The Spread operator allows you to directly move particles in various directions, by adjusting their position instead of applying forces.
Particle/World space: controls which coordinate system the spread values will be calculated within.
Relative to particle scale: when in particle space mode, the spread values will be transformed relative to the particle’s scale.
When “relative to particle scale” is enabled, the scale of each axis of the particle’s transform will act as a multiplier on the resulting spread vector. So if you 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.
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.
The noise settings allow you to offset the way in which particle positions are moved.
Strength: the strength of the noise.
Frequency: the frequency of the noise. Increasing this value will evolve the noise pattern over time.
Scale: the scale of the noise.
Roughness: the roughness of the noise.
Iterations: the number of iterations to use to calculate the noise.