Systems, methods, and instrumentalities are disclosed that relate to the processing of a media container file associated with 3D video data. The media container file may indicate that certain video-based point cloud compression (V-PCC) component tracks may be played together as a playout group. These V-PCG component tracks may represent respective encoded versions of one or more V-PCC components, and a video decoding device may play the tracks together in response to determining that the tracks belong to the same playout track group. The video decoding device may also determine from the media container file that certain PCC component tracks include tile groups that correspond to different objects in a point cloud or different parts of a same object in the point cloud. The video decoding device may decode these tile groups independently from each other so that a subset of the objects or parts of the point cloud may be accessed without also accessing the rest of the objects or parts.