>
    <button id="decelerate">
      <svg width="30" height="30" viewBox="0 0 10 10">
        <g transform="rotate(180, 5,5)">
          <path d="M5,4 L7,6 L3,6 L5,4" />
        </g>
      </svg>
    </button>
  </div>
  <div id="instructions">
    Press UP to start. Avoid collision with other vehicles by accelerating
    or decelerating with the UP and DOWN keys.
  </div>
</div>

<div id="results">
  <div class="content">
    <h1>You hit another vehicle</h1>
    <p>To reset the game press R</p>

    <a id="result-youtube" target="_blank" href="https://youtu.be/JhgBwJn1bQw">
      <div class="youtube"></div>
      <span>Learn how to build this game with Three.js on YouTube</span>
    </a>

    <p>
      Follow me
      <a href="https://hpitgroup.glitch.me/" , target="_blank">HARUN PEHLİVAN </a>
    </p>
  </div>
</div>

<a id="youtube-main" class="youtube" target="_blank" href="https://youtu.be/JhgBwJn1bQw">
  <span>Learn Three.js</span>
</a>
<div id="youtube-card">
  Learn Three.js while building this game on YouTube
</div>

script.js

/*

Three.js video tutorial explaining the source code

Youtube: https://youtu.be/JhgBwJn1bQw

In the tutorial, we go through the source code of this game. We cover, how to set up a Three.js scene with box objects, how to add lights, how to set up the camera, how to add animation and event handlers. We also add textures with HTML Canvas and learn how to draw 2D shapes in Three.js then how to turn them into extruded geometries.

Comparing to the tutorial this version has some extra features:
- trucks also pop up on the other track
- the extruded geometry also has a texture
- there are trees around the track
- shadows
- the game reacts to window resizing

Check out my YouTube channel for other game tutorials: https://www.youtube.com/channel/UCxhgW0Q5XLvIoXHAfQXg9oQ

*/

window.focus(); // Capture keys right away (by default focus is on editor)

// Pick a random value from an array
function pickRandom(array) {
  return array[Math.floor(Math.random() * array.length)];
}

// The Pythagorean theorem says that the distance between two points is
// the square root of the sum of the horizontal and vertical distance's square
function getDistance(coordinate1, coordinate2) {
  const horizontalDistance = coordinate2.x - coordinate1.x;
  const verticalDistance = coordinate2.y - coordinate1.y;
  return Math.sqrt(horizontalDistance ** 2 + verticalDistance ** 2);
}

const vehicleColors = [
  0xa52523,
  0xef2d56,
  0x0ad3ff,
  0xff9f1c /*0xa52523, 0xbdb638, 0x78b14b*/
];

const lawnGreen = "#67C240";
const trackColor = "#546E90";
const edgeColor = "#725F48";
const treeCrownColor = 0x498c2c;
const treeTrunkColor = 0x4b3f2f;

const wheelGeometry = new THREE.BoxBufferGeometry(12, 33, 12);
const wheelMaterial = new THREE.MeshLambertMaterial({ color: 0x333333 });
const treeTrunkGeometry = new THREE.BoxBufferGeometry(15, 15, 30);
const treeTrunkMaterial = new THREE.MeshLambertMaterial({
  color: treeTrunkColor
});
const treeCrownMaterial = new THREE.MeshLambertMaterial({
  color: treeCrownColor
});

const config = {
  showHitZones: false,
  shadows: true, // Use shadow
  trees: true, // Add trees to the map
  curbs: true, // Show texture on the extruded geometry
  grid: false // Show grid helper
};

let score;
const speed = 0.0017;

const playerAngleInitial = Math.PI;
let playerAngleMoved;
let accelerate = false; // Is the player accelerating
let decelerate = false; // Is the player decelerating

let otherVehicles = [];
let ready;
let lastTimestamp;

const trackRadius = 225;
const trackWidth = 45;
const innerTrackRadius = trackRadius - trackWidth;
const outerTrackRadius = trackRadius + trackWidth;

const arcAngle1 = (1 / 3) * Math.PI; // 60 degrees

const deltaY = Math.sin(arcAngle1) * innerTrackRadius;
const arcAngle2 = Math.asin(deltaY / outerTrackRadius);

const arcCenterX =
  (Math.cos(arcAngle1) * innerTrackRadius +
    Math.cos(arcAngle2) * outerTrackRadius) /
  2;

const arcAngle3 = Math.acos(arcCenterX / innerTrackRadius);

const arcAngle4 = Math.acos(arcCenterX / outerTrackRadius);

const scoreElement = document.getElementById("score");
const buttonsElement = document.getElementById("buttons");
const instructionsElement = document.getElementById("instructions");
const resultsElement = document.getElementById("results");
const accelerateButton = document.getElementById("accelerate");
const decelerateButton = document.getElementById("decelerate");
const youtubeLogo = document.getElementById("youtube-main");

setTimeout(() => {
  if (ready) instructionsElement.style.opacity = 1;
  buttonsElement.style.opacity = 1;
  youtubeLogo.style.opacity = 1;
}, 4000);

