Upgrading to the Latest Engine Release

mtderosier · January 9, 2024, 6:40pm

Upgrading to the Latest Engine Release

Games with C++ code, like Lyra, require manual updates to work with new major Unreal Engine updates. Major engine upgrades may deprecate old features/settings and change functions/variables used by your project. Some game-specific code/data needs to be updated to work after the upgrade.

Let’s use Lyra as an example and follow these steps to update a game:

1. Start with a backup:

Back up your project before you attempt any upgradation.

2. Read Release Notes:

Review the release notes for the new engine version, note down any major changes and upgrade notes that may affect your game.

3. Create a New Git Branch:

Create a new branch in your git repository using:
```
git checkout -b upgradeBranch
```

4. Install the New Engine Version:

Download and install the new engine version. You can install this to a different directory than your current engine version for comparison.

5. Update the Lyra Starter Game Sample:

Download and install the new version of the Lyra Starter Game sample that matches the new engine version. Install this to a different directory for comparison.

6. Migration Guide:

Refer to the Unreal Engine 5 migration guide to check compatibility with the newest engine version.

7. Load Your Project:

Load your project in your C++ code editor and attempt to compile it. This will likely fail since it’s yet to be updated for the new engine version.

8. Fix Depreciation Warnings:

Resolve any depreciation warnings as per the instructions included in the depreciation message.

9. Fix Invalid or Missing Classes:

For errors about invalid or missing classes or structs, add a new #include line to the top of the file.

10. Update Virtual Function Overrides:

For errors about virtual function overrides, update the parameters of your overridden function in both the header and .cpp file.

11. Update Access to Invalid Variables:

For errors about invalid variables on a class or struct, use a different method of accessing that variable, usually by calling an accessor function like Get() or GetVariableName().

12. Stage, Commit & Push Changes:

Once your engine update is stable, add, commit, and push your changes to the upgradeBranch:

git add .
git commit -m "Upgraded to the latest engine version."
git push origin upgradeBranch

13. Merge the Changes:

If satisfied with the upgrades, create a pull request to merge your upgradeBranch into the main branch, or directly merge:
```
git checkout main
git merge upgradeBranch
```

14. Update Other Environments:

Lastly, pull the recent changes on all other environments to ensure they’re working with the updated code base:
```
git pull origin main
```

Following these steps will minimize potential risks while upgrading to a much recent Unreal Engine Version ensuring efficient code health.