1. A method of coding three-dimensional (3D) video data, the method comprising: generating a list of merging candidates for coding a video block of the 3D video data, wherein a maximum number of merging candidates in the list of merging candidates is equal to 6 and generating the list of merging candidates comprises: determining whether a number of merging candidates in the list of merging candidates is less than 5; and in response to determining that the number of merging candidates in the list of merging candidates is less than 5: deriving one or more combined bi-predictive merging candidates, wherein each respective combined bi-predictive merging candidate of the one or more combined bi-predictive merging candidates corresponds to a respective pair of merging candidates already in the list of merging candidates, wherein the respective combined bi-predictive merging candidate is a combination of a motion vector of a first merging candidate of the respective pair and a motion vector of a second merging candidate of the respective pair, wherein the motion vector of the first merging candidate and the motion vector of the second merging candidate refer to pictures in different reference picture lists; and including the one or more combined bi-predictive merging candidates in the list of merging candidates.