A U.S. jury in Texas on Wednesday ordered Facebook Inc., its virtual reality unit Oculus, and other defendants to pay a combined $500 million to ZeniMax Media Inc., a video game publisher that says Oculus stole its technology. The jury in federal court in Dallas found Oculus, which Facebook acquired for about $2 billion in 2014, used ZeniMax’s computer code to launch the Rift virtual-reality headset.