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<!DOCTYPE html><html lang="en"><head>
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<meta charset="utf-8">
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<title>Drawing Lines</title>
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{
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"imports": {
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"three": "../../build/three.module.js"
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<body>
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<div class="container">
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<div class="lesson-title">
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<h1>Drawing Lines</h1>
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</div>
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<div class="lesson">
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<div class="lesson-main">
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<p>
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Let's say you want to draw a line or a circle, not a wireframe `Mesh`.
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First we need to set up the renderer, scene and camera (see the Creating a scene page).
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</p>
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<p>Here is the code that we will use:</p>
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<pre class="prettyprint notranslate lang-js" translate="no">
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const renderer = new THREE.WebGLRenderer();
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renderer.setSize( window.innerWidth, window.innerHeight );
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document.body.appendChild( renderer.domElement );
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const camera = new THREE.PerspectiveCamera( 45, window.innerWidth / window.innerHeight, 1, 500 );
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camera.position.set( 0, 0, 100 );
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camera.lookAt( 0, 0, 0 );
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const scene = new THREE.Scene();
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</pre>
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<p>Next thing we will do is define a material. For lines we have to use `LineBasicMaterial` or `LineDashedMaterial`.</p>
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<pre class="prettyprint notranslate lang-js" translate="no">
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//create a blue LineBasicMaterial
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const material = new THREE.LineBasicMaterial( { color: 0x0000ff } );
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</pre>
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<p>
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After material we will need a geometry with some vertices:
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</p>
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<pre class="prettyprint notranslate lang-js" translate="no">
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const points = [];
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points.push( new THREE.Vector3( - 10, 0, 0 ) );
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points.push( new THREE.Vector3( 0, 10, 0 ) );
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points.push( new THREE.Vector3( 10, 0, 0 ) );
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const geometry = new THREE.BufferGeometry().setFromPoints( points );
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</pre>
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<p>Note that lines are drawn between each consecutive pair of vertices, but not between the first and last (the line is not closed.)</p>
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<p>Now that we have points for two lines and a material, we can put them together to form a line.</p>
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<pre class="prettyprint notranslate lang-js" translate="no">
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const line = new THREE.Line( geometry, material );
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</pre>
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<p>All that's left is to add it to the scene and call `renderer.render()`.</p>
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<pre class="prettyprint notranslate lang-js" translate="no">
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scene.add( line );
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renderer.render( scene, camera );
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</pre>
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<p>You should now be seeing an arrow pointing upwards, made from two blue lines.</p>
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</div>
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</div>
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</div>
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<script src="../resources/prettify.js"></script>
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<script src="../resources/lesson.js"></script>
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</body></html>
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