three
Version:
JavaScript 3D library
275 lines (208 loc) • 8.15 kB
JavaScript
import {
LinearFilter,
MathUtils,
Matrix3,
NearestFilter,
PerspectiveCamera,
RGBAFormat,
ShaderMaterial,
Vector3,
WebGLRenderTarget
} from 'three';
import { FullScreenQuad } from '../postprocessing/Pass.js';
import { frameCorners } from '../utils/CameraUtils.js';
const _cameraL = /*@__PURE__*/ new PerspectiveCamera();
const _cameraR = /*@__PURE__*/ new PerspectiveCamera();
// Reusable vectors for screen corner calculations
const _eyeL = /*@__PURE__*/ new Vector3();
const _eyeR = /*@__PURE__*/ new Vector3();
const _screenCenter = /*@__PURE__*/ new Vector3();
const _screenBottomLeft = /*@__PURE__*/ new Vector3();
const _screenBottomRight = /*@__PURE__*/ new Vector3();
const _screenTopLeft = /*@__PURE__*/ new Vector3();
const _right = /*@__PURE__*/ new Vector3();
const _up = /*@__PURE__*/ new Vector3();
const _forward = /*@__PURE__*/ new Vector3();
/**
* A class that creates an anaglyph effect using physically-correct
* off-axis stereo projection.
*
* This implementation uses CameraUtils.frameCorners() to align stereo
* camera frustums to a virtual screen plane, providing accurate depth
* perception with zero parallax at the plane distance.
*
* Note that this class can only be used with {@link WebGLRenderer}.
* When using {@link WebGPURenderer}, use {@link AnaglyphPassNode}.
*
* @three_import import { AnaglyphEffect } from 'three/addons/effects/AnaglyphEffect.js';
*/
class AnaglyphEffect {
/**
* Constructs a new anaglyph effect.
*
* @param {WebGLRenderer} renderer - The renderer.
* @param {number} width - The width of the effect in physical pixels.
* @param {number} height - The height of the effect in physical pixels.
*/
constructor( renderer, width = 512, height = 512 ) {
// Dubois matrices from https://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.7.6968&rep=rep1&type=pdf#page=4
this.colorMatrixLeft = new Matrix3().fromArray( [
0.456100, - 0.0400822, - 0.0152161,
0.500484, - 0.0378246, - 0.0205971,
0.176381, - 0.0157589, - 0.00546856
] );
this.colorMatrixRight = new Matrix3().fromArray( [
- 0.0434706, 0.378476, - 0.0721527,
- 0.0879388, 0.73364, - 0.112961,
- 0.00155529, - 0.0184503, 1.2264
] );
/**
* The interpupillary distance (eye separation) in world units.
* Typical human IPD is 0.064 meters (64mm).
*
* @type {number}
* @default 0.064
*/
this.eyeSep = 0.064;
/**
* The distance in world units from the viewer to the virtual
* screen plane where zero parallax (screen depth) occurs.
* Objects at this distance appear at the screen surface.
* Objects closer appear in front of the screen (negative parallax).
* Objects further appear behind the screen (positive parallax).
*
* The screen dimensions are derived from the camera's FOV and aspect ratio
* at this distance, ensuring the stereo view matches the camera's field of view.
*
* @type {number}
* @default 0.5
*/
this.planeDistance = 0.5;
const _params = { minFilter: LinearFilter, magFilter: NearestFilter, format: RGBAFormat };
const _renderTargetL = new WebGLRenderTarget( width, height, _params );
const _renderTargetR = new WebGLRenderTarget( width, height, _params );
_cameraL.layers.enable( 1 );
_cameraR.layers.enable( 2 );
const _material = new ShaderMaterial( {
uniforms: {
'mapLeft': { value: _renderTargetL.texture },
'mapRight': { value: _renderTargetR.texture },
'colorMatrixLeft': { value: this.colorMatrixLeft },
'colorMatrixRight': { value: this.colorMatrixRight }
},
vertexShader: [
'varying vec2 vUv;',
'void main() {',
' vUv = vec2( uv.x, uv.y );',
' gl_Position = projectionMatrix * modelViewMatrix * vec4( position, 1.0 );',
'}'
].join( '\n' ),
fragmentShader: [
'uniform sampler2D mapLeft;',
'uniform sampler2D mapRight;',
'varying vec2 vUv;',
'uniform mat3 colorMatrixLeft;',
'uniform mat3 colorMatrixRight;',
'void main() {',
' vec2 uv = vUv;',
' vec4 colorL = texture2D( mapLeft, uv );',
' vec4 colorR = texture2D( mapRight, uv );',
' vec3 color = clamp(',
' colorMatrixLeft * colorL.rgb +',
' colorMatrixRight * colorR.rgb, 0., 1. );',
' gl_FragColor = vec4(',
' color.r, color.g, color.b,',
' max( colorL.a, colorR.a ) );',
' #include <tonemapping_fragment>',
' #include <colorspace_fragment>',
'}'
].join( '\n' )
} );
const _quad = new FullScreenQuad( _material );
/**
* Resizes the effect.
