Devices, systems and methods for digital video coding, which includes using default motion candidates for video coding, are described. An exemplary method for video processing includes determining, for a conversion between a block of a video and a bitstream representation of the video, weights to use for a weighted average of prediction samples along an edge of two partitions of the block. The two partitions are generated according to a geometry partition mode, and the weights are selected from a first weighting factor group that at least one of the weights is equal to 0 or 1. The method also includes performing the conversion based on the determining.