Skip to main content

AreaMeasurement

Source

Copying and pasting? We've got you covered! You can find the full source code of this tutorial here.

📐 Measuring areas​

Space control is one of the most important elements of BIM applications. In this tutorial, you'll learn how to expose an area measurement tool to your end users. We will import:

  • three to create some 3D items.
  • @thatopen/components to set up the barebone of our app.
  • @thatopen/components-front to use some frontend-oriented components.
  • Stats.js (optional) to measure the performance of our app.
import Stats from "stats.js";
import * as OBC from "@thatopen/components";
import * as THREE from "three";
import * as OBCF from "@thatopen/components-front";

🌎 Setting up a simple scene​

We will start by creating a simple scene with a camera and a renderer. If you don't know how to set up a scene, you can check the Worlds tutorial.

const container = document.getElementById("container")!;

const components = new OBC.Components();

const worlds = components.get(OBC.Worlds);

const world = worlds.create<
  OBC.SimpleScene,
  OBC.SimpleCamera,
  OBCF.PostproductionRenderer
>();

world.scene = new OBC.SimpleScene(components);
world.renderer = new OBCF.PostproductionRenderer(components, container);
world.camera = new OBC.SimpleCamera(components);

components.init();
world.camera.controls.setLookAt(5, 5, 5, 0, 0, 0);
world.scene.setup();

const grids = components.get(OBC.Grids);
grids.create(world);

We'll make the background of the scene transparent so that it looks good in our docs page, but you don't have to do that in your app!

world.scene.three.background = null;

🎲 Creating a Cube Mesh​

For this tutorial we will use a Cube, you can add any geometry as per your preference. We will create a Cube with 3x3x3 dimensions and use red color for the material.

const cubeGeometry = new THREE.BoxGeometry(3, 3, 3);
const cubeMaterial = new THREE.MeshStandardMaterial({ color: "#6528D7" });
const cube = new THREE.Mesh(cubeGeometry, cubeMaterial);
cube.position.set(0, 1.5, 0);
world.scene.three.add(cube);
world.meshes.add(cube);

🛠️ Getting the area measurements​

First, let's get an instance of the area measurement component and initialize it:

const areaDims = components.get(OBCF.AreaMeasurement);
areaDims.world = world;
areaDims.enabled = true;

🖱️ Setting up mouse events​

Now, we'll define how to create the area dimensions. In this case, we'll keep it simple and use the double click event of the container HTML element. We'll also use the right mouse button to end the creation of the area.

container.ondblclick = () => areaDims.create();
container.oncontextmenu = () => areaDims.endCreation();

🧹 Deleting the Dimensions​

Now that we know how to make multiple dimensions, we'll learn how to delete them when necessary. Dimensions can be removed using the deleteAll() method, which deletes all the created dimensions. Again, we'll keep it simple and bind this event to the keydown event. Specifically, it will fire when the user presses the Delete or Backspace key.

window.onkeydown = (event) => {
  if (event.code === "Delete" || event.code === "Backspace") {
    areaDims.deleteAll();
  }
};

⏱️ Measuring the performance (optional)​

We'll use the Stats.js to measure the performance of our app. We will add it to the top left corner of the viewport. This way, we'll make sure that the memory consumption and the FPS of our app are under control.

const stats = new Stats();
stats.showPanel(2);
document.body.append(stats.dom);
stats.dom.style.left = "0px";
stats.dom.style.zIndex = "unset";
world.renderer.onBeforeUpdate.add(() => stats.begin());
world.renderer.onAfterUpdate.add(() => stats.end());

🎉 Wrap up​

That's it! You have created an app that can create and delete area dimensions on any 3D object. Congratulations!