This disclosure describes techniques for simplifying depth inter mode coding in a three-dimensional (3D) video coding process, such as 3D-HEVC. The techniques include generating a motion parameter candidate list, e.g., merging candidate list, for a current depth prediction unit (PU). In some examples, the described techniques include determining that a sub-PU motion parameter inheritance (MPI) motion parameter candidate is unavailable for inclusion in the motion parameter candidate list for the current depth PU if motion parameters of a co-located texture block to a representative block of the current depth PU are unavailable. In some examples, the described techniques include deriving a sub-PU MPI candidate for inclusion in the motion parameter candidate list for the current depth PU only if a partition mode of the current depth PU is 2N×2N.