BufferGeometry

Object3D

Object3D.add Object3D.applyMatrix4 Object3D.applyQuaternion Object3D.attach Object3D.clone Object3D.copy Object3D.getObjectById Object3D.getObjectByName Object3D.getObjectByProperty Object3D.getObjectsByProperty Object3D.getWorldPosition Object3D.getWorldQuaternion Object3D.getWorldScale Object3D.getWorldDirection Object3D.localToWorld Object3D.lookAt Object3D.raycast Object3D.remove Object3D.removeFromParent Object3D.clear Object3D.rotateOnAxis Object3D.rotateOnWorldAxis Object3D.rotateX Object3D.rotateY Object3D.rotateZ Object3D.setRotationFromAxisAngle Object3D.setRotationFromEuler Object3D.setRotationFromMatrix Object3D.setRotationFromQuaternion Object3D.toJSON Object3D.translateOnAxis Object3D.translateX Object3D.translateY Object3D.translateZ Object3D.traverse Object3D.traverseVisible Object3D.traverseAncestors Object3D.updateMatrix Object3D.updateMatrixWorld Object3D.updateWorldMatrix Object3D.worldToLocal

Raycaster

Raycaster.set Raycaster.setFromCamera Raycaster.intersectObject Raycaster.intersectObjects

Camera

Camera.clone Camera.copy Camera.getWorldDirection

CubeCamera

CubeCamera.update

PerspectiveCamera

PerspectiveCamera.clearViewOffset PerspectiveCamera.getEffectiveFOV PerspectiveCamera.getFilmHeight PerspectiveCamera.getFilmWidth PerspectiveCamera.getFocalLength PerspectiveCamera.setFocalLength PerspectiveCamera.setViewOffset PerspectiveCamera.updateProjectionMatrix PerspectiveCamera.toJSON

OrthographicCamera

OrthographicCamera.setViewOffset OrthographicCamera.clearViewOffset OrthographicCamera.updateProjectionMatrix OrthographicCamera.toJSON

StereoCamera

StereoCamera.update

Clock

Clock.start Clock.stop Clock.getElapsedTime Clock.getDelta

Curve

Curve.getPoint Curve.getPointAt Curve.getPoints Curve.getSpacedPoints Curve.getLengths Curve.updateArcLengths Curve.getUtoTmapping Curve.getTangent Curve.getTangentAt Curve.computeFrenetFrames Curve.clone Curve.copy Curve.toJSON Curve.fromJSON

CurvePath

CurvePath.add CurvePath.closePath CurvePath.getCurveLengths CurvePath.getPoints CurvePath.getSpacedPoints

Path

Path.absarc Path.absellipse Path.arc Path.bezierCurveTo Path.ellipse Path.lineTo Path.moveTo Path.quadraticCurveTo Path.setFromPoints Path.splineThru

Shape

Shape.extractPoints Shape.getPointsHoles

ShapePath

ShapePath.moveTo ShapePath.lineTo ShapePath.quadraticCurveTo ShapePath.bezierCurveTo ShapePath.splineThru ShapePath.toShapes

ArrowHelper

ArrowHelper.setColor ArrowHelper.setLength ArrowHelper.setDirection ArrowHelper.dispose

AxesHelper

AxesHelper.setColors AxesHelper.dispose

BoxHelper

BoxHelper.update BoxHelper.setFromObject BoxHelper.dispose

Box3Helper

Box3Helper.updateMatrixWorld Box3Helper.dispose

CameraHelper

CameraHelper.dispose CameraHelper.setColors CameraHelper.update

DirectionalLightHelper

DirectionalLightHelper.dispose DirectionalLightHelper.update

GridHelper

GridHelper.dispose

PolarGridHelper

PolarGridHelper.dispose

HemisphereLightHelper

HemisphereLightHelper.update HemisphereLightHelper.dispose

PlaneHelper

PlaneHelper.updateMatrixWorld PlaneHelper.dispose

PointLightHelper

PointLightHelper.dispose PointLightHelper.update

SkeletonHelper

SkeletonHelper.dispose

SpotLightHelper

SpotLightHelper.dispose SpotLightHelper.update

Light

Light.dispose Light.copy Light.toJSON

PointLight

PointLight.dispose PointLight.copy

RectAreaLight

RectAreaLight.copy

SpotLight

SpotLight.dispose SpotLight.copy

DirectionalLight

DirectionalLight.dispose DirectionalLight.copy

HemisphereLight

HemisphereLight.copy

LightShadow

LightShadow.getFrameExtents LightShadow.updateMatrices LightShadow.getFrustum LightShadow.getViewportCount LightShadow.dispose LightShadow.copy LightShadow.clone LightShadow.toJSON

