fromEquirectangular( equirectangular ) {

    		return this._fromTexture( equirectangular );

    	}
Generates a PMREM from an equirectangular texture, which can be either LDR
(RGBFormat) or HDR (RGBEFormat). The ideal input image size is 1k (1024 x 512),
as this matches best with the 256 x 256 cubemap output.