getGroupContext( clippingGroup ) {

		if ( this.shadowPass && ! clippingGroup.clipShadows ) return this;

		let context = this.clippingGroupContexts.get( clippingGroup );

		if ( context === undefined ) {

			context = new ClippingContext( this );
			this.clippingGroupContexts.set( clippingGroup, context );

		}

		context.update( this, clippingGroup );

		return context;

	}
Returns a clipping context for the given clipping group.

@param {ClippingGroup} clippingGroup - The clipping group.
@return {ClippingContext} The clipping context.