PointLightShadow

PointLightShadow.updateMatrices

AnimationLoader

AnimationLoader.load AnimationLoader.parse

AudioLoader

AudioLoader.load

BufferGeometryLoader

BufferGeometryLoader.load BufferGeometryLoader.parse

CompressedTextureLoader

CompressedTextureLoader.load

CubeTextureLoader

CubeTextureLoader.load

DataTextureLoader

DataTextureLoader.load

FileLoader

FileLoader.load FileLoader.setMimeType FileLoader.setResponseType

ImageBitmapLoader

ImageBitmapLoader.load ImageBitmapLoader.setOptions

ImageLoader

ImageLoader.load

Loader

Loader.load Loader.loadAsync Loader.parse Loader.setCrossOrigin Loader.setWithCredentials Loader.setPath Loader.setResourcePath Loader.setRequestHeader

LoaderUtils

LoaderUtils.decodeText LoaderUtils.extractUrlBase LoaderUtils.resolveURL

MaterialLoader

MaterialLoader.load MaterialLoader.parse MaterialLoader.setTextures

ObjectLoader

ObjectLoader.load ObjectLoader.parse ObjectLoader.parseGeometries ObjectLoader.parseMaterials ObjectLoader.parseImages ObjectLoader.parseTextures ObjectLoader.parseObject

TextureLoader

TextureLoader.load

LoadingManager

LoadingManager.addHandler LoadingManager.getHandler LoadingManager.removeHandler LoadingManager.resolveURL LoadingManager.setURLModifier LoadingManager.itemStart LoadingManager.itemEnd LoadingManager.itemError

Material

Material.clone Material.copy Material.dispose Material.onBeforeCompile Material.customProgramCacheKey Material.setValues Material.toJSON

Box2

Box3

Color

Cylindrical

Cylindrical.clone Cylindrical.copy Cylindrical.set Cylindrical.setFromVector3 Cylindrical.setFromCartesianCoords

Euler

Euler.copy Euler.clone Euler.equals Euler.fromArray Euler.reorder Euler.set Euler.setFromRotationMatrix Euler.setFromQuaternion Euler.setFromVector3 Euler.toArray

Frustum

Frustum.clone Frustum.containsPoint Frustum.copy Frustum.intersectsBox Frustum.intersectsObject Frustum.intersectsSphere Frustum.intersectsSprite Frustum.set Frustum.setFromProjectionMatrix

Interpolant

Interpolant.evaluate

Line3

Line3.applyMatrix4 Line3.at Line3.clone Line3.closestPointToPoint Line3.closestPointToPointParameter Line3.copy Line3.delta Line3.distance Line3.distanceSq Line3.equals Line3.getCenter Line3.set

MathUtils

Matrix3

Matrix4

Plane

Plane.applyMatrix4 Plane.clone Plane.coplanarPoint Plane.copy Plane.distanceToPoint Plane.distanceToSphere Plane.equals Plane.intersectLine Plane.intersectsBox Plane.intersectsLine Plane.intersectsSphere Plane.negate Plane.normalize Plane.projectPoint Plane.set Plane.setComponents Plane.setFromCoplanarPoints Plane.setFromNormalAndCoplanarPoint Plane.translate

Quaternion

AnimationAction

AnimationClip

AnimationClip.clone AnimationClip.optimize AnimationClip.resetDuration AnimationClip.toJSON AnimationClip.trim AnimationClip.validate AnimationClip.CreateClipsFromMorphTargetSequences AnimationClip.CreateFromMorphTargetSequence AnimationClip.findByName AnimationClip.parse AnimationClip.parseAnimation AnimationClip.toJSON

