Opening a chest using the physics code in Penumbra: Overture
|Platform||Windows, Mac OS X, Linux|
|License||Proprietary/GNU General Public License|
The HPL Engine is a 3D game engine created by Frictional Games. The engine, named after the initials of horror author H. P. Lovecraft, was started in December 2004, as a thesis job for a 2D platform game "Energetic", released in 2005. The functionality for 3D games was added later, which culminated in Penumbra Tech Demo in 2006. In 2010, the first version of the engine (HPL1) together with Penumbra: Overture was released as open source under the GPL license, after the Humble Indie Bundle promotion finished.
HPL is a cross-platform game engine which is compatible with the OpenGL, OpenAL, and Newton Game Dynamics libraries. One of the engine's defining features is its ability for advanced object interaction through the use of Newton's physics code.
HPL Engine 1
The first incarnation of HPL was demonstrated by the original Penumbra Tech Demo. The developers admitted to making significant modifications of the original engine to accommodate the 3D graphics in this game, "The engine is built from an engine created when making a thesis job which resulted in the platform game Energetic. Before moving into the 3rd dimension I made some cleanup of the engine (which was quite rushed in some places) and started to add a base for 3D rendering. I would not say that the original 2D engine was modified to add 3D, but rather a 3D layer was added so all of the 2D stuff is still there. It is still possible to make a 2D tile game using our engine." Another innovative feature of the engine was its ability to have static as well as dynamic shadows, allowing people with less powerful video cards to still experience some shadowing effects without the need of having to dynamically render them.
Penumbra: Overture was released as part of the Humble Indie Bundle, and when the Bundle made more than $1 million, Overture was released under the GNU General Public License. This release included the game engine and development tools.
The following games use this incarnation of HPL:
HPL Engine 2
HPL 2 is the engine being showcased in Frictional's game series Amnesia, which has various new features and advancements. While HPL 1 used a portal system to do occlusion culling (a process which determines what objects should not be drawn), HPL 2 uses a dynamic culling system technique called Coherent Hierarchical Culling. HPL 1 also used stencil shadow volumes for shadowing while HPL 2 uses shadow mapping. The engine also boasts new effects such as Screen Space Ambient Occlusion, proper decals and a new rendering technique called Deferred shading. This causes HPL 2 to have higher systems requirements than the previous HPL Engine.
The following games use this incarnation of HPL:
HPL Engine 3
- Global sunlight along with shadows, allowing fully lit outdoor scenes
- In-engine terrain generation and dynamic terrain LOD
- HDR lighting with filmic tone mapping
- HPSL shading language
- Depth of field
- Beaton, Connor (9 November 2011). "Jens Nilsson Interview: Amnesia & The Future". Zcint.co.uk. Retrieved 24 July 2013.
- "Penumbra: Overture goes Open Source!". Frictional Games Blogspot. 14 May 2010. Retrieved 22 August 2010.
- Jong, Philip (25 December 2007). "Jens Nilsson, Thomas Grip, TJ Jubert - Frictional Games". Adventure Classic Gaming. Retrieved 24 July 2013.
- "HPL1". Mod DB. Retrieved 29 June 2010.
- "HPL2". Mod DB. Retrieved 24 July 2013.
- Fulks, Bill. "Why You Should Add Penumbra Games to Your Horror PC Game Collection". Alteredgamer.com. Retrieved 24 July 2013.
- Martin, Joe (20 February 2008). "Penumbra: Black Plague". bit-tech. Retrieved 29 August 2010.
- Senior, Tom (23 December 2010). "Humble Indie Bundle 2 now includes Humble Indie Bundle 1 games". PC Gamer. Retrieved 24 July 2013.
- "Penumbra: Overture, HPL1 Engine and OALWrapper released as open source". Frictionalgames.com. 14 May 2010. Retrieved 29 June 2010.
- "Interview With Frictional Games – Amnesia". Linuxgamingnews.org. 25 November 2009. Retrieved 30 June 2010.
- Grayson, Nathan (11 September 2012). "Amnesia Devs Hint At Next Project, Dismiss Piracy". Rock, Paper, Shotgun. Retrieved 24 July 2013.
- "About". Frictionalgames.com. Retrieved 24 July 2013.
- "Tech feature: Sunlight with Shadows". Frictional Games Blogspot. 13 October 2010. Retrieved 13 October 2010.
- "Tech Feature: Terrain geometry". Frictional Games Blogspot. 4 November 2010. Retrieved 7 November 2010.
- "Tech Feature: HDR Lighting". Frictional Games Blogspot. 7 September 2012. Retrieved 24 July 2013.
- "Tech Feature: HPSL Shading Language". Frictional Games Blogspot. 22 April 2014. Retrieved 22 April 2014.
- "People of Frictional: Peter Wester". Frictional Games Blogspot. 14 August 2014. Retrieved 15 August 2014.