Bounds Fracture operator

The Bounds Fracture operator allows you to slice particle meshes across the longest axis of their oriented bounding box.

This operator is ideal for slicing long, thin particles up along their longest local bounding box axis.

Bounds Fracture Rollout

Bounds Fracture

  • Length ratio threshold: the minimum ratio between the length of the longest local bounding box axis, and the second longest bounding box axis, in order for a particle to qualify for bounds slicing.

A long, thin particle is a particle with a local bounding box axis that is considerably longer than its other two bounding box axes. For example, a particle with local bounding box dimensions of [10, 1, 0.5] will be long and thin because its bounding box X-axis is at least 10 times longer than both its Y and Z-axes (this ratio is what is measured by the length ratio threshold). In that example, if you set the “length ratio threshold” setting to 5, the particle will qualify for slicing because 10 is greater than 5. However, if you set the length ratio threshold to 15, the particle will not qualify for slicing because 10 is less than 15.

Slice Count
  • Absolute: the number of slices for qualifying particles will be absolute (the same).

  • Relative: the number of slices for qualifying particles will be relative to the ratio between the length of their longest and second longest local bounding box axes.

When “relative” slice count mode is enabled, the number of slices set by the “count” setting will be multiplied by the length ratio, described above.

  • Count: the base number of slices, per qualifying particle.

  • Variation %: the per-particle percentage of variation to apply.

  • Slice plane divergence: the maximum angle that any given slice plane normal will diverge from the direction of the longest bounding box axis.

  • Slice offset variation %: the amount of offset variation to apply to the slice plane’s position along the longest bounding box axis, relative to the distance between each slice.


  • Seed: the seed value for all varied parameters.

Fracture Meshes

  • Center pivots: controls whether the pivots of resulting fracture particles will be centered on their mesh.