decide what physics engine to use / #43

• Be cross-platform. At least Unix/Linux and Windows.
• Be open source.
• Be actively developed or maintained.
• Have good documentation or have a good community, so that we can get help easily.
• Be very accurate at high speeds (no explosions, no significant tunnelling).
• Support, at least, hinge/revolute (door axis), fixed (glue two objects) and prismatic (piston) constraint.
• Allow to use our own friction equations.

• Deformable bodies.
• Breakable bodies.
• Basic simulation of fluids (for aerodynamics).
• MacOS/PSX/XBox support.

Discarded (not suitable)

• Springhead
  • -Last updated 4 years ago.
• Solid Collision Detection Library
  • -Not a complete physics lib, just a collision detector. E.g it's used by Impulse Based.
• Fast
  • -Not a complete physics lib, just a collision detector.
• Tokamak:
  • -No support at all (forums inactive).
  • -Rarely updated.
  • +Breakable bodies.
• Dynamechs:
  • -No longer being developed (last change was 6 years ago).
  • +Basic hydrodynamic simulation.
  • +Runge-kutta 4 integrator available.
• Oxford Dynamics FastCar:
  • +Very fast.
  • -Only two suspension types.
  • -Not open source.
  • -No unix support.
• CHRONO::ENGINE:
  • -Not open source.
  • +Gears simulation.
• DynaMo:
  • +Many types of joints
  • +Several integrators, including runge-kutta 4 (accuracy).
  • -No community
  • -No longer being developed.
• Aero
  • -No mesh support.
  • -Not enough joint types supported.
  • -No longer being developed.
• Physsim (ask physsim people a few questions):
  • -No windows port available, and no plans. We did try to port physsim to windows, but it was deemed impossible in our time frames.
  • +Runge-kutta 4 integrator available.
  • +Native XML serialization.
  • -Small community, few docs.
  • -No generic trimesh support (only for closed shape meshes).
• OpenFDM
  • +Table driven aerodynamics (reads JSBSim files), good aero physics.
  • -Barely any manuals or documentation (just the code itself).
• JibLib
  • Sample fluid simulation (water+buoyancy, not built in).
  • -Little documentation.
  • +Actively developed.

In review

Accepted (fits our needs)

• PAL
  • +Allows to use ODE, Bullet, Tokamak, JigLib, IBDS, etc.
  • +Implements additional features not present in those engines by default.
  • -Lags a bit behind the latest features available in the underlying physics engines.
• ODE
  • +Support for many shapes.
  • +Very stable and mature.
  • +Big and active community.
  • +Good documentation.
  • -Fast but not very accurate integrators.
  • +Works in many platforms, including several videoconsoles.
• Bullet
  • +Experimental continous collision detection (small tunnelling effect).
  • +Parallelizable
  • +Works in many platforms, including several videoconsoles.
  • +Support for moving generic trimeshes, can be simulated with this: find out if we can use generic trimeshes in IBDS.
  • +Support for softbody simulation.
  • +Support for loading collada files.
• Impulse-based dynamic simulation (ask impulse based people a few questions)
  • +Runge-kutta/Taylor integrators available.
  • +Bullet/Solid collision detectors available.
  • +Support for particles and cloth.
  • -No box/cylinder/cone geoms.
  • +Concave trimesh support possible (find out if we can use generic trimeshes in IBDS), and planned for the near future.
  • +Heaps of joint types.
  • +Automatic computation of masses from geoms.
  • -Small community.
  • -Incomplete manual (but it'll be completed soon).
  • +Possible future implementation of deformable and breakable bodies.
  • +Planned support for computations distributed to several threads.
• (helper lib) OpenTissue (ask OpenTissue people a few things)
  • +Deformable bodies support.
  • +Good aero/particles simulation.
  • -Documentation a bit spread.
  • -Inactive community.