three.js/src/cameras/CubeCamera.js

/**
 * Camera for rendering cube maps
 *	- renders scene into axis-aligned cube
 *
 * @author alteredq / http://alteredqualia.com/
 */

THREE.CubeCamera = function ( near, far, cubeResolution ) {

	THREE.Object3D.call( this );

	this.type = 'CubeCamera';

	var fov = 90, aspect = 1;

	var cameraPX = new THREE.PerspectiveCamera( fov, aspect, near, far );
	cameraPX.up.set( 0, - 1, 0 );
	cameraPX.lookAt( new THREE.Vector3( 1, 0, 0 ) );
	this.add( cameraPX );

	var cameraNX = new THREE.PerspectiveCamera( fov, aspect, near, far );
	cameraNX.up.set( 0, - 1, 0 );
	cameraNX.lookAt( new THREE.Vector3( - 1, 0, 0 ) );
	this.add( cameraNX );

	var cameraPY = new THREE.PerspectiveCamera( fov, aspect, near, far );
	cameraPY.up.set( 0, 0, 1 );
	cameraPY.lookAt( new THREE.Vector3( 0, 1, 0 ) );
	this.add( cameraPY );

	var cameraNY = new THREE.PerspectiveCamera( fov, aspect, near, far );
	cameraNY.up.set( 0, 0, - 1 );
	cameraNY.lookAt( new THREE.Vector3( 0, - 1, 0 ) );
	this.add( cameraNY );

	var cameraPZ = new THREE.PerspectiveCamera( fov, aspect, near, far );
	cameraPZ.up.set( 0, - 1, 0 );
	cameraPZ.lookAt( new THREE.Vector3( 0, 0, 1 ) );
	this.add( cameraPZ );

	var cameraNZ = new THREE.PerspectiveCamera( fov, aspect, near, far );
	cameraNZ.up.set( 0, - 1, 0 );
	cameraNZ.lookAt( new THREE.Vector3( 0, 0, - 1 ) );
	this.add( cameraNZ );

	this.renderTarget = new THREE.WebGLRenderTargetCube( cubeResolution, cubeResolution, { format: THREE.RGBFormat, magFilter: THREE.LinearFilter, minFilter: THREE.LinearFilter } );

	this.updateCubeMap = function ( renderer, scene ) {

		var renderTarget = this.renderTarget;
		var generateMipmaps = renderTarget.generateMipmaps;

		renderTarget.generateMipmaps = false;

		renderTarget.activeCubeFace = 0;
		renderer.render( scene, cameraPX, renderTarget );

		renderTarget.activeCubeFace = 1;
		renderer.render( scene, cameraNX, renderTarget );

		renderTarget.activeCubeFace = 2;
		renderer.render( scene, cameraPY, renderTarget );

		renderTarget.activeCubeFace = 3;
		renderer.render( scene, cameraNY, renderTarget );

		renderTarget.activeCubeFace = 4;
		renderer.render( scene, cameraPZ, renderTarget );

		renderTarget.generateMipmaps = generateMipmaps;

		renderTarget.activeCubeFace = 5;
		renderer.render( scene, cameraNZ, renderTarget );

	};

};

THREE.CubeCamera.prototype = Object.create( THREE.Object3D.prototype );
THREE.CubeCamera.prototype.constructor = THREE.CubeCamera;