Frictional Games have announced that they've now open source the game engine behind Amnesia: The Dark Descent and Amnesia: A Machine for Pigs as open source under the GPL.
It's worth noting, that like a lot of open source releases this is only the code and not all the other media assets. A great way to do it, as the original developer earns their monies as people need to buy it to run it but it can be kept alive for generations to come, ported to new platforms and more. Frictional are no strangers to open source, as they also put up the HPL1 game engine that powered the Penumbra Series in the same way many years ago.
With the announcement, they mentioned they had been wanting to do this for some time but things kept coming up, so with The Dark Descent recently turning 10 (yes, 10 years!) it was time. They do this to help the modding community, and help others to learn from it too - they noted how it's "a testament that it is possible to do this sort of thing, even with a very limited team".
Some of the interesting features the HPL2 game engine supports are:
- Shadow mapping with soft edges.
- Realtime visibility culling system that also works for dynamic objects.
- Automatic render batch system of static objects.
- Deferred shading system.
- A full editor with lots of interesting feature that such as picking algorithms and view fitting.
- Very simple state machine AI that still gives rise to fairly interesting and intelligent agents.
- Fairly advanced system for physics sounds.
- Physics based interaction system.
- Own sound system implemented using OpenAL
- Lots of other basic rendering and gameplay tech all implemented in an a coherent engine structure
A lot of it is pretty old tech, however it's still great to see more open source game engines that have all of it together. I think this is how it should be done anyway. Once a developer is properly finished with a game and moved on, having it open like this has so many benefits.
Source code links:
Links to buy copies for the assets / to play them:
- Amnesia: The Dark Descent - Humble Store, GOG, Steam
- Amnesia: A Machine For Pigs - Humble Store, GOG, Steam
If you missed it their next game Amnesia: Rebirth releases on October 20.