three
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JavaScript 3D library
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JavaScript
import { Camera } from './Camera.js';
import { RAD2DEG, DEG2RAD } from '../math/MathUtils.js';
import { Vector2 } from '../math/Vector2.js';
import { Vector3 } from '../math/Vector3.js';
const _v3 = /*@__PURE__*/ new Vector3();
const _minTarget = /*@__PURE__*/ new Vector2();
const _maxTarget = /*@__PURE__*/ new Vector2();
/**
* Camera that uses [perspective projection]{@link https://en.wikipedia.org/wiki/Perspective_(graphical)}.
*
* This projection mode is designed to mimic the way the human eye sees. It
* is the most common projection mode used for rendering a 3D scene.
*
* ```js
* const camera = new THREE.PerspectiveCamera( 45, width / height, 1, 1000 );
* scene.add( camera );
* ```
*
* @augments Camera
*/
class PerspectiveCamera extends Camera {
/**
* Constructs a new perspective camera.
*
* @param {number} [fov=50] - The vertical field of view.
* @param {number} [aspect=1] - The aspect ratio.
* @param {number} [near=0.1] - The camera's near plane.
* @param {number} [far=2000] - The camera's far plane.
*/
constructor( fov = 50, aspect = 1, near = 0.1, far = 2000 ) {
super();
/**
* This flag can be used for type testing.
*
* @type {boolean}
* @readonly
* @default true
*/
this.isPerspectiveCamera = true;
this.type = 'PerspectiveCamera';
/**
* The vertical field of view, from bottom to top of view,
* in degrees.
*
* @type {number}
* @default 50
*/
this.fov = fov;
/**
* The zoom factor of the camera.
*
* @type {number}
* @default 1
*/
this.zoom = 1;
/**
* The camera's near plane. The valid range is greater than `0`
* and less than the current value of {@link PerspectiveCamera#far}.
*
* Note that, unlike for the {@link OrthographicCamera}, `0` is <em>not</em> a
* valid value for a perspective camera's near plane.
*
* @type {number}
* @default 0.1
*/
this.near = near;
/**
* The camera's far plane. Must be greater than the
* current value of {@link PerspectiveCamera#near}.
*
* @type {number}
* @default 2000
*/
this.far = far;
/**
* Object distance used for stereoscopy and depth-of-field effects. This
* parameter does not influence the projection matrix unless a
* {@link StereoCamera} is being used.
*
* @type {number}
* @default 10
*/
this.focus = 10;
/**
* The aspect ratio, usually the canvas width / canvas height.
*
* @type {number}
* @default 1
*/
this.aspect = aspect;
/**
* Represents the frustum window specification. This property should not be edited
* directly but via {@link PerspectiveCamera#setViewOffset} and {@link PerspectiveCamera#clearViewOffset}.
*
* @type {?Object}
* @default null
*/
this.view = null;
/**
* Film size used for the larger axis. Default is `35` (millimeters). This
* parameter does not influence the projection matrix unless {@link PerspectiveCamera#filmOffset}
* is set to a nonzero value.
*
* @type {number}
* @default 35
*/
this.filmGauge = 35;
/**
* Horizontal off-center offset in the same unit as {@link PerspectiveCamera#filmGauge}.
*
* @type {number}
* @default 0
*/
this.filmOffset = 0;
this.updateProjectionMatrix();
}
copy( source, recursive ) {
super.copy( source, recursive );
this.fov = source.fov;
this.zoom = source.zoom;
this.near = source.near;
this.far = source.far;
this.focus = source.focus;
this.aspect = source.aspect;
this.view = source.view === null ? null : Object.assign( {}, source.view );
this.filmGauge = source.filmGauge;
this.filmOffset = source.filmOffset;
return this;
}
/**
* Sets the FOV by focal length in respect to the current {@link PerspectiveCamera#filmGauge}.
*
* The default film gauge is 35, so that the focal length can be specified for
* a 35mm (full frame) camera.
*
* @param {number} focalLength - Values for focal length and film gauge must have the same unit.
*/
setFocalLength( focalLength ) {
/** see {@link http://www.bobatkins.com/photography/technical/field_of_view.html} */
const vExtentSlope = 0.5 * this.getFilmHeight() / focalLength;
this.fov = RAD2DEG * 2 * Math.atan( vExtentSlope );
this.updateProjectionMatrix();
}
/**
* Returns the focal length from the current {@link PerspectiveCamera#fov} and
* {@link PerspectiveCamera#filmGauge}.
*
* @return {number} The computed focal length.
*/
getFocalLength() {
const vExtentSlope = Math.tan( DEG2RAD * 0.5 * this.fov );
return 0.5 * this.getFilmHeight() / vExtentSlope;
}
/**
* Returns the current vertical field of view angle in degrees considering {@link PerspectiveCamera#zoom}.
*
* @return {number} The effective FOV.
*/
getEffectiveFOV() {
return RAD2DEG * 2 * Math.atan(
Math.tan( DEG2RAD * 0.5 * this.fov ) / this.zoom );
}
/**
* Returns the width of the image on the film. If {@link PerspectiveCamera#aspect} is greater than or
* equal to one (landscape format), the result equals {@link PerspectiveCamera#filmGauge}.
*
* @return {number} The film width.
*/
getFilmWidth() {
// film not completely covered in portrait format (aspect < 1)
return this.filmGauge * Math.min( this.aspect, 1 );
}
/**
* Returns the height of the image on the film. If {@link PerspectiveCamera#aspect} is greater than or
* equal to one (landscape format), the result equals {@link PerspectiveCamera#filmGauge}.