// Initialize ThreeJs
// Set up camera
const aspectRatio = window.innerWidth / window.innerHeight;
const cameraWidth = 960;
const cameraHeight = cameraWidth / aspectRatio;

const camera = new THREE.OrthographicCamera(
  cameraWidth / -2, // left
  cameraWidth / 2, // right
  cameraHeight / 2, // top
  cameraHeight / -2, // bottom
  50, // near plane
  700 // far plane
);

camera.position.set(0, -210, 300);
camera.lookAt(0, 0, 0);

const scene = new THREE.Scene();

const playerCar = Car();
scene.add(playerCar);

renderMap(cameraWidth, cameraHeight * 2); // The map height is higher because we look at the map from an angle

// Set up lights
const ambientLight = new THREE.AmbientLight(0xffffff, 0.6);
scene.add(ambientLight);

const dirLight = new THREE.DirectionalLight(0xffffff, 0.6);
dirLight.position.set(100, -300, 300);
dirLight.castShadow = true;
dirLight.shadow.mapSize.width = 1024;
dirLight.shadow.mapSize.height = 1024;
dirLight.shadow.camera.left = -400;
dirLight.shadow.camera.right = 350;
dirLight.shadow.camera.top = 400;
dirLight.shadow.camera.bottom = -300;
dirLight.shadow.camera.near = 100;
dirLight.shadow.camera.far = 800;
scene.add(dirLight);

// const cameraHelper = new THREE.CameraHelper(dirLight.shadow.camera);
// scene.add(cameraHelper);

if (config.grid) {
  const gridHelper = new THREE.GridHelper(80, 8);
  gridHelper.rotation.x = Math.PI / 2;
  scene.add(gridHelper);
}

// Set up renderer
const renderer = new THREE.WebGLRenderer({
  antialias: true,
  powerPreference: "high-performance"
});
renderer.setSize(window.innerWidth, window.innerHeight);
if (config.shadows) renderer.shadowMap.enabled = true;
document.body.appendChild(renderer.domElement);

reset();

function reset() {
  // Reset position and score
  playerAngleMoved = 0;
  score = 0;
  scoreElement.innerText = "Press UP";

  // Remove other vehicles
  otherVehicles.forEach((vehicle) => {
    // Remove the vehicle from the scene
    scene.remove(vehicle.mesh);

    // If it has hit-zone helpers then remove them as well
    if (vehicle.mesh.userData.hitZone1)
      scene.remove(vehicle.mesh.userData.hitZone1);
    if (vehicle.mesh.userData.hitZone2)
      scene.remove(vehicle.mesh.userData.hitZone2);
    if (vehicle.mesh.userData.hitZone3)
      scene.remove(vehicle.mesh.userData.hitZone3);
  });
  otherVehicles = [];

  resultsElement.style.display = "none";

  lastTimestamp = undefined;

  // Place the player's car to the starting position
  movePlayerCar(0);

  // Render the scene
  renderer.render(scene, camera);

  ready = true;
}

function startGame() {
  if (ready) {
    ready = false;
    scoreElement.innerText = 0;
    buttonsElement.style.opacity = 1;
    instructionsElement.style.opacity = 0;
    youtubeLogo.style.opacity = 1;
    renderer.setAnimationLoop(animation);
  }
}

function positionScoreElement() {
  const arcCenterXinPixels = (arcCenterX / cameraWidth) * window.innerWidth;
  scoreElement.style.cssText = `
    left: ${window.innerWidth / 2 - arcCenterXinPixels * 1.3}px;
    top: ${window.innerHeight / 2}px
  `;
}

function getLineMarkings(mapWidth, mapHeight) {
  const canvas = document.createElement("canvas");
  canvas.width = mapWidth;
  canvas.height = mapHeight;
  const context = canvas.getContext("2d");

  context.fillStyle = trackColor;
  context.fillRect(0, 0, mapWidth, mapHeight);

  context.lineWidth = 2;
  context.strokeStyle = "#E0FFFF";
  context.setLineDash([10, 14]);

  // Left circle
  context.beginPath();
  context.arc(
    mapWidth / 2 - arcCenterX,
    mapHeight / 2,
    trackRadius,
    0,
    Math.PI * 2
  );
  context.stroke();

  // Right circle
  context.beginPath();
  context.arc(
    mapWidth / 2 + arcCenterX,
    mapHeight / 2,
    trackRadius,
    0,
    Math.PI * 2
  );
  context.stroke();

  return new THREE.CanvasTexture(canvas);
}

function getCurbsTexture(mapWidth, mapHeight) {
  const canvas = document.createElement("canvas");
  canvas.width = mapWidth;
  canvas.height = mapHeight;
  const context = canvas.getContext("2d");

  context.fillStyle = lawnGreen;
  context.fillRect(0, 0, mapWidth, mapHeight);

