WebGLRenderer: Simplify env map generation. (#23150)

src/renderers/webgl/WebGLCubeMaps.js

@@ -40,14 +40,10 @@ function WebGLCubeMaps( renderer ) {
 
 					if ( image && image.height > 0 ) {
 
-						const currentRenderTarget = renderer.getRenderTarget();
-
 						const renderTarget = new WebGLCubeRenderTarget( image.height / 2 );
 						renderTarget.fromEquirectangularTexture( renderer, texture );
 						cubemaps.set( texture, renderTarget );
 
-						renderer.setRenderTarget( currentRenderTarget );
-
 						texture.addEventListener( 'dispose', onTextureDispose );
 
 						return mapTextureMapping( renderTarget.texture, texture.mapping );

src/renderers/webgl/WebGLCubeUVMaps.js

@@ -30,15 +30,11 @@ function WebGLCubeUVMaps( renderer ) {
 
 					if ( ( isEquirectMap && image && image.height > 0 ) || ( isCubeMap && image && isCubeTextureComplete( image ) ) ) {
 
-						const currentRenderTarget = renderer.getRenderTarget();
-
 						if ( pmremGenerator === null ) pmremGenerator = new PMREMGenerator( renderer );
 
 						const renderTarget = isEquirectMap ? pmremGenerator.fromEquirectangular( texture ) : pmremGenerator.fromCubemap( texture );
 						cubeUVmaps.set( texture, renderTarget );
 
-						renderer.setRenderTarget( currentRenderTarget );
-
 						texture.addEventListener( 'dispose', onTextureDispose );
 
 						return renderTarget.texture;