<!-- AVATAR-FORGE · part 61 -->
mera.updateCoordinateSystem(): Invalid coordinate system: ' + coordinateSystem );

		}

		for ( const camera of cameras ) {

			this.add( camera );

			camera.updateMatrixWorld();

		}

	}

	update( renderer, scene ) {

		if ( this.parent === null ) this.updateMatrixWorld();

		const { renderTarget, activeMipmapLevel } = this;

		if ( this.coordinateSystem !== renderer.coordinateSystem ) {

			this.coordinateSystem = renderer.coordinateSystem;

			this.updateCoordinateSystem();

		}

		const [ cameraPX, cameraNX, cameraPY, cameraNY, cameraPZ, cameraNZ ] = this.children;

		const currentRenderTarget = renderer.getRenderTarget();
		const currentActiveCubeFace = renderer.getActiveCubeFace();
		const currentActiveMipmapLevel = renderer.getActiveMipmapLevel();

		const currentXrEnabled = renderer.xr.enabled;

		renderer.xr.enabled = false;

		const generateMipmaps = renderTarget.texture.generateMipmaps;

		renderTarget.texture.generateMipmaps = false;

		renderer.setRenderTarget( renderTarget, 0, activeMipmapLevel );
		renderer.render( scene, cameraPX );

		renderer.setRenderTarget( renderTarget, 1, activeMipmapLevel );
		renderer.render( scene, cameraNX );

		renderer.setRenderTarget( renderTarget, 2, activeMipmapLevel );
		renderer.render( scene, cameraPY );

		renderer.setRenderTarget( renderTarget, 3, activeMipmapLevel );
		renderer.render( scene, cameraNY );

		renderer.setRenderTarget( renderTarget, 4, activeMipmapLevel );
		renderer.render( scene, cameraPZ );

		// mipmaps are generated during the last call of render()
		// at this point, all sides of the cube render target are defined

		renderTarget.texture.generateMipmaps = generateMipmaps;

		renderer.setRenderTarget( renderTarget, 5, activeMipmapLevel );
		renderer.render( scene, cameraNZ );

		renderer.setRenderTarget( currentRenderTarget, currentActiveCubeFace, currentActiveMipmapLevel );

		renderer.xr.enabled = currentXrEnabled;

		renderTarget.texture.needsPMREMUpdate = true;

	}

}

class CubeTexture extends Texture {

	constructor( images, mapping, wrapS, wrapT, magFilter, minFilter, format, type, anisotropy, colorSpace ) {

		images = images !== undefined ? images : [];
		mapping = mapping !== undefined ? mapping : CubeReflectionMapping;

		super( images, mapping, wrapS, wrapT, magFilter, minFilter, format, type, anisotropy, colorSpace );

		this.isCubeTexture = true;

		this.flipY = false;

	}

	get images() {

		return this.image;

	}

	set images( value ) {

		this.image = value;

	}

}

class WebGLCubeRenderTarget extends WebGLRenderTarget {

	constructor( size = 1, options = {} ) {

		super( size, size, options );

		this.isWebGLCubeRenderTarget = true;

		const image = { width: size, height: size, depth: 1 };
		const images = [ image, image, image, image, image, image ];

		this.texture = new CubeTexture( images, options.mapping, options.wrapS, options.wrapT, options.magFilter, options.minFilter, options.format, options.type, options.anisotropy, options.colorSpace );

		// By convention -- likely based on the RenderMan spec from the 1990's -- cube maps are specified by WebGL (and three.js)
		// in a coordinate system in which positive-x is to the right when looking up the positive-z axis -- in other words,
		// in a left-handed coordinate system. By continuing this convention, preexisting cube maps continued to render correctly.

		// three.js uses a right-handed coordinate system. So environment maps used in three.js appear to have px and nx swapped
		// and the flag isRenderTargetTexture controls this conversion. The flip is not required when using WebGLCubeRenderTarget.texture
		// as a cube texture (this is detected when isRenderTargetTexture is set to true for cube textures).

		this.texture.isRenderTargetTexture = true;

		this.texture.generateMipmaps = options.generateMipmaps !== undefined ? options.generateMipmaps : false;
		this.texture.minFilter = options.minFilter !== undefined ? options.minFilter : LinearFilter;

	}

	fromEquirectangularTexture( renderer, texture ) {

		this.texture.type = texture.type;
		this.texture.colorSpace = texture.colorSpace;

		this.texture.generateMipmaps = texture.generateMipmaps;
		this.texture.minFilter = texture.minFilter;
		this.texture.magFilter = texture.magFilter;

		const shader = {

			uniforms: {
				tEquirect: { value: null },
			},

			vertexShader: /* glsl */`

				varying vec3 vWorldDirection;

				vec3 transformDirection( in vec3 dir, in mat4 matrix ) {

					return normalize( ( matrix * vec4( dir, 0.0 ) ).xyz );

				}

				void main() {

					vWorldDirection = transformDirection( position, modelMatrix );

					#include <begin_vertex>
					#include <project_vertex>

				}
			`,

			fragmentShader: /* glsl */`

				uniform sampler2D tEquirect;

				varying vec3 vWorldDirection;

				#include <common>

				void main() {

					vec3 direction = normalize( vWorldDirection );

					vec2 sampleUV = equirectUv( direction );

					gl_FragColor = texture2D(