Rigid Body World

Reference

Panel:Scene ‣ Rigid Body World

The Rigid Body World is a group of rigid body objects, which holds settings that apply to all rigid bodies in this simulation.

When you add rigid body physics on an object, primary there is created a group of objects with default "RigidBodyWorld" name. Rigid body objects automatically are added to this group when you add rigid body physics for them.

You can create several Rigid Body World groups and allocate the rigid body objects with the Groups panel in the Object tab.

Rigid body objects and constraints are only taken into account by the simulation if they are in the groups specified in Group field of the Rigid Body World panel in the Scene tab.

Settings

Rigid Body World
Enable/disable evaluation of the rigid body simulation based on the rigid body objects participating in the specified group of Rigid Body World.
Remove Rigid Body World
Remove rigid body simulation from the current scene.
Group
Containing rigid body objects participating in this simulation.
Constraints
Containing rigid body object constraints participating in the simulation.

Simulation quality and timing settings:

Speed
Can be used to speed up/slow down the simulation.
Split Impulse
Enable/disable reducing extra velocity that can build up when objects collide (lowers the simulation stability a little so use only when necessary). Limits the force with which objects are separated on collision, generally produces nicer results, but makes the simulation less stable (especially when stacking many objects).
Steps Per Second
Number of simulation steps made per second (higher values are more accurate but slower). This only influences the accuracy and not the speed of the simulation.
Solver Iterations
Amount of constraint solver iterations made per simulation step (higher values are more accurate but slower). Increasing this makes constraints and object stacking more stable.

Rigid Body Cache

The Rigid Body Cache panel specifies the frame range in which the simulation is active. Can be used to bake the simulation.

Start/End
First and last frame of the simulation.
Bake

Calculates the simulation and protects the cache. You need to be in Object Mode to bake.

Free Bake
Active after the baking of simulation. Clears the baked cache.
Calculate to Frame
Bake physics to current frame.
Current Cache to Bake
Bake from Cache.
Bake All Dynamics
Bake all physics.
Free All Bakes
Free all baked caches of all objects in the current scene.
Update All To Frame
Update cache to current frame.

If you have not saved the blend-file, the cache is created in memory, so save your file first or the cache may be lost.

Rigid Body Field Weights

As other physics dynamics systems, rigid body simulation are also influenced by external force effectors.