A device for processing video data includes a memory configured to store video data and one or more processors implemented in circuitry. The one or more processors are configured to select two or more subblocks of one or more blocks of video data and generate an affine motion model for a current block of video data using a subblock motion vector from each of the two or more subblocks as control-point motion vectors for the current block. The one or more processors are further configured to determine one or more prediction blocks based on the affine motion model and predict the current block with the one or more prediction blocks.