Yes Chrisdmd, that is how it’s done. Once you’ve selected the background around the house and made it black (transparent) just hold down the “Shift” and “Ctrl” keys together and press the “I” key to invert the selection then make that white (opaque or visible). You then save that image to whatever format your 3D program uses (it could be any of several formats) and use that black/white image as the alpha file. It’s usually used in conjunction with the original image thereby being the same size and showing through only the house of the original picture without its surroundings. To unselect you simply press “Ctrl” + “D”.

Quest