  // Extra big
  context.lineWidth = 65;
  context.strokeStyle = "#A2FF75";
  context.beginPath();
  context.arc(
    mapWidth / 2 - arcCenterX,
    mapHeight / 2,
    innerTrackRadius,
    arcAngle1,
    -arcAngle1
  );
  context.arc(
    mapWidth / 2 + arcCenterX,
    mapHeight / 2,
    outerTrackRadius,
    Math.PI + arcAngle2,
    Math.PI - arcAngle2,
    true
  );
  context.stroke();

  context.beginPath();
  context.arc(
    mapWidth / 2 + arcCenterX,
    mapHeight / 2,
    innerTrackRadius,
    Math.PI + arcAngle1,
    Math.PI - arcAngle1
  );
  context.arc(
    mapWidth / 2 - arcCenterX,
    mapHeight / 2,
    outerTrackRadius,
    arcAngle2,
    -arcAngle2,
    true
  );
  context.stroke();

  // Extra small
  context.lineWidth = 60;
  context.strokeStyle = lawnGreen;
  context.beginPath();
  context.arc(
    mapWidth / 2 - arcCenterX,
    mapHeight / 2,
    innerTrackRadius,
    arcAngle1,
    -arcAngle1
  );
  context.arc(
    mapWidth / 2 + arcCenterX,
    mapHeight / 2,
    outerTrackRadius,
    Math.PI + arcAngle2,
    Math.PI - arcAngle2,
    true
  );
  context.arc(
    mapWidth / 2 + arcCenterX,
    mapHeight / 2,
    innerTrackRadius,
    Math.PI + arcAngle1,
    Math.PI - arcAngle1
  );
  context.arc(
    mapWidth / 2 - arcCenterX,
    mapHeight / 2,
    outerTrackRadius,
    arcAngle2,
    -arcAngle2,
    true
  );
  context.stroke();

  // Base
  context.lineWidth = 6;
  context.strokeStyle = edgeColor;

  // Outer circle left
  context.beginPath();
  context.arc(
    mapWidth / 2 - arcCenterX,
    mapHeight / 2,
    outerTrackRadius,
    0,
    Math.PI * 2
  );
  context.stroke();

  // Outer circle right
  context.beginPath();
  context.arc(
    mapWidth / 2 + arcCenterX,
    mapHeight / 2,
    outerTrackRadius,
    0,
    Math.PI * 2
  );
  context.stroke();

  // Inner circle left
  context.beginPath();
  context.arc(
    mapWidth / 2 - arcCenterX,
    mapHeight / 2,
    innerTrackRadius,
    0,
    Math.PI * 2
  );
  context.stroke();

  // Inner circle right
  context.beginPath();
  context.arc(
    mapWidth / 2 + arcCenterX,
    mapHeight / 2,
    innerTrackRadius,
    0,
    Math.PI * 2
  );
  context.stroke();

  return new THREE.CanvasTexture(canvas);
}

function getLeftIsland() {
  const islandLeft = new THREE.Shape();

  islandLeft.absarc(
    -arcCenterX,
    0,
    innerTrackRadius,
    arcAngle1,
    -arcAngle1,
    false
  );

  islandLeft.absarc(
    arcCenterX,
    0,
    outerTrackRadius,
    Math.PI + arcAngle2,
    Math.PI - arcAngle2,
    true
  );

  return islandLeft;
}

function getMiddleIsland() {
  const islandMiddle = new THREE.Shape();

  islandMiddle.absarc(
    -arcCenterX,
    0,
    innerTrackRadius,
    arcAngle3,
    -arcAngle3,
    true
  );

  islandMiddle.absarc(
    arcCenterX,
    0,
    innerTrackRadius,
    Math.PI + arcAngle3,
    Math.PI - arcAngle3,
    true
  );

  return islandMiddle;
}

function getRightIsland() {
  const islandRight = new THREE.Shape();

  islandRight.absarc(
    arcCenterX,
    0,
    innerTrackRadius,
    Math.PI - arcAngle1,
    Math.PI + arcAngle1,
    true
  );

  islandRight.absarc(
    -arcCenterX,
    0,
    outerTrackRadius,
    -arcAngle2,
    arcAngle2,
    false
  );

  return islandRight;
}

function getOuterField(mapWidth, mapHeight) {
  const field = new THREE.Shape();

  field.moveTo(-mapWidth / 2, -mapHeight / 2);
  field.lineTo(0, -mapHeight / 2);

  field.absarc(-arcCenterX, 0, outerTrackRadius, -arcAngle4, arcAngle4, true);

  field.absarc(
    arcCenterX,
    0,
    outerTrackRadius,
    Math.PI - arcAngle4,
    Math.PI + arcAngle4,
    true
  );

  field.lineTo(0, -mapHeight / 2);
  field.lineTo(mapWidth / 2, -mapHeight / 2);
  field.lineTo(mapWidth / 2, mapHeight / 2);
  field.lineTo(-mapWidth / 2, mapHeight / 2);

  return field;
}

function renderMap(mapWidth, mapHeight) {
  const lineMarkingsTexture = getLineMarkings(mapWidth, mapHeight);

  const planeGeometry = new THREE.PlaneBufferGeometry(mapWidth, mapHeight);
  const planeMaterial = new THREE.MeshLambertMaterial({
    map: lineMarkingsTexture
  });
  const plane = new THREE.Mesh(planeGeometry, planeMaterial);
  plane.receiveShadow = true;
  plane.matrixAutoUpdate = false;
  scene.add(plane);

