javascript
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three.js
同期ミラー https://github.com/tazdij/three.js.git


			
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		[page:Object3D] &rarr; [page:Light] &rarr;

		<h1>[name]</h1>

		<p class="desc">
			A light that gets emitted in a specific direction. This light will behave as though it is
			infinitely far away and the rays produced from it are all parallel. The common use case
			for this is to simulate daylight; the sun is far enough away that its position can be
			considered to be infinite, and all light rays coming from it are parallel.<br /><br />

			This light can cast shadows - see the [page:DirectionalLightShadow] page for details.
		</p>

		<h2>A Note about Position, Target and rotation</h2>
		<p>
			A common point of confusion for directional lights is that setting the rotation has no effect.
			This is because three.js's DirectionalLight is the equivalent to what is often called a 'Target
			Direct Light' in other applications.<br /><br />

			This means that its direction is calculated as pointing
			from the light's [page:Object3D.position position] to	the [page:.target target]'s position
			(as opposed to a 'Free Direct Light' that just has a rotation component).<br /><br />

			The reason for this is to allow the light to cast shadows - the [page:.shadow shadow]
			camera needs a position to calculate shadows from.<br /><br />

			See the [page:.target target] property below for details on updating the target.
		</p>

		<h2>Code Example</h2>

		<code>
		// White directional light at half intensity shining from the top.
		const directionalLight = new THREE.DirectionalLight( 0xffffff, 0.5 );
		scene.add( directionalLight );
		</code>

		<h2>Examples</h2>
		<p>
			[example:misc_controls_fly controls / fly ]<br />
			[example:webgl_effects_parallaxbarrier effects / parallaxbarrier ]<br />
			[example:webgl_effects_stereo effects / stereo ]<br />
			[example:webgl_geometry_extrude_splines geometry / extrude / splines ]<br />
			[example:webgl_materials_bumpmap materials / bumpmap ]
		</p>

		<h2>Constructor</h2>

		<h3>[name]( [param:Integer color], [param:Float intensity] )</h3>
		<p>
			[page:Integer color] - (optional) hexadecimal color of the light. Default is 0xffffff (white).<br />
			[page:Float intensity] - (optional) numeric value of the light's strength/intensity. Default is 1.<br /><br />

			Creates a new [name].
		</p>

		<h2>Properties</h2>

		<p>See the base [page:Light Light] class for common properties.</p>

		<h3>[property:Boolean castShadow]</h3>
		<p>
			If set to *true* light will cast dynamic shadows. *Warning*: This is expensive and
			requires tweaking to get shadows looking right. See the [page:DirectionalLightShadow] for details.
			The default is *false*.
		</p>

		<h3>[property:Vector3 position]</h3>
		<p>
			This is set equal to [page:Object3D.DefaultUp] (0, 1, 0), so that the light shines from the top down.
		</p>

		<h3>[property:DirectionalLightShadow shadow]</h3>
		<p>
			A [page:DirectionalLightShadow] used to calculate shadows for this light.
		</p>

		<h3>[property:Object3D target]</h3>
		<p>
			The DirectionalLight points from its [page:.position position] to target.position. The default
			position of the target is *(0, 0, 0)*.<br />

			*Note*: For the target's position to be changed to anything other than the default,
			it must be added to the [page:Scene scene] using
		</p>
		<code>
		scene.add( light.target );
		</code>
		<p>
			This is so that the target's [page:Object3D.matrixWorld matrixWorld] gets automatically
			updated each frame.<br /><br />

			It is also possible to set the target to be another object in the scene (anything with a
			[page:Object3D.position position] property), like so:
		</p>
		<code>
		const targetObject = new THREE.Object3D();
		scene.add(targetObject);

		light.target = targetObject;
		</code>
		<p>
			The directionalLight will now track the target object.
		</p>


		<h2>Methods</h2>

		<p>See the base [page:Light Light] class for common methods.</p>

		<h3>[method:DirectionalLight dispose]()</h3>
		<p>
		Override of base class's [page:Light.dispose dispose].
		Disposes of this light's [page:DirectionalLightShadow shadow].
		</p>

		<h3>[method:DirectionalLight copy]( [param:DirectionalLight source] )</h3>
		<p>
		Copies value of all the properties from the [page:DirectionalLight source] to this
		DirectionalLight.
		</p>

		<h2>Source</h2>

		<p>
			[link:https://github.com/mrdoob/three.js/blob/master/src/[path].js src/[path].js]
		</p>
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