Mass operator

The Mass operator allows you to control the mass of particles. The mass value of a particle will affect the way it behaves within the bind solver, as well as the PhysX solver.


Mass

  • Value: the initial absolute mass value assigned to particles.

  • Variation %: the per-particle percentage of variation to apply.
  • Clamp min: the minimum allowable mass value.

  • Clamp max: the maximum allowable mass value.

  • Relative to property: controls whether assigned mass values will be relative to a particle property.

  • Property: the property type which the mass value will be relative to.

  • *Threshold: the target threshold that particle property will be compared to, when assigning mass values.

  • Exponent: the exponent that particle property ratios will be raised to. Larger exponent values will increase the mass disparity between large and small property values.

  • Invert: controls whether the resulting property ratio will be inverted.

When “relative to property” is on, the following equation is used to calculate particle masses:

mass = pow(property value/(threshold), exponent)

  • Relative to bindings: controls whether masses will be affected by their distance to deactivated/kinematic particles in their binding network.

  • Particle bindings: regular particle bindings will be considered in the breadth-first traversal of the binding network.

  • PhysX bindings: PhysX bindings will be considered in the breadth-first traversal of the binding network.

  • Multiplier: the multiplier applied to masses, relative to their depth in the breadth-first search.

  • Exponent: the exponent applied to the depth-relative multiplier. The larger the exponent, the greater affect the multiplier will have on particles relative to their depth in the breadth-first search.

Interpolation

  • Normal interpolation: linearly interpolates the current value towards the target value.

  • Full interpolation on entry: linearly interpolates the particle's current value towards the target value, unless the particle's event age is 0 - then the particle's current value will be set to the target value.

  • Full interpolation at time of birth: linearly interpolates the particle's current value towards the target value, unless the particle's age is 0 - then the particle's current value will be set to the target value.

  • Curve interpolation (static): uses a curve to interpolate the particle's current value towards the value assigned to the particle when the particle first entered the event.

  • Curve interpolation (dynamic): uses a curve to interpolate the particle's current value towards the target value.

  • Duration: the number of frames over which the curve interpolation will be performed.

  • Value: the amount to linearly interpolate values each frame.

  • Variation %: the amount of variation to apply to the interpolation value.

PhysX Center of Mass

  • Set: controls whether to override the local center of mass offset value on PhysX particles.

  • X/Y/Z: the axis values for the center of mass offset, relative to the local particle transform.

Uniqueness

  • Seed: the seed value for all varied parameters.