Spread operator

The Spread operator allows you to directly move particles in various directions, by adjusting their position instead of applying forces.

Coordinates

  • Particle/World space: controls which coordinate system the spread values will be calculated within.

  • Relative mode: when in particle space mode, the spread values will be transformed relative to the particle’s scale/radius/etc.

When relative modes are enabled, the spread vector will be multiplied by the selected particle property. So, for example, if you enable “relative to scale” and offset a particle 1 unit along the z-axis, and the particle has a scale of [5,10,20], the particle will be moved 20 units up along the direction of its transform’s z-axis in world space, even though in local particle space it will have only moved 1 unit along that axis.

Position Offsets

  • X/Y/Z: allows you to move particles along a world-aligned axis by a precise value.

Random Spread

  • X/Y/Z: the overall distance to move particles, in random directions.

  • ± X/Y/Z: controls the amount of variation to apply to the initial X/Y/Z distances.

Outward Spread

  • Outward spread %: moves particles outwards from the center of their bounds, evenly.
Clustering

  • Enable clustering: when enabled, particles will be grouped by matching cluster value before being spread outwards. Particles will be moved relative to the center of their cluster group.

  • Channel: the particle data channel to get cluster values from.

Velocity

  • Affect velocity direction: controls whether the direction between a particle’s old position and its new position will affect the direction of its velocity vector.

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.

Noise Spread

The noise settings allow you to offset the way in which particle positions are moved.

  • Noise mode: controls which noise algorithm will be used.

  • Noise texmap: the texmap that will be used by the noise texmap mode(s).

  • Noise preview: a preview image showing a 2D representation of the selected noise mode.

  • Strength: the strength of the noise (a multiplier on the default noise range of [-1, 1]).

  • Frequency: the speed at which the noise will evolve over time.

  • Scale: the scale multiplier for position values sent through the noise algorithm. Smaller values create larger noise patterns.

  • Roughness: controls the amount of extra detail applicable noise modes will generate.

  • Lacunarity: controls the scale of successive noise octaves for applicable noise modes.

  • Gain: controls the relative intensity of successive noise octaves for applicable noise modes.

  • Iterations/Octaves: controls the number of overlapping noise patterns that applicable noise modes will generate.

  • Phase: provides manual control over the evolution of the noise over time.

Uniqueness

  • Seed: the seed value for all varied parameters.

  • Seed by time: the seed value will be incremented with the current time in ticks.