PhysX World Helper

Set World Limits - Use this option to optimize the simulation performance. When on, the simulation is calculated accurately only inside the volume defined by the helper's icon. Outside the box the simulation is quite simplified; this typically means that forces are usually calculated but collision detection is not, because it's the most expensive part of simulation calculations.

With large particle count (thousands of particles), you can speed up calculation of the simulation significantly if this option is on; in some situations by an order of magnitude. The calculation speedup comes at the price of memory: If World Limits are known (when the option is on), the PhysX simulation engine makes a spatial analysis of this volume in relation to particle location.

Example:  PhysXWorldHelper_SetWorldLimits.zip