_renderBundle( bundle, sceneRef, lightsNode ) {

		const { bundleGroup, camera, renderList } = bundle;

		const renderContext = this._currentRenderContext;

		//

		const renderBundle = this._bundles.get( bundleGroup, camera );
		const renderBundleData = this.backend.get( renderBundle );

		if ( renderBundleData.renderContexts === undefined ) renderBundleData.renderContexts = new Set();

		//

		const needsUpdate = bundleGroup.version !== renderBundleData.version;
		const renderBundleNeedsUpdate = renderBundleData.renderContexts.has( renderContext ) === false || needsUpdate;

		renderBundleData.renderContexts.add( renderContext );

		if ( renderBundleNeedsUpdate ) {

			this.backend.beginBundle( renderContext );

			if ( renderBundleData.renderObjects === undefined || needsUpdate ) {

				renderBundleData.renderObjects = [];

			}

			this._currentRenderBundle = renderBundle;

			const {
				transparentDoublePass: transparentDoublePassObjects,
				transparent: transparentObjects,
				opaque: opaqueObjects
			} = renderList;

			if ( this.opaque === true && opaqueObjects.length > 0 ) this._renderObjects( opaqueObjects, camera, sceneRef, lightsNode );
			if ( this.transparent === true && transparentObjects.length > 0 ) this._renderTransparents( transparentObjects, transparentDoublePassObjects, camera, sceneRef, lightsNode );

			this._currentRenderBundle = null;

			//

			this.backend.finishBundle( renderContext, renderBundle );

			renderBundleData.version = bundleGroup.version;

		} else {

			const { renderObjects } = renderBundleData;

			for ( let i = 0, l = renderObjects.length; i < l; i ++ ) {

				const renderObject = renderObjects[ i ];

				if ( this._nodes.needsRefresh( renderObject ) ) {

					this._nodes.updateBefore( renderObject );

					this._nodes.updateForRender( renderObject );
					this._bindings.updateForRender( renderObject );

					this._nodes.updateAfter( renderObject );

				}

			}

		}

		this.backend.addBundle( renderContext, renderBundle );

	}
Renders the given render bundle.

@private
@param {Object} bundle - Render bundle data.
@param {Scene} sceneRef - The scene the render bundle belongs to.
@param {LightsNode} lightsNode - The lights node.