HPL Engine
Encyclopedia
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 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.
, 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.
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:
s for shadowing while HPL 2 uses shadow mapping
. The engine also boasts new effects such as Screen Space Ambient Occlusion
and proper decals. This causes HPL 2 to have higher systems requirements than the previous HPL Engine.
The following games use this incarnation of HPL:
3D computer graphics
3D computer graphics are graphics that use a three-dimensional representation of geometric data that is stored in the computer for the purposes of performing calculations and rendering 2D images...
game engine
Game engine
A game engine is a system designed for the creation and development of video games. There are many game engines that are designed to work on video game consoles and personal computers...
created by Frictional Games
Frictional Games
Frictional Games is an independent video game company located in Helsingborg, Sweden. The developer comprises a small core team and is led by Thomas Grip and Jens Nilsson. Certain key roles such as Music and Narrative Design are performed by external staff like Mikko Tarmia and Tom Jubert,...
. The engine, named after the initials of horror author H. P. Lovecraft
H. P. Lovecraft
Howard Phillips Lovecraft --often credited as H.P. Lovecraft — was an American author of horror, fantasy and science fiction, especially the subgenre known as weird fiction....
, was started in 2004, as a thesis job for a 2D platform game
Platform game
A platform game is a video game characterized by requiring the player to jump to and from suspended platforms or over obstacles . It must be possible to control these jumps and to fall from platforms or miss jumps...
"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
Penumbra: Overture
Penumbra: Overture is the first in a series of episodic first-person adventure games developed by Swedish developer Frictional Games. It was originally intended as the first episode of a trilogy. With the announcement of the second episode, Penumbra: Black Plague, it was stated that the second game...
was released as open source
Open source
The term open source describes practices in production and development that promote access to the end product's source materials. Some consider open source a philosophy, others consider it a pragmatic methodology...
under the GPL license, after the Humble Indie Bundle
Humble Indie Bundle
The Humble Indie Bundles or Humble Bundles are a series of game bundles, that are sold and distributed online at a price determined by the purchaser. The games are multi-platform, DRM-free, and independently developed, and buyers can set the revenue split between the developers, charities and...
promotion finished.
Features
HPL is a cross-platform game engine which is compatible with the OpenGLOpenGL
OpenGL is a standard specification defining a cross-language, cross-platform API for writing applications that produce 2D and 3D computer graphics. The interface consists of over 250 different function calls which can be used to draw complex three-dimensional scenes from simple primitives. OpenGL...
, OpenAL
OpenAL
OpenAL is a cross-platform audio API. It is designed for efficient rendering of multichannel three dimensional positional audio. Its API style and conventions deliberately resemble those of OpenGL.- History :...
, and Newton Game Dynamics
Newton Game Dynamics
Newton Game Dynamics is an open source physics engine for realistically simulating rigid bodies in games and other real-time applications. Its solver is deterministic and not based on traditional LCP or iterative methods....
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
Humble Indie Bundle
The Humble Indie Bundles or Humble Bundles are a series of game bundles, that are sold and distributed online at a price determined by the purchaser. The games are multi-platform, DRM-free, and independently developed, and buyers can set the revenue split between the developers, charities and...
, and when the Bundle made more than $1 million, Overture was released under the GNU General Public License
GNU General Public License
The GNU General Public License is the most widely used free software license, originally written by Richard Stallman for the GNU Project....
. This release included the game engine and development tools.
The following games use this incarnation of HPL:
- Penumbra: OverturePenumbra: OverturePenumbra: Overture is the first in a series of episodic first-person adventure games developed by Swedish developer Frictional Games. It was originally intended as the first episode of a trilogy. With the announcement of the second episode, Penumbra: Black Plague, it was stated that the second game...
- Penumbra: Black PlaguePenumbra: Black PlaguePenumbra: Black Plague is the second installment of the Penumbra series of episodic computer games developed by Swedish developer Frictional Games. The story continues from the previous episode, Penumbra: Overture, showing the protagonist Philip moving away from the abandoned mine setting of the...
- Penumbra: RequiemPenumbra: RequiemPenumbra: Requiem is an expansion pack to the game Penumbra: Black Plague by Frictional Games.- Gameplay :Like the previous games, Requiem is an exploration-based adventure game that takes place from a first-person perspective and final installment of the main series...
HPL Engine 2
HPL 2 is the new engine being showcased in Frictional's latest game, 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 volumeShadow volume
Shadow volume is a technique used in 3D computer graphics to add shadows to a rendered scene. They were first proposed by Frank Crow in 1977 as the geometry describing the 3D shape of the region occluded from a light source...
s for shadowing while HPL 2 uses shadow mapping
Shadow mapping
Shadow mapping or projective shadowing is a process by which shadows are added to 3D computer graphics. This concept was introduced by Lance Williams in 1978, in a paper entitled "Casting curved shadows on curved surfaces"...
. The engine also boasts new effects such as Screen Space Ambient Occlusion
Screen Space Ambient Occlusion
Screen Space Ambient Occlusion is a rendering technique for efficiently approximating the well-known computer graphics ambient occlusion effect in real time...
and proper decals. This causes HPL 2 to have higher systems requirements than the previous HPL Engine.
The following games use this incarnation of HPL:
- Amnesia: The Dark DescentAmnesia: The Dark DescentAmnesia: The Dark Descent is a survival horror video game by Frictional Games, who previously developed the Penumbra series. Released for Windows, Mac OS X, and Linux platforms, the game features an unarmed protagonist exploring a dark and foreboding castle, while avoiding monsters and other...
HPL Engine 3
HPL 3 is currently in full development for Frictional's upcoming, untitled game. New major features mentioned are:- Global sunlight along with shadows, allowing fully lit outdoor scenes, a feature not implemented in previous versions.
- In-engine terrain generation and dynamic terrain LODLevel of detailIn computer graphics, accounting for level of detail involves decreasing the complexity of a 3D object representation as it moves away from the viewer or according other metrics such as object importance, eye-space speed or position....