Monetizing Your Game - Learning Unreal Engine iOS Game Development - page 170

Adding achievements
As leaderboards and achievements used to be discussed together as one topic, Epic has
done their best to make the Achievements process similar to the Leaderboard process,
which is as follows:
1. Use the Write Achievement Progress node.
2. Assign a value for Achievement Name , which represents the ID in iTunes Con-
nect.
3. Pass a Progress value to it if it is a progression achievement.
4. You don't have to use a user tag, but this value will be returned anyway on success
and on failure.
You can also use a similar node on the leaderboards to display the Game Center achieve-
ments screen by calling Show Platform Specific Achievements Screen . This too is named
Specific as it is used with Android to show the Google Play Achievements screen.
As leaderboards have the functionality to download the progress and get its values,
achievements have similar functionality too. However, as an achievement has a progress
and description and not just progress (unlike the leaderboard), achievements have four
nodes. The Cache Achievement node and the Cache Achievement Description node both
download and cache (save on the device) the achievement progress and description. So, if
the player has no Internet connection and still wants to display the achievements, they still
have a chance to display it offline with caching.