<!-- AVATAR-FORGE · part 60 -->
---+---+---+
	 *
	 * then for each monitor you would call it like this
	 *
	 *   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.
	 */
	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();

	}

	clearViewOffset() {

		if ( this.view !== null ) {

			this.view.enabled = false;

		}

		this.updateProjectionMatrix();

	}

	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;

	}

}

const fov = - 90; // negative fov is not an error
const aspect = 1;

class CubeCamera extends Object3D {

	constructor( near, far, renderTarget ) {

		super();

		this.type = 'CubeCamera';

		this.renderTarget = renderTarget;
		this.coordinateSystem = null;
		this.activeMipmapLevel = 0;

		const cameraPX = new PerspectiveCamera( fov, aspect, near, far );
		cameraPX.layers = this.layers;
		this.add( cameraPX );

		const cameraNX = new PerspectiveCamera( fov, aspect, near, far );
		cameraNX.layers = this.layers;
		this.add( cameraNX );

		const cameraPY = new PerspectiveCamera( fov, aspect, near, far );
		cameraPY.layers = this.layers;
		this.add( cameraPY );

		const cameraNY = new PerspectiveCamera( fov, aspect, near, far );
		cameraNY.layers = this.layers;
		this.add( cameraNY );

		const cameraPZ = new PerspectiveCamera( fov, aspect, near, far );
		cameraPZ.layers = this.layers;
		this.add( cameraPZ );

		const cameraNZ = new PerspectiveCamera( fov, aspect, near, far );
		cameraNZ.layers = this.layers;
		this.add( cameraNZ );

	}

	updateCoordinateSystem() {

		const coordinateSystem = this.coordinateSystem;

		const cameras = this.children.concat();

		const [ cameraPX, cameraNX, cameraPY, cameraNY, cameraPZ, cameraNZ ] = cameras;

		for ( const camera of cameras ) this.remove( camera );

		if ( coordinateSystem === WebGLCoordinateSystem ) {

			cameraPX.up.set( 0, 1, 0 );
			cameraPX.lookAt( 1, 0, 0 );

			cameraNX.up.set( 0, 1, 0 );
			cameraNX.lookAt( - 1, 0, 0 );

			cameraPY.up.set( 0, 0, - 1 );
			cameraPY.lookAt( 0, 1, 0 );

			cameraNY.up.set( 0, 0, 1 );
			cameraNY.lookAt( 0, - 1, 0 );

			cameraPZ.up.set( 0, 1, 0 );
			cameraPZ.lookAt( 0, 0, 1 );

			cameraNZ.up.set( 0, 1, 0 );
			cameraNZ.lookAt( 0, 0, - 1 );

		} else if ( coordinateSystem === WebGPUCoordinateSystem ) {

			cameraPX.up.set( 0, - 1, 0 );
			cameraPX.lookAt( - 1, 0, 0 );

			cameraNX.up.set( 0, - 1, 0 );
			cameraNX.lookAt( 1, 0, 0 );

			cameraPY.up.set( 0, 0, 1 );
			cameraPY.lookAt( 0, 1, 0 );

			cameraNY.up.set( 0, 0, - 1 );
			cameraNY.lookAt( 0, - 1, 0 );

			cameraPZ.up.set( 0, - 1, 0 );
			cameraPZ.lookAt( 0, 0, 1 );

			cameraNZ.up.set( 0, - 1, 0 );
			cameraNZ.lookAt( 0, 0, - 1 );

		} else {

			throw new Error( 'THREE.CubeCa