*
* @param {number} width - The width of the effect in logical pixels.
* @param {number} height - The height of the effect in logical pixels.
*/
this.setSize = function ( width, height ) {
renderer.setSize( width, height );
const pixelRatio = renderer.getPixelRatio();
_renderTargetL.setSize( width * pixelRatio, height * pixelRatio );
_renderTargetR.setSize( width * pixelRatio, height * pixelRatio );
};
/**
* When using this effect, this method should be called instead of the
* default {@link WebGLRenderer#render}.
*
* @param {Object3D} scene - The scene to render.
* @param {Camera} camera - The camera.
*/
this.render = function ( scene, camera ) {
const currentRenderTarget = renderer.getRenderTarget();
if ( scene.matrixWorldAutoUpdate === true ) scene.updateMatrixWorld();
if ( camera.parent === null && camera.matrixWorldAutoUpdate === true ) camera.updateMatrixWorld();
// Get the camera's local coordinate axes from its world matrix
camera.matrixWorld.extractBasis( _right, _up, _forward );
_right.normalize();
_up.normalize();
_forward.normalize();
// Calculate eye positions
const halfSep = this.eyeSep / 2;
_eyeL.copy( camera.position ).addScaledVector( _right, - halfSep );
_eyeR.copy( camera.position ).addScaledVector( _right, halfSep );
// Calculate screen center (at planeDistance in front of the camera center)
_screenCenter.copy( camera.position ).addScaledVector( _forward, - this.planeDistance );
// Calculate screen dimensions from camera FOV and aspect ratio
const halfHeight = this.planeDistance * Math.tan( MathUtils.DEG2RAD * camera.fov / 2 );
const halfWidth = halfHeight * camera.aspect;
// Calculate screen corners
_screenBottomLeft.copy( _screenCenter )
.addScaledVector( _right, - halfWidth )
.addScaledVector( _up, - halfHeight );
_screenBottomRight.copy( _screenCenter )
.addScaledVector( _right, halfWidth )
.addScaledVector( _up, - halfHeight );
_screenTopLeft.copy( _screenCenter )
.addScaledVector( _right, - halfWidth )
.addScaledVector( _up, halfHeight );
// Set up left eye camera
_cameraL.position.copy( _eyeL );
_cameraL.near = camera.near;
_cameraL.far = camera.far;
frameCorners( _cameraL, _screenBottomLeft, _screenBottomRight, _screenTopLeft, true );
_cameraL.matrixWorld.compose( _cameraL.position, _cameraL.quaternion, _cameraL.scale );
_cameraL.matrixWorldInverse.copy( _cameraL.matrixWorld ).invert();
// Set up right eye camera
_cameraR.position.copy( _eyeR );
_cameraR.near = camera.near;
_cameraR.far = camera.far;
frameCorners( _cameraR, _screenBottomLeft, _screenBottomRight, _screenTopLeft, true );
_cameraR.matrixWorld.compose( _cameraR.position, _cameraR.quaternion, _cameraR.scale );
_cameraR.matrixWorldInverse.copy( _cameraR.matrixWorld ).invert();
// Render left eye
renderer.setRenderTarget( _renderTargetL );
renderer.clear();
renderer.render( scene, _cameraL );
// Render right eye
renderer.setRenderTarget( _renderTargetR );
renderer.clear();
renderer.render( scene, _cameraR );
// Composite anaglyph
renderer.setRenderTarget( null );
_quad.render( renderer );
renderer.setRenderTarget( currentRenderTarget );
};
/**
* Frees internal resources. This method should be called
* when the effect is no longer required.
*/
this.dispose = function () {
_renderTargetL.dispose();
_renderTargetR.dispose();
_material.dispose();
_quad.dispose();
};
}
}
export { AnaglyphEffect };