  // Extruded geometry with curbs
  const islandLeft = getLeftIsland();
  const islandMiddle = getMiddleIsland();
  const islandRight = getRightIsland();
  const outerField = getOuterField(mapWidth, mapHeight);

  // Mapping a texture on an extruded geometry works differently than mapping it to a box
  // By default it is mapped to a 1x1 unit square, and we have to stretch it out by setting repeat
  // We also need to shift it by setting the offset to have it centered
  const curbsTexture = getCurbsTexture(mapWidth, mapHeight);
  curbsTexture.offset = new THREE.Vector2(0.5, 0.5);
  curbsTexture.repeat.set(1 / mapWidth, 1 / mapHeight);

  // An extruded geometry turns a 2D shape into 3D by giving it a depth
  const fieldGeometry = new THREE.ExtrudeBufferGeometry(
    [islandLeft, islandRight, islandMiddle, outerField],
    { depth: 6, bevelEnabled: false }
  );

  const fieldMesh = new THREE.Mesh(fieldGeometry, [
    new THREE.MeshLambertMaterial({
      // Either set a plain color or a texture depending on config
      color: !config.curbs && lawnGreen,
      map: config.curbs && curbsTexture
    }),
    new THREE.MeshLambertMaterial({ color: 0x23311c })
  ]);
  fieldMesh.receiveShadow = true;
  fieldMesh.matrixAutoUpdate = false;
  scene.add(fieldMesh);

  positionScoreElement();

  if (config.trees) {
    const tree1 = Tree();
    tree1.position.x = arcCenterX * 1.3;
    scene.add(tree1);

    const tree2 = Tree();
    tree2.position.y = arcCenterX * 1.9;
    tree2.position.x = arcCenterX * 1.3;
    scene.add(tree2);

    const tree3 = Tree();
    tree3.position.x = arcCenterX * 0.8;
    tree3.position.y = arcCenterX * 2;
    scene.add(tree3);

    const tree4 = Tree();
    tree4.position.x = arcCenterX * 1.8;
    tree4.position.y = arcCenterX * 2;
    scene.add(tree4);

    const tree5 = Tree();
    tree5.position.x = -arcCenterX * 1;
    tree5.position.y = arcCenterX * 2;
    scene.add(tree5);

    const tree6 = Tree();
    tree6.position.x = -arcCenterX * 2;
    tree6.position.y = arcCenterX * 1.8;
    scene.add(tree6);

    const tree7 = Tree();
    tree7.position.x = arcCenterX * 0.8;
    tree7.position.y = -arcCenterX * 2;
    scene.add(tree7);

    const tree8 = Tree();
    tree8.position.x = arcCenterX * 1.8;
    tree8.position.y = -arcCenterX * 2;
    scene.add(tree8);

    const tree9 = Tree();
    tree9.position.x = -arcCenterX * 1;
    tree9.position.y = -arcCenterX * 2;
    scene.add(tree9);

    const tree10 = Tree();
    tree10.position.x = -arcCenterX * 2;
    tree10.position.y = -arcCenterX * 1.8;
    scene.add(tree10);

    const tree11 = Tree();
    tree11.position.x = arcCenterX * 0.6;
    tree11.position.y = -arcCenterX * 2.3;
    scene.add(tree11);

    const tree12 = Tree();
    tree12.position.x = arcCenterX * 1.5;
    tree12.position.y = -arcCenterX * 2.4;
    scene.add(tree12);

    const tree13 = Tree();
    tree13.position.x = -arcCenterX * 0.7;
    tree13.position.y = -arcCenterX * 2.4;
    scene.add(tree13);

    const tree14 = Tree();
    tree14.position.x = -arcCenterX * 1.5;
    tree14.position.y = -arcCenterX * 1.8;
    scene.add(tree14);
  }
}

function getCarFrontTexture() {
  const canvas = document.createElement("canvas");
  canvas.width = 64;
  canvas.height = 32;
  const context = canvas.getContext("2d");

  context.fillStyle = "#ffffff";
  context.fillRect(0, 0, 64, 32);

  context.fillStyle = "#666666";
  context.fillRect(8, 8, 48, 24);

