Spin operator

The Spin operator allows you to add spin motion to particles.

Mode

  • Set spin: assigns the specified value to the spin value of particles.

  • Add to spin: adds the specified value to the existing spin value of particles.

Units

  • Per frame: spin values are specified in degrees per frame.

  • Per second: spin values are specified in degrees per second.

Spin Rate

  • Spin magnitude type: the method used to derive the magnitude of the spin vector.

By Value: the magnitude will be set to an absolute value.

Inherit Previous: the magnitude will be set to the particle’s current spin magnitude.

Verlet: the magnitude will be set by measuring the change in rotation between the current frame and the previous frame.

  • Spin rate: the rate, in degrees per second, to spin particles.
Variation: the per-particle amount of variation to apply.

  • Relative to radius: the spin magnitude will be relative to a particle’s radius.

  • Radius: the threshold radius value.

  • Relative to velocity: the spin magnitude will be relative to a particle’s velocity.

  • Velocity: the threshold velocity value.

Relative to property

The relative property multiplier will adjust values based on the ratio between the value of a particle property and the specified threshold value.

  • Property type: the particle property to which the threshold value will be compared.

  • Threshold: the target value to which the selected property value of a particle will be compared.

  • Min multiplier: the minimum value of the resulting multiplier.

  • Max multiplier: the maximum value of the resulting multiplier.

  • Exponent: the exponent to which the ratio between the particle property and the selected property will be raised.

Spin Axis

  • Spin axis type: the method used to derive the axis of the spin vector.

Random 3D: the spin axis will be a random 3D vector.

World Space: the spin axis will be a user-defined vector in world-space coordinate.

Inherit Previous: the spin axis will be set to the particle’s current spin axis.

Travel direction: the spin axis will be aligned to the particle’s travel direction.

Towards/Away Object: the spin axis will be aligned towards/away the closest input object, depending on the sign of the magnitude.

Towards/Away Target: the spin axis will be aligned towards/away the target’s specified z-axis, depending on the sign of the magnitude.

  • Particle/world space: the source of the target’s z-axis coordinate. In particle space mode, the particle’s local z-axis will be used. In world space mode, the world z-axis will be used.

Verlet: the spin axis will be aligned to the change in rotation between the current frame and the previous frame.

  • X/Y/Z: the values of the user-defined spin axis vector.

  • Allow mirror: controls whether some particles will spin in the opposite direction.

  • Divergence: the degrees of random divergence to apply to the resulting axis vector.

Objects

  • Input object list: the list of scene objects to use for towards/away spinning.

Proximity Influence

  • Distance: particles within this distance will be fully affected.

  • Falloff: the effect on particles beyond the base distance, but within this falloff distance, will diminish according to the inverse-square law.

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.

Uniqueness

  • Seed: the seed value for all varied parameters.