LengthMeasurement
Copying and pasting? We've got you covered! You can find the full source code of this tutorial here.
📐 Measuring lengths
Space control is one of the most important elements of BIM applications. In this tutorial, you'll learn how to expose a length measurement tool to your end users. We will import:
threeto create some 3D items.@thatopen/componentsto set up the barebone of our app.@thatopen/components-frontto use some frontend-oriented components.@thatopen/uito add some simple and cool UI menus.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 BUI from "@thatopen/ui";
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 length measurements
First, let's get an instance of the length measurement component and initialize it:
const dimensions = components.get(OBCF.LengthMeasurement);
dimensions.world = world;
dimensions.enabled = true;
dimensions.snapDistance = 1;
🖱️ Setting up mouse events
Now, we'll define how to create the length dimensions. In this case, we'll keep it simple and use the double click event of the container HTML element.
container.ondblclick = () => dimensions.create();
🧹 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. You can also use delete to just remove the dimension under the mouse cursor. 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") {
dimensions.delete();
}
};
⏱️ 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());
🧩 Adding some UI
We will use the @thatopen/ui library to add some simple and cool UI elements to our app. First, we need to call the init method of the BUI.Manager class to initialize the library:
BUI.Manager.init();
Now we will add some UI to have some control over the dimensions we create. For more information about the UI library, you can check the specific documentation for it!
const panel = BUI.Component.create<BUI.PanelSection>(() => {
return BUI.html`
<bim-panel active label="Length Measurement Tutorial" class="options-menu">
<bim-panel-section collapsed label="Controls">
<bim-label>Create dimension: Double click</bim-label>
<bim-label>Delete dimension: Delete</bim-label>
</bim-panel-section>
<bim-panel-section collapsed label="Others">
<bim-checkbox checked label="Dimensions enabled"
@change="${({ target }: { target: BUI.Checkbox }) => {
dimensions.enabled = target.value;
}}">
</bim-checkbox>
<bim-checkbox checked label="Dimensions visible"
@change="${({ target }: { target: BUI.Checkbox }) => {
dimensions.visible = target.value;
}}">
</bim-checkbox>
<bim-color-input
label="Dimensions Color" color="#202932"
@input="${({ target }: { target: BUI.ColorInput }) => {
dimensions.color.set(target.color);
}}">
</bim-color-input>
<bim-button label="Delete all"
@click="${() => {
dimensions.deleteAll();
}}">
</bim-button>
</bim-panel-section>
</bim-panel>
`;
});
document.body.append(panel);
And we will make some logic that adds a button to the screen when the user is visiting our app from their phone, allowing to show or hide the menu. Otherwise, the menu would make the app unusable.
const button = BUI.Component.create<BUI.PanelSection>(() => {
return BUI.html`
<bim-button class="phone-menu-toggler" icon="solar:settings-bold"
@click="${() => {
if (panel.classList.contains("options-menu-visible")) {
panel.classList.remove("options-menu-visible");
} else {
panel.classList.add("options-menu-visible");
}
}}">
</bim-button>
`;
});
document.body.append(button);
🎉 Wrap up
That's it! You have created an app that can create and delete length measurements on any 3D object. Congratulations!