System Physics

Global physics engine selection, timestep settings, and gravity for the scene.

Default Engines

PMX Default sets the physics engine used for PMX models with built-in rigidbodies and joints (hair, skirts, accessories). Choose PhysX for Unity’s joint-based physics, XPBD for a particle-based simulation, or Off to disable and free those bones for the XPS custom physics tools.

Custom Physics Default sets the engine for the XPS tools (Hair Physics, Cloth Physics, Softbody, etc.). XPBD is more stable for cloth; PhysX may be faster on some hardware.

PhysX Settings

Gravity sets the downward force applied to all rigidbodies. Set it to zero for a zero-gravity stage. Disable Collision prevents XPS particle systems from colliding with each other, which can reduce jitter when multiple soft bodies interact.

XPBD Settings

Holds simulation parameters for the XPBD engine — see the XPBD Settings sub-data for details.

Time

Time Scale slows or accelerates the physics simulation independently of animation playback speed. Lower values make particles and soft bodies move in slow motion. Physics FPS locks the simulation to a fixed timestep: lower values reduce CPU load, higher values improve stability at the cost of performance. Flexible lets the simulation run at the render framerate.

Sub-Components

XPBD Settings

Holds XPBD solver settings: substeps, iterations, collision interval, self-collision, body collision, ground friction, expand radius, and parallel solving.