  return new THREE.CanvasTexture(canvas);
}

function getCarSideTexture() {
  const canvas = document.createElement("canvas");
  canvas.width = 128;
  canvas.height = 32;
  const context = canvas.getContext("2d");

  context.fillStyle = "#ffffff";
  context.fillRect(0, 0, 128, 32);

  context.fillStyle = "#666666";
  context.fillRect(10, 8, 38, 24);
  context.fillRect(58, 8, 60, 24);

  return new THREE.CanvasTexture(canvas);
}

function Car() {
  const car = new THREE.Group();

  const color = pickRandom(vehicleColors);

  const main = new THREE.Mesh(
    new THREE.BoxBufferGeometry(60, 30, 15),
    new THREE.MeshLambertMaterial({ color })
  );
  main.position.z = 12;
  main.castShadow = true;
  main.receiveShadow = true;
  car.add(main);

  const carFrontTexture = getCarFrontTexture();
  carFrontTexture.center = new THREE.Vector2(0.5, 0.5);
  carFrontTexture.rotation = Math.PI / 2;

  const carBackTexture = getCarFrontTexture();
  carBackTexture.center = new THREE.Vector2(0.5, 0.5);
  carBackTexture.rotation = -Math.PI / 2;

  const carLeftSideTexture = getCarSideTexture();
  carLeftSideTexture.flipY = false;

  const carRightSideTexture = getCarSideTexture();

  const cabin = new THREE.Mesh(new THREE.BoxBufferGeometry(33, 24, 12), [
    new THREE.MeshLambertMaterial({ map: carFrontTexture }),
    new THREE.MeshLambertMaterial({ map: carBackTexture }),
    new THREE.MeshLambertMaterial({ map: carLeftSideTexture }),
    new THREE.MeshLambertMaterial({ map: carRightSideTexture }),
    new THREE.MeshLambertMaterial({ color: 0xffffff }), // top
    new THREE.MeshLambertMaterial({ color: 0xffffff }) // bottom
  ]);
  cabin.position.x = -6;
  cabin.position.z = 25.5;
  cabin.castShadow = true;
  cabin.receiveShadow = true;
  car.add(cabin);

  const backWheel = new Wheel();
  backWheel.position.x = -18;
  car.add(backWheel);

  const frontWheel = new Wheel();
  frontWheel.position.x = 18;
  car.add(frontWheel);

  if (config.showHitZones) {
    car.userData.hitZone1 = HitZone();
    car.userData.hitZone2 = HitZone();
  }

  return car;
}

function getTruckFrontTexture() {
  const canvas = document.createElement("canvas");
  canvas.width = 32;
  canvas.height = 32;
  const context = canvas.getContext("2d");

  context.fillStyle = "#ffffff";
  context.fillRect(0, 0, 32, 32);

  context.fillStyle = "#666666";
  context.fillRect(0, 5, 32, 10);

  return new THREE.CanvasTexture(canvas);
}

function getTruckSideTexture() {
  const canvas = document.createElement("canvas");
  canvas.width = 32;
  canvas.height = 32;
  const context = canvas.getContext("2d");

  context.fillStyle = "#ffffff";
  context.fillRect(0, 0, 32, 32);

  context.fillStyle = "#666666";
  context.fillRect(17, 5, 15, 10);

  return new THREE.CanvasTexture(canvas);
}

function Truck() {
  const truck = new THREE.Group();
  const color = pickRandom(vehicleColors);

  const base = new THREE.Mesh(
    new THREE.BoxBufferGeometry(100, 25, 5),
    new THREE.MeshLambertMaterial({ color: 0xb4c6fc })
  );
  base.position.z = 10;
  truck.add(base);

  const cargo = new THREE.Mesh(
    new THREE.BoxBufferGeometry(75, 35, 40),
    new THREE.MeshLambertMaterial({ color: 0xffffff }) // 0xb4c6fc
  );
  cargo.position.x = -15;
  cargo.position.z = 30;
  cargo.castShadow = true;
  cargo.receiveShadow = true;
  truck.add(cargo);

  const truckFrontTexture = getTruckFrontTexture();
  truckFrontTexture.center = new THREE.Vector2(0.5, 0.5);
  truckFrontTexture.rotation = Math.PI / 2;

  const truckLeftTexture = getTruckSideTexture();
  truckLeftTexture.flipY = false;

  const truckRightTexture = getTruckSideTexture();

  const cabin = new THREE.Mesh(new THREE.BoxBufferGeometry(25, 30, 30), [
    new THREE.MeshLambertMaterial({ color, map: truckFrontTexture }),
    new THREE.MeshLambertMaterial({ color }), // back
    new THREE.MeshLambertMaterial({ color, map: truckLeftTexture }),
    new THREE.MeshLambertMaterial({ color, map: truckRightTexture }),
    new THREE.MeshLambertMaterial({ color }), // top
    new THREE.MeshLambertMaterial({ color }) // bottom
  ]);
  cabin.position.x = 40;
  cabin.position.z = 20;
  cabin.castShadow = true;
  cabin.receiveShadow = true;
  truck.add(cabin);

