              // Extract bright areas
                this.luminosityMaterial.uniforms.tMap.value = renderTarget.texture;
                this.screen.material = this.luminosityMaterial;
                renderer.setRenderTarget(renderTargetBright);
                renderer.render(this.screen, this.screenCamera);

                // Blur all the mips progressively
                let inputRenderTarget = renderTargetBright;

                for (let i = 0, l = this.nMips; i < l; i++) {
                    this