Correct!
Because Odd-Eyes Gravity Dragon has a summoning condition, being that it needs to be first ritual summoned, it cannot be summoned from the deck with Arc Pendulum Dragon. Once you have properly summoned it however, as long as it is remains in a location that is public knowledge (The field, Graveyard, or face-up banished), it will remember that it was properly summoned and thus viable for revival with a card effect.
Thank you for marking the answer as the solution. This threat will close in 24 hours from the last post.
If you have any other questions or scenarios where you believe Omega is not acting as it should, feel free to make a new topic and we will do our best to help you!