  const backWheel = Wheel();
  backWheel.position.x = -30;
  truck.add(backWheel);

  const middleWheel = Wheel();
  middleWheel.position.x = 10;
  truck.add(middleWheel);

  const frontWheel = Wheel();
  frontWheel.position.x = 38;
  truck.add(frontWheel);

  if (config.showHitZones) {
    truck.userData.hitZone1 = HitZone();
    truck.userData.hitZone2 = HitZone();
    truck.userData.hitZone3 = HitZone();
  }

  return truck;
}

function HitZone() {
  const hitZone = new THREE.Mesh(
    new THREE.CylinderGeometry(20, 20, 60, 30),
    new THREE.MeshLambertMaterial({ color: 0xff0000 })
  );
  hitZone.position.z = 25;
  hitZone.rotation.x = Math.PI / 2;

  scene.add(hitZone);
  return hitZone;
}

function Wheel() {
  const wheel = new THREE.Mesh(wheelGeometry, wheelMaterial);
  wheel.position.z = 6;
  wheel.castShadow = false;
  wheel.receiveShadow = false;
  return wheel;
}

function Tree() {
  const tree = new THREE.Group();

  const trunk = new THREE.Mesh(treeTrunkGeometry, treeTrunkMaterial);
  trunk.position.z = 10;
  trunk.castShadow = true;
  trunk.receiveShadow = true;
  trunk.matrixAutoUpdate = false;
  tree.add(trunk);

  const treeHeights = [45, 60, 75];
  const height = pickRandom(treeHeights);

  const crown = new THREE.Mesh(
    new THREE.SphereGeometry(height / 2, 30, 30),
    treeCrownMaterial
  );
  crown.position.z = height / 2 + 30;
  crown.castShadow = true;
  crown.receiveShadow = false;
  tree.add(crown);

  return tree;
}

accelerateButton.addEventListener("mousedown", function () {
  startGame();
  accelerate = true;
});
decelerateButton.addEventListener("mousedown", function () {
  startGame();
  decelerate = true;
});
accelerateButton.addEventListener("mouseup", function () {
  accelerate = false;
});
decelerateButton.addEventListener("mouseup", function () {
  decelerate = false;
});
window.addEventListener("keydown", function (event) {
  if (event.key == "ArrowUp") {
    startGame();
    accelerate = true;
    return;
  }
  if (event.key == "ArrowDown") {
    decelerate = true;
    return;
  }
  if (event.key == "R" || event.key == "r") {
    reset();
    return;
  }
});
window.addEventListener("keyup", function (event) {
  if (event.key == "ArrowUp") {
    accelerate = false;
    return;
  }
  if (event.key == "ArrowDown") {
    decelerate = false;
    return;
  }
});

function animation(timestamp) {
  if (!lastTimestamp) {
    lastTimestamp = timestamp;
    return;
  }

  const timeDelta = timestamp - lastTimestamp;

  movePlayerCar(timeDelta);

  const laps = Math.floor(Math.abs(playerAngleMoved) / (Math.PI * 2));

  // Update score if it changed
  if (laps != score) {
    score = laps;
    scoreElement.innerText = score;
  }

  // Add a new vehicle at the beginning and with every 5th lap
  if (otherVehicles.length < (laps + 1) / 5) addVehicle();

  moveOtherVehicles(timeDelta);

  hitDetection();

  renderer.render(scene, camera);
  lastTimestamp = timestamp;
}

function movePlayerCar(timeDelta) {
  const playerSpeed = getPlayerSpeed();
  playerAngleMoved -= playerSpeed * timeDelta;

  const totalPlayerAngle = playerAngleInitial + playerAngleMoved;

  const playerX = Math.cos(totalPlayerAngle) * trackRadius - arcCenterX;
  const playerY = Math.sin(totalPlayerAngle) * trackRadius;

  playerCar.position.x = playerX;
  playerCar.position.y = playerY;

  playerCar.rotation.z = totalPlayerAngle - Math.PI / 2;
}

function moveOtherVehicles(timeDelta) {
  otherVehicles.forEach((vehicle) => {
    if (vehicle.clockwise) {
      vehicle.angle -= speed * timeDelta * vehicle.speed;
    } else {
      vehicle.angle += speed * timeDelta * vehicle.speed;
    }

    const vehicleX = Math.cos(vehicle.angle) * trackRadius + arcCenterX;
    const vehicleY = Math.sin(vehicle.angle) * trackRadius;
    const rotation =
      vehicle.angle + (vehicle.clockwise ? -Math.PI / 2 : Math.PI / 2);
    vehicle.mesh.position.x = vehicleX;
    vehicle.mesh.position.y = vehicleY;
    vehicle.mesh.rotation.z = rotation;
  });
}

