javascript
/
three.js
mirror of https://github.com/tazdij/three.js.git


			
							123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200
							<!DOCTYPE html>
<html lang="en">
	<head>
		<meta charset="utf-8" />
		<base href="../../../" />
		<script src="page.js"></script>
		<link type="text/css" rel="stylesheet" href="page.css" />
	</head>
	<body>
		[page:Object3D] &rarr; [page:Light] &rarr;

		<h1>[name]</h1>

		<p class="desc">
			This light gets emitted from a single point in one direction, along a cone that increases in size
			the further from the light it gets. <br /><br />

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

		<h2>Code Example</h2>
		<code>
		// white spotlight shining from the side, modulated by a texture, casting a shadow

		const spotLight = new THREE.SpotLight( 0xffffff );
		spotLight.position.set( 100, 1000, 100 );
		spotLight.map = new THREE.TextureLoader().load( url );

		spotLight.castShadow = true;

		spotLight.shadow.mapSize.width = 1024;
		spotLight.shadow.mapSize.height = 1024;

		spotLight.shadow.camera.near = 500;
		spotLight.shadow.camera.far = 4000;
		spotLight.shadow.camera.fov = 30;

		scene.add( spotLight );
		</code>

		<h2>Examples</h2>

		<p>
			[example:webgl_lights_spotlight lights / spotlight ]<br />
			[example:webgl_lights_spotlights lights / spotlights ]
		</p>

		<h2>Constructor</h2>


		<h3>[name]( [param:Integer color], [param:Float intensity], [param:Float distance], [param:Radians angle], [param:Float penumbra], [param:Float decay] )</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 />
			[page:Float distance] - Maximum range of the light. Default is 0 (no limit).<br />
			[page:Radians angle] - Maximum angle of light dispersion from its direction whose upper
			bound is Math.PI/2.<br />
			[page:Float penumbra] - Percent of the spotlight cone that is attenuated due to penumbra.
			Takes values between zero and 1. Default is zero.<br />
			[page:Float decay] - The amount the light dims along the distance of the light.<br /><br />

			Creates a new [name].
		</p>

		<h2>Properties</h2>

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

		<h3>[property:Float angle]</h3>
		<p>
			Maximum extent of the spotlight, in radians, from its direction. Should be no more than
			`Math.PI/2`. The default is `Math.PI/3`.
		</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:SpotLightShadow] for details.
			The default is `false`.
		</p>

		<h3>[property:Float decay]</h3>
		<p>
			The amount the light dims along the distance of the light. Default is `2`.<br />
			In context of physically-correct rendering the default value should not be changed.
		</p>

		<h3>[property:Float distance]</h3>
		<p>
			`Default mode` — When distance is zero, light does not attenuate. When distance is
			non-zero, light will attenuate linearly from maximum intensity at the light's position down to
			zero at this distance from the light.
		</p>
		<p>
			`[page:WebGLRenderer.physicallyCorrectLights Physically correct] mode` — When distance
			is zero, light will attenuate according to inverse-square law to infinite distance. When
			distance is non-zero, light will attenuate according to inverse-square law until near the
			distance cutoff, where it will then attenuate quickly and smoothly to `0`. Inherently, cutoffs
			are not physically correct.
		</p>
		<p>
			Default is `0.0`.
		</p>

		<h3>[property:Float intensity]</h3>
		<p>
			The light's intensity. Default is `1`.<br />
			In [page:WebGLRenderer.physicallyCorrectLights physically correct] mode, intensity is the luminous
			intensity of the light measured in candela (cd).<br /><br />

			Changing the intensity will also change the light's power.

		</p>

		<h3>[property:Boolean isSpotLight]</h3>
		<p>
			Read-only flag to check if a given object is of type [name].
		</p>

		<h3>[property:Float penumbra]</h3>
		<p>
			Percent of the spotlight cone that is attenuated due to penumbra. Takes values between
			zero and 1. The default is `0.0`.
		</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:Float power]</h3>
		<p>
			The light's power.<br />
			In [page:WebGLRenderer.physicallyCorrectLights physically correct] mode, power is the luminous
			power of the light measured in lumens (lm). <br /><br />

			Changing the power will also change the light's intensity.
		</p>


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


		<h3>[property:Object3D target]</h3>
		<p>
			The Spotlight 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
			<code>
				scene.add( light.target );
			</code>

			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:
			<code>
const targetObject = new THREE.Object3D();
scene.add(targetObject);

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

		<h3>[property:Texture map]</h3>
		<p>
			A [page:Texture] used to modulate the color of the light. The spot light color is mixed
			with the RGB value of this texture, with a ratio corresponding to its
			alpha value. The cookie-like masking effect is reproduced using pixel values (0, 0, 0, 1-cookie_value).
			*Warning*: [param:SpotLight map] is disabled if [param:SpotLight castShadow] is *false*. 
		</p>

		<h2>Methods</h2>

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

		<h3>[method:undefined dispose]()</h3>
		<p>
			Frees the GPU-related resources allocated by this instance. Call this method whenever this instance is no longer used in your app.
		</p>

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

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