samien
/
three.js
oglindă de https://github.com/mrdoob/three.js.git


			
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    <title>Drawing Lines</title>
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        <h1>Drawing Lines</h1>
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          <p>
            Let's say you want to draw a line or a circle, not a wireframe `Mesh`.
            First we need to set up the renderer, scene and camera (see the Creating a scene page).
          </p>
    
          <p>Here is the code that we will use:</p>
<pre class="prettyprint notranslate lang-js" translate="no">
const renderer = new THREE.WebGLRenderer();
renderer.setSize( window.innerWidth, window.innerHeight );
document.body.appendChild( renderer.domElement );

const camera = new THREE.PerspectiveCamera( 45, window.innerWidth / window.innerHeight, 1, 500 );
camera.position.set( 0, 0, 100 );
camera.lookAt( 0, 0, 0 );

const scene = new THREE.Scene();
</pre>
          <p>Next thing we will do is define a material. For lines we have to use `LineBasicMaterial` or `LineDashedMaterial`.</p>
<pre class="prettyprint notranslate lang-js" translate="no">
//create a blue LineBasicMaterial
const material = new THREE.LineBasicMaterial( { color: 0x0000ff } );
</pre>
    
          <p>
            After material we will need a geometry with some vertices:
          </p>
    
<pre class="prettyprint notranslate lang-js" translate="no">
const points = [];
points.push( new THREE.Vector3( - 10, 0, 0 ) );
points.push( new THREE.Vector3( 0, 10, 0 ) );
points.push( new THREE.Vector3( 10, 0, 0 ) );

const geometry = new THREE.BufferGeometry().setFromPoints( points );
</pre>
    
          <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>
    
          <p>Now that we have points for two lines and a material, we can put them together to form a line.</p>
<pre class="prettyprint notranslate lang-js" translate="no">
const line = new THREE.Line( geometry, material );
</pre>
          <p>All that's left is to add it to the scene and call `renderer.render()`.</p>
    
<pre class="prettyprint notranslate lang-js" translate="no">
scene.add( line );
renderer.render( scene, camera );
</pre>
    
          <p>You should now be seeing an arrow pointing upwards, made from two blue lines.</p>

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