function getPlayerSpeed() {
  if (accelerate) return speed * 2;
  if (decelerate) return speed * 0.5;
  return speed;
}

function addVehicle() {
  const vehicleTypes = ["car", "truck"];

  const type = pickRandom(vehicleTypes);
  const speed = getVehicleSpeed(type);
  const clockwise = Math.random() >= 0.5;

  const angle = clockwise ? Math.PI / 2 : -Math.PI / 2;

  const mesh = type == "car" ? Car() : Truck();
  scene.add(mesh);

  otherVehicles.push({ mesh, type, speed, clockwise, angle });
}

function getVehicleSpeed(type) {
  if (type == "car") {
    const minimumSpeed = 1;
    const maximumSpeed = 2;
    return minimumSpeed + Math.random() * (maximumSpeed - minimumSpeed);
  }
  if (type == "truck") {
    const minimumSpeed = 0.6;
    const maximumSpeed = 1.5;
    return minimumSpeed + Math.random() * (maximumSpeed - minimumSpeed);
  }
}

function getHitZonePosition(center, angle, clockwise, distance) {
  const directionAngle = angle + clockwise ? -Math.PI / 2 : +Math.PI / 2;
  return {
    x: center.x + Math.cos(directionAngle) * distance,
    y: center.y + Math.sin(directionAngle) * distance
  };
}

function hitDetection() {
  const playerHitZone1 = getHitZonePosition(
    playerCar.position,
    playerAngleInitial + playerAngleMoved,
    true,
    15
  );

  const playerHitZone2 = getHitZonePosition(
    playerCar.position,
    playerAngleInitial + playerAngleMoved,
    true,
    -15
  );

  if (config.showHitZones) {
    playerCar.userData.hitZone1.position.x = playerHitZone1.x;
    playerCar.userData.hitZone1.position.y = playerHitZone1.y;

    playerCar.userData.hitZone2.position.x = playerHitZone2.x;
    playerCar.userData.hitZone2.position.y = playerHitZone2.y;
  }

  const hit = otherVehicles.some((vehicle) => {
    if (vehicle.type == "car") {
      const vehicleHitZone1 = getHitZonePosition(
        vehicle.mesh.position,
        vehicle.angle,
        vehicle.clockwise,
        15
      );

      const vehicleHitZone2 = getHitZonePosition(
        vehicle.mesh.position,
        vehicle.angle,
        vehicle.clockwise,
        -15
      );

      if (config.showHitZones) {
        vehicle.mesh.userData.hitZone1.position.x = vehicleHitZone1.x;
        vehicle.mesh.userData.hitZone1.position.y = vehicleHitZone1.y;

        vehicle.mesh.userData.hitZone2.position.x = vehicleHitZone2.x;
        vehicle.mesh.userData.hitZone2.position.y = vehicleHitZone2.y;
      }

      // The player hits another vehicle
      if (getDistance(playerHitZone1, vehicleHitZone1) < 40) return true;
      if (getDistance(playerHitZone1, vehicleHitZone2) < 40) return true;

      // Another vehicle hits the player
      if (getDistance(playerHitZone2, vehicleHitZone1) < 40) return true;
    }

    if (vehicle.type == "truck") {
      const vehicleHitZone1 = getHitZonePosition(
        vehicle.mesh.position,
        vehicle.angle,
        vehicle.clockwise,
        35
      );

      const vehicleHitZone2 = getHitZonePosition(
        vehicle.mesh.position,
        vehicle.angle,
        vehicle.clockwise,
        0
      );

      const vehicleHitZone3 = getHitZonePosition(
        vehicle.mesh.position,
        vehicle.angle,
        vehicle.clockwise,
        -35
      );

      if (config.showHitZones) {
        vehicle.mesh.userData.hitZone1.position.x = vehicleHitZone1.x;
        vehicle.mesh.userData.hitZone1.position.y = vehicleHitZone1.y;

        vehicle.mesh.userData.hitZone2.position.x = vehicleHitZone2.x;
        vehicle.mesh.userData.hitZone2.position.y = vehicleHitZone2.y;

        vehicle.mesh.userData.hitZone3.position.x = vehicleHitZone3.x;
        vehicle.mesh.userData.hitZone3.position.y = vehicleHitZone3.y;
      }

      // The player hits another vehicle
      if (getDistance(playerHitZone1, vehicleHitZone1) < 40) return true;
      if (getDistance(playerHitZone1, vehicleHitZone2) < 40) return true;
      if (getDistance(playerHitZone1, vehicleHitZone3) < 40) return true;

      // Another vehicle hits the player
      if (getDistance(playerHitZone2, vehicleHitZone1) < 40) return true;
    }
  });

  if (hit) {
    if (resultsElement) resultsElement.style.display = "flex";
    renderer.setAnimationLoop(null); // Stop animation loop
  }
}

window.addEventListener("resize", () => {
  console.log("resize", window.innerWidth, window.innerHeight);

