PhysX Collision operator

The PhysX Collision operator allows you to add colliders to a PhysX simulation, and set test conditions for colliding particles.

Only mesh colliders are supported. Spacewarp colliders are not supported.

Colliders

  • Input collider objects: the geometry colliders to add to a PhysX simulation.
Hull Type
  • Hull Type: allows you to choose the collider collision hull.

Sphere: a perfectly spherical hull.

Box: a bounding box hull.

Convex Hull: a convex hull encapsulating collider mesh vertices.

Mesh: the collider’s mesh will be used as the hull.

  • Display Hull: displays the collider hull in the viewport.
Shape Dimensions
  • Fit Bounding Box: controls whether spherical hulls will encapsulate the bounding box of the collider’s mesh.
Bounce and Friction

  • Restitution: the restitution coefficient for the collider. Similar to “bounce”.

  • Static/Dynamic friction: friction coefficients for the collider.

Collider Simulation Groups
  • Simulation groups: controls which particle simulation groups will be used to filter collisions.

Test For:

  • Inter-particle collisions: collisions between particles may satisfy the test condition.

  • Geometry collisions: collisions between particles and geometry colliders may satisfy the test condition.

  • Ground collider collisions: collisions between particles and the default PhysX ground plane may satisfy the test condition.

Extra Test Conditions

If any extra conditions are enabled, they will factor into whether a particle satisfies the test condition.

  • Test operator: the logical operator controlling how extra test conditions are considered.

AND: all enabled extra conditions must be satisfied in order for a colliding particle to satisfy the test.

OR: any enabled extra conditions must be satisfied in order for a colliding particle to satisfy the test.

Collision Count

A particle must collide a certain number of times before it will satisfy this condition.

  • Min: the minimum number of collisions.
Minimum Impulse

The minimum impulse of a particle’s collision must be above a certain value before it will satisfy this condition.

  • Min: the minimum impulse value.
Maximum Impulse

The maximum impulse of a particle’s collision must be below a certain value before it will satisfy this condition.

  • Max: the maximum impulse value.
Minimum Penetration

The penetration value of a particle’s collision must be above a certain value before it will satisfy this condition.

  • Min: the minimum penetration value.
Mass coefficient

When greater than one, the ratio between the mass of a particle and its collider must be greater than a specified value in order to satisfy this condition. When less than one, the opposite is true. When equal to one, a particle and its collider must have the same mass in order to satisfy this condition.

  • Value: the test value.
Volume coefficient

When greater than one, the ratio between the volume of a particle and its colliding particle must be greater than a specified value in order to satisfy this condition. When less than one, the opposite is true. When equal to one, a particle and its colliding particle must have the same mass in order to satisfy this condition.

  • Value: the test value.
Event Age

A particle’s event age must be within a defined range before it will satisfy this condition.

  • Min/Max: the event age range.
Frame

The current simulation frame must be within a defined range before particles will satisfy this condition.

  • Min/Max: the frame range.
Collider type

Only particles with a certain PhysX collider rigidbody type will satisfy this condition.

  • Dynamic/Kinematic: the PhysX collider rigidbody type.
Simulation Groups

Only particles matching a certain set of simulation groups will satisfy this condition.

  • Simulation groups: the simulation groups.