AnimationMixer

AnimationMixer.clipAction AnimationMixer.existingAction AnimationMixer.getRoot AnimationMixer.stopAllAction AnimationMixer.update AnimationMixer.setTime AnimationMixer.uncacheClip AnimationMixer.uncacheRoot AnimationMixer.uncacheAction

AnimationObjectGroup

AnimationObjectGroup.add AnimationObjectGroup.remove AnimationObjectGroup.uncache

AnimationUtils

AnimationUtils.arraySlice AnimationUtils.convertArray AnimationUtils.flattenJSON AnimationUtils.getKeyframeOrder AnimationUtils.isTypedArray AnimationUtils.makeClipAdditive AnimationUtils.sortedArray AnimationUtils.subclip

keyframeTrack

keyframeTrack.clone keyframeTrack.createInterpolant keyframeTrack.getInterpolation keyframeTrack.getValueSize keyframeTrack.interpolantFactoryMethodDiscrete keyframeTrack.InterpolantFactoryMethodLinear keyframeTrack.InterpolantFactoryMethodLinear keyframeTrack.InterpolantFactoryMethodSmooth keyframeTrack.optimize keyframeTrack.scale keyframeTrack.setInterpolation keyframeTrack.shift keyframeTrack.trim keyframeTrack.validate keyframeTrack.toJSON

PropertyBinding

PropertyBinding.getValue PropertyBinding.setValue PropertyBinding.bind PropertyBinding.unbind PropertyBinding.Composite PropertyBinding.create PropertyBinding.parseTrackName PropertyBinding.findNode

PropertyMixer

PropertyMixer.accumulate PropertyMixer.accumulateAdditive PropertyMixer.apply PropertyMixer.saveOriginalState PropertyMixer.restoreOriginalState PropertyMixer.resetOriginalState

BooleanKeyframeTrack

BooleanKeyframeTrack.InterpolantFactoryMethodLinear BooleanKeyframeTrack.InterpolantFactoryMethodSmooth

QuaternionKeyframeTrack

QuaternionKeyframeTrack.InterpolantFactoryMethodLinear

StringKeyframeTrack

StringKeyframeTrack.InterpolantFactoryMethodLinear StringKeyframeTrack.InterpolantFactoryMethodSmooth

Audio

AudioAnalyser

AudioAnalyser.getFrequencyData AudioAnalyser.getAverageFrequency

AudioContext

AudioContext.getContext AudioContext.setContext

AudioListener

AudioListener.getInput AudioListener.removeFilter AudioListener.getFilter AudioListener.setFilter AudioListener.getMasterVolume AudioListener.setMasterVolume

PositionalAudio

PositionalAudio.getOutput PositionalAudio.getRefDistance PositionalAudio.setRefDistance PositionalAudio.getRolloffFactor PositionalAudio.setRolloffFactor PositionalAudio.getDistanceModel PositionalAudio.setDistanceModel PositionalAudio.getMaxDistance PositionalAudio.setMaxDistance PositionalAudio.setDirectionalCone

PerspectiveCamera.getFocalLength()

PerspectiveCamera.getFocalLength() 方法用于获取透视相机的焦距（单位：像素）。

语法

PerspectiveCamera.getFocalLength()

返回值

返回值类型：number
返回值：透视相机的焦距，单位为像素。

描述

透视相机是使用有限的视野来模拟人眼的视角，具有近大远小的特点。焦距是透视相机控制近小远大的一个参数，它代表了相机到物体的距离。通过调整焦距，可以控制视野的大小，进而达到所需的效果。

PerspectiveCamera.getFocalLength() 方法通过内部计算得出透视相机的焦距。可以用来获取当前焦距的值。

示例

以下示例演示了如何使用 PerspectiveCamera.getFocalLength() 方法获取透视相机的焦距：

const camera = new THREE.PerspectiveCamera(75, window.innerWidth / window.innerHeight, 0.1, 1000);

const focalLength = camera.getFocalLength();
console.log(focalLength);

输出结果为透视相机的焦距值。

参考