The Birth Voxels operator allows you to birth particles inside the volume or surface of scene objects, at uniform spatial intervals.
Start/End: controls the time range in which to birth new particles.
Enable every nth: when enabled, particles will be birthed at regular frame intervals, instead of at every frame.
Nth value: the interval value at which to birth particles.
Mode: controls where particles will be birthed, relative to the surface or volume of a particular input object.
Sample type: controls the quality of samples used to determine surface proximity, when birthing particles in “Surface” mode.
Voxel size X/Y/Z: the size of individual voxels, in which particles will be birthed.
Accuracy: controls the accuracy of the raycaster used to compute information about whether a particle is inside or outside of an object’s volume.
If an input object’s surface is not closed, or is self-intersecting, increasing the accuracy value can improve results and reduce artifacts.
Scale type: controls which size value particle will derive their scale from.
Mult: a global scale multiplier applied to all particles.
Grains: choosing this preset will apply a progressive offset to particles, such that their positions in space will form a tightly-knit overlapping grid.
Grid: choosing this preset will remove all offsets from particles, such that their positions in space will form a uniform, aligned grid.