Introduction

The Physics Abstraction Layer (PAL) provides a unified interface to a number of different physics engines. This enables the use of multiple physics engines within one application. It is not just a simple physics wrapper, but provides an extensible plug-in architecture for the physics system, as well as extended functionality for common simulation components.

PAL provides a number of benefits to game and simulation developers. First of all PAL is very easy to use, so you can easily integrate physics into your application. Secondly, it does not restrict you to one particular physics engine. This gives you more flexibility, allowing you to easily upgrade your physics system if you decide to pursue a commercial engine, select different engines for alternative platforms, or swap to another engine if the physics engine developers stop development and support for their engine. This flexibility allows you to choose the engine that gives you the best performance for your application. Finally, PAL has an extensive set of common features such as simulating different devices or loading physics configurations from XML, COLLADA and Scythe files.

PAL makes physics development FLEXIBLE, FAST and EASY.

The source code for PAL is available via CVS access to sourceforge.
You can also download a zip of the latest CVS source code.

The windows install instructions provide a simple step by step process for configuring PAL for your system.

Precompiled binary packages are no longer distributed. Please use the premake configuration system that is distributed with PAL.

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Features

PAL supports a large number of physics engines. It provides a unique interface for:

Physics Engines
- Ageia PhysX (a.k.a Novodex)
- Box2D (experimental)
- Bullet
- ~~Dynamechs~~(deprecated)
- IBDS (experimental)
- JigLib
- ~~Meqon~~(deprecated)
- Newton
- ODE
- OpenTissue (experimental)
- Simple Physics Engine (experimental)
- Tokamak
- TrueAxis
File Formats
- Collada
- Scythe
- ~~PAL XML~~(deprecated)
Bodies
- Box
- Capsule
- Compound
- Convex
- Sphere
Geometries
- Box
- Capsule
- Convex Mesh
- Concave Mesh (Terrain)
- Height field (Terrain)
- Plane (Terrain)
- Sphere
Links
- Spherical (Ball and Socket) Link
- Revolute (Hinge) Link
- Prismatic (Slider) Link
- Generic 6DOF Link
Sensors
- Contact
- Compass (Angular position)
- GPS (Global Positioning System - Position)
- Gyroscope (Angular velocity)
- Inclinometer (Angular position)
- PSD (Position Sensitive Device - Ray casting)
- Velocimeter (Linear velocity)
- Transponder (Distance between two objects)
Actuators
- Force actuator (Generic)
- DC Motor
- Servo Motor
- Hydrofoil
- Propeller
- Spring
Fluids
- Particle Fluids (SPH)
- Buoyancy Force
- Drag Force
Vehicles

PAL also features an extensive testing and benchmark suit for evaluating and visualizing dynamic simulation systems.

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News

13/01/08

A very experimental version of Box2D support is now in the CVS, the installer has been updated to let you save configurations, and PAL now has a basic static compound body. Also added the tutorial integrating Irrlicht with PAL.

PAL is now slowly migrating to SVN, and the CVS repository will eventually be removed. Danny Chapman has joined the PAL project, and will provide improved support for the Jiglib engine among other things.

04/01/08

The installation system has been updated to provide linux support for ODE and Novodex. (Thanks to Volker Darius for the linux support contribution). The windows installer has been updated to enable support for experimental PAL physics engines. OpenTissue implementation has been updated to v0.992.

30/12/07

An experimental version of fluid support and SPE support is now in the CVS.

28/12/07

The first version of the PAL redesign has been comitted to CVS. Major changes are a new build system, and an internal rewrite to simplify support for new geometries and physics engines. As a result, the "Cylinder" has also been renamed to "Capsule".

Currently only the Bullet physics engine supports the new design, with Novodex also providing partial support. Experimental support for IBDS has also been included in the CVS.

15/12/07

PAL is currently undergoing a rewrite to enable better support for more physics engine designs and to simplify support for different operating systems and compilers. As a result, the CVS solution and project files are out of date. We hope to have the new build system available soon. (Thanks to Alexander Steiger for the bug report)

05/12/07

A paper evaluating the PAL engines was published, available from the ACM: Evaluation of real-time physics simulation systems. The online physics engine benchmark contains more up to date results.

18/11/07

PAL online physics engine benchmark has been updated. You can now view the stack test penetration error, friction test results, and stress test results.

15/11/07

PAL Scythe loader has been released. The Scythe loader is based on code from the Scythe project and contributions by Pål Ruud. Many thanks to Pål Ruud for his effort.

14/11/07

Martin Sawtell contributed a logo for the PAL project.

03/11/07

PAL benchmark has been updated for penetration error checking in stacked objects

01/11/07

3d-test PAL interview was published.

24/10/07

PAL COLLADA loader has been released. The COLLADA loader is based on code from John Ratcliff. Many thanks to John Ratcliff for making the code to his lightweight COLLADA physics loader publicly available.

23/10/07

PAL updated to a new force system, and version requesting is supported. PAL MSVC8 package updated to include framework and tinyXML files (Thanks Alex McLeod).

17/10/07

PAL Benchmark intractive graphs are now available online

14/10/07

PAL Benchmark is now in CVS

03/09/07

PAL Website is online

25/08/07

Started a website for PAL.

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Contact

The offical PAL website is at: pal.sourceforge.net. The PAL project page is also available from sourceforge.

You can post general questions to the PAL sourceforge forum, or you can contact Adrian Boeing directly from the Adrian Boeing web site.