Pixar’s cinematic magic continues unabated with “Finding Dory,” the recent sequel to 2003’s “Finding Nemo.” Ellen DeGeneres returns as the voice of the forgetful blue tang, who embarks on a heartwarming journey to find her long-lost parents. The visuals feature jaw-dropping scenes such as an octopus behind the wheel of a careering truck. Among many extras, Tuesday’s Blu-ray adds the Pixar short “Piper,” a delightful look at a young sandpiper’s first foray into foraging.