*
* @return {number} The film width.
*/
getFilmHeight() {
// film not completely covered in landscape format (aspect > 1)
return this.filmGauge / Math.max( this.aspect, 1 );
}
/**
* Computes the 2D bounds of the camera's viewable rectangle at a given distance along the viewing direction.
* Sets `minTarget` and `maxTarget` to the coordinates of the lower-left and upper-right corners of the view rectangle.
*
* @param {number} distance - The viewing distance.
* @param {Vector2} minTarget - The lower-left corner of the view rectangle is written into this vector.
* @param {Vector2} maxTarget - The upper-right corner of the view rectangle is written into this vector.
*/
getViewBounds( distance, minTarget, maxTarget ) {
_v3.set( - 1, - 1, 0.5 ).applyMatrix4( this.projectionMatrixInverse );
minTarget.set( _v3.x, _v3.y ).multiplyScalar( - distance / _v3.z );
_v3.set( 1, 1, 0.5 ).applyMatrix4( this.projectionMatrixInverse );
maxTarget.set( _v3.x, _v3.y ).multiplyScalar( - distance / _v3.z );
}
/**
* Computes the width and height of the camera's viewable rectangle at a given distance along the viewing direction.
*
* @param {number} distance - The viewing distance.
* @param {Vector2} target - The target vector that is used to store result where x is width and y is height.
* @returns {Vector2} The view size.
*/
getViewSize( distance, target ) {
this.getViewBounds( distance, _minTarget, _maxTarget );
return target.subVectors( _maxTarget, _minTarget );
}
/**
* Sets an offset in a larger frustum. This is useful for multi-window or
* multi-monitor/multi-machine setups.
*
* For example, if you have 3x2 monitors and each monitor is 1920x1080 and
* the monitors are in grid like this
*```
* +---+---+---+
* | A | B | C |
* +---+---+---+
* | D | E | F |
* +---+---+---+
*```
* then for each monitor you would call it like this:
*```js
* const w = 1920;
* const h = 1080;
* const fullWidth = w * 3;
* const fullHeight = h * 2;
*
* // --A--
* camera.setViewOffset( fullWidth, fullHeight, w * 0, h * 0, w, h );
* // --B--
* camera.setViewOffset( fullWidth, fullHeight, w * 1, h * 0, w, h );
* // --C--
* camera.setViewOffset( fullWidth, fullHeight, w * 2, h * 0, w, h );
* // --D--
* camera.setViewOffset( fullWidth, fullHeight, w * 0, h * 1, w, h );
* // --E--
* camera.setViewOffset( fullWidth, fullHeight, w * 1, h * 1, w, h );
* // --F--
* camera.setViewOffset( fullWidth, fullHeight, w * 2, h * 1, w, h );
* ```
*
* Note there is no reason monitors have to be the same size or in a grid.
*
* @param {number} fullWidth - The full width of multiview setup.
* @param {number} fullHeight - The full height of multiview setup.
* @param {number} x - The horizontal offset of the subcamera.
* @param {number} y - The vertical offset of the subcamera.
* @param {number} width - The width of subcamera.
* @param {number} height - The height of subcamera.
*/
setViewOffset( fullWidth, fullHeight, x, y, width, height ) {
this.aspect = fullWidth / fullHeight;
if ( this.view === null ) {
this.view = {
enabled: true,
fullWidth: 1,
fullHeight: 1,
offsetX: 0,
offsetY: 0,
width: 1,
height: 1
};
}
this.view.enabled = true;
this.view.fullWidth = fullWidth;
this.view.fullHeight = fullHeight;
this.view.offsetX = x;
this.view.offsetY = y;
this.view.width = width;
this.view.height = height;
this.updateProjectionMatrix();
}
/**
* Removes the view offset from the projection matrix.
*/
clearViewOffset() {
if ( this.view !== null ) {
this.view.enabled = false;
}
this.updateProjectionMatrix();
}
/**
* Updates the camera's projection matrix. Must be called after any change of
* camera properties.
*/
updateProjectionMatrix() {
const near = this.near;
let top = near * Math.tan( DEG2RAD * 0.5 * this.fov ) / this.zoom;
let height = 2 * top;
let width = this.aspect * height;
let left = - 0.5 * width;
const view = this.view;
if ( this.view !== null && this.view.enabled ) {
const fullWidth = view.fullWidth,
fullHeight = view.fullHeight;
left += view.offsetX * width / fullWidth;
top -= view.offsetY * height / fullHeight;
width *= view.width / fullWidth;
height *= view.height / fullHeight;
}
const skew = this.filmOffset;
if ( skew !== 0 ) left += near * skew / this.getFilmWidth();
this.projectionMatrix.makePerspective( left, left + width, top, top - height, near, this.far, this.coordinateSystem );
this.projectionMatrixInverse.copy( this.projectionMatrix ).invert();
}
toJSON( meta ) {
const data = super.toJSON( meta );
data.object.fov = this.fov;
data.object.zoom = this.zoom;
data.object.near = this.near;
data.object.far = this.far;
data.object.focus = this.focus;
data.object.aspect = this.aspect;
if ( this.view !== null ) data.object.view = Object.assign( {}, this.view );
data.object.filmGauge = this.filmGauge;
data.object.filmOffset = this.filmOffset;
return data;
}
}
export { PerspectiveCamera };