  // Adjust camera
  const newAspectRatio = window.innerWidth / window.innerHeight;
  const adjustedCameraHeight = cameraWidth / newAspectRatio;

  camera.top = adjustedCameraHeight / 2;
  camera.bottom = adjustedCameraHeight / -2;
  camera.updateProjectionMatrix(); // Must be called after change

  positionScoreElement();

  // Reset renderer
  renderer.setSize(window.innerWidth, window.innerHeight);
  renderer.render(scene, camera);
});

scripts

<script src="https://cdnjs.cloudflare.com/ajax/libs/three.js/r126/three.min.js"></script>

style.css

@import url("https://fonts.googleapis.com/css?family=Press+Start+2P");

body {
  margin: 0;
  color: white;
  font-family: "Segoe UI", Tahoma, Geneva, Verdana, sans-serif;
}

button {
  outline: none;
  cursor: pointer;
  border: none;
  box-shadow: 3px 5px 0px 0px rgba(0, 0, 0, 0.75);
}

a,
a:visited {
  color: inherit;
}

#score {
  position: absolute;
  font-family: "Press Start 2P", cursive;
  font-size: 0.9em;
  color: white;
  transform: translate(-50%, -50%);
  opacity: 0.9;
  max-width: 100px;
  text-align: center;
  line-height: 1.6em;
}

#controls {
  position: absolute;
  bottom: 50px;
  left: 50px;
  display: none;
}

#controls #buttons {
  width: 80px;
  opacity: 0;
  transition: opacity 2s;
}

#controls #instructions {
  margin-left: 20px;
  max-width: 300px;
  background-color: rgba(0, 0, 0, 0.2);
  padding: 20px;
  opacity: 0;
  transition: opacity 2s;
}

#controls button {
  width: 100%;
  height: 40px;
  background-color: white;
  border: 1px solid black;
  margin-bottom: 10px;
}

#results {
  position: absolute;
  align-items: center;
  justify-content: center;
  height: 100%;
  width: 100%;
  background-color: rgba(20, 20, 20, 0.75);
  display: none;
  z-index: 51;
}

#results .content {
  max-width: 350px;
  padding: 50px;
  border-radius: 20px;
}

#result-youtube {
  display: flex;
  background-color: white;
  padding: 20px;
  color: black;
  text-decoration: none;
  cursor: pointer;
}

#result-youtube span {
  margin-top: 5px;
  margin-left: 20px;
}

.youtube,
#youtube-card {
  display: none;
  color: black;
}

#youtube-main {
  opacity: 0;
  transition: opacity 2s;
}

@media (min-height: 425px) {
  #score {
    font-size: 1.5em;
    max-width: 150px;
  }

  #controls {
    display: flex;
  }

  /** Youtube logo by https://codepen.io/alvaromontoro */
  .youtube {
    z-index: 50;
    width: 100px;
    min-width: 100px;
    height: 70px;
    position: fixed;
    bottom: 50px;
    right: 50px;
    transform: scale(0.8);
    transition: transform 0.5s;
    display: block;
    background: red;
    border-radius: 50% / 11%;
  }

  #results .youtube {
    position: relative;
    right: 0;
    bottom: 0;
  }

  .youtube:hover,
  .youtube:focus {
    transform: scale(0.9);
    color: black;
  }

  .youtube::before {
    content: "";
    display: block;
    position: absolute;
    top: 7.5%;
    left: -6%;
    width: 112%;
    height: 85%;
    background: red;
    border-radius: 9% / 50%;
  }

  .youtube::after {
    content: "";
    display: block;
    position: absolute;
    top: 20px;
    left: 40px;
    width: 45px;
    height: 30px;
    border: 15px solid transparent;
    box-sizing: border-box;
    border-left: 30px solid white;
  }

  .youtube span {
    font-size: 0;
    position: absolute;
    width: 0;
    height: 0;
    overflow: hidden;
  }

  .youtube:hover + #youtube-card {
    z-index: 49;
    display: block;
    position: fixed;
    bottom: 42px;
    width: 300px;
    background-color: white;
    right: 40px;
    padding: 25px 130px 25px 25px;
  }
}

traffic-run-game-with-three-js.markdown

Traffic Run Game with Three.js

Three.js video tutorial explaining the source code

Youtube: https://youtu.be/JhgBwJn1bQw

In the tutorial, we go through the source code of this game. We cover, how to set up a Three.js scene with box objects, how to add lights, how to set up the camera, how to add animation and event handlers. We also add textures with HTML Canvas and learn how to draw 2D shapes in Three.js then how to turn them into extruded geometries.

Check out my YouTube channel for other game tutorials: https://www.youtube.com/channel/UCxhgW0Q5XLvIoXHAfQXg9oQ

The game in the video is heavily inspired by the mobile game Loop Driver: https://apps.apple.com/us/app/loop-drive-crash-race/id992442150

A Pen by HARUN PEHLİVAN on CodePen.

License.