<!-- NEW3 — TEST 3 · THE RIVER'S JOURNEY · part 356 -->
rection = 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( tEquirect, sampleUV );

				}
			`
		};

		const geometry = new BoxGeometry( 5, 5, 5 );

		const material = new ShaderMaterial( {

			name: 'CubemapFromEquirect',

			uniforms: cloneUniforms( shader.uniforms ),
			vertexShader: shader.vertexShader,
			fragmentShader: shader.fragmentShader,
			side: BackSide,
			blending: NoBlending

		} );

		material.uniforms.tEquirect.value = texture;

		const mesh = new Mesh( geometry, material );

		const currentMinFilter = texture.minFilter;

		// Avoid blurred poles
		if ( texture.minFilter === LinearMipmapLinearFilter ) texture.minFilter = LinearFilter;

		const camera = new CubeCamera( 1, 10, this );
		camera.update( renderer, mesh );

		texture.minFilter = currentMinFilter;

		mesh.geometry.dispose();
		mesh.material.dispose();

		return this;

	}

	/**
	 * Clears this cube render target.
	 *
	 * @param {WebGLRenderer} renderer - The renderer.
	 * @param {boolean} [color=true] - Whether the color buffer should be cleared or not.
	 * @param {boolean} [depth=true] - Whether the depth buffer should be cleared or not.
	 * @param {boolean} [stencil=true] - Whether the stencil buffer should be cleared or not.
	 */
	clear( renderer, color = true, depth = true, stencil = true ) {

		const currentRenderTarget = renderer.getRenderTarget();

		for ( let i = 0; i < 6; i ++ ) {

			renderer.setRenderTarget( this, i );

			renderer.clear( color, depth, stencil );

		}

		renderer.setRenderTarget( currentRenderTarget );

	}

}

function WebGLEnvironments( renderer ) {

	let cubeMaps = new WeakMap();
	let pmremMaps = new WeakMap();

	let pmremGenerator = null;

	function get( texture, usePMREM = false ) {

		if ( texture === null || texture === undefined ) return null;

		if ( usePMREM ) {

			return getPMREM( texture );

		}

		return getCube( texture );

	}

	function getCube( texture ) {

		if ( texture && texture.isTexture ) {

			const mapping = texture.mapping;

			if ( mapping === EquirectangularReflectionMapping || mapping === EquirectangularRefractionMapping ) {

				if ( cubeMaps.has( texture ) ) {

					const cubemap = cubeMaps.get( texture ).texture;
					return mapTextureMapping( cubemap, texture.mapping );

				} else {

					const image = texture.image;

					if ( image && image.height > 0 ) {

						const renderTarget = new WebGLCubeRenderTarget( image.height );
						renderTarget.fromEquirectangularTexture( renderer, texture );
						cubeMaps.set( texture, renderTarget );

						texture.addEventListener( 'dispose', onCubemapDispose );

						return mapTextureMapping( renderTarget.texture, texture.mapping );

					} else {

						// image not yet ready. try the conversion next frame

						return null;

					}

				}

			}

		}

		return texture;

	}

	function getPMREM( texture ) {

		if ( texture && texture.isTexture ) {

			const mapping = texture.mapping;

			const isEquirectMap = ( mapping === EquirectangularReflectionMapping || mapping === EquirectangularRefractionMapping );
			const isCubeMap = ( mapping === CubeReflectionMapping || mapping === CubeRefractionMapping );

			// equirect/cube map to cubeUV conversion

			if ( isEquirectMap || isCubeMap ) {

				let renderTarget = pmremMaps.get( texture );

				const currentPMREMVersion = renderTarget !== undefined ? renderTarget.texture.pmremVersion : 0;

				if ( texture.isRenderTargetTexture && texture.pmremVersion !== currentPMREMVersion ) {

					if ( pmremGenerator === null ) pmremGenerator = new PMREMGenerator( renderer );

					renderTarget = isEquirectMap ? pmremGenerator.fromEquirectangular( texture, renderTarget ) : pmremGenerator.fromCubemap( texture, renderTarget );
					renderTarget.texture.pmremVersion = texture.pmremVersion;

					pmremMaps.set( texture, renderTarget );

					return renderTarget.texture;

				} else {

					if ( renderTarget !== undefined ) {

						return renderTarget.texture;

					} else {

						const image = texture.image;

						if ( ( isEquirectMap && image && image.height > 0 ) || ( isCubeMap && image && isCubeTextureComplete( image ) ) ) {

							if ( pmremGenerator === null ) pmremGenerator = new PMREMGenerator( renderer );

							renderTarget = isEquirectMap ? pmremGenerator.fromEquirectangular( texture ) : pmremGenerator.fromCubemap( texture );
							renderTarget.texture.pmremVersion = texture.pmremVersion;

							pmremMaps.set( texture, renderTarget );

							texture.addEventListener( 'dispose', onPMREMDispose );

							return renderTarget.texture;

						} else {

							// image not yet ready. try the conv