The fracture tool

Fracture Selected Mesh (in the Solver panel when Impact is active) slices the active mesh into Voronoi chunks with interior fracture textures and breakable XPBD glue bonds. It opens a dialog first.

The mesh must be a Mesh object. Otherwise BLUX reports Please select a Mesh object to fracture.

Cutting time grows with the piece count, because each piece is cut out of the whole mesh. A few hundred is quick. A thousand takes minutes.

Material preset

The preset sets the chunk count, bond strength, crack gap and the roughness of the cut faces. Custom uses your own values.

Preset	Character
Concrete / Masonry	Standard concrete or masonry structure. The default.
Natural Stone	Dense rock with coarse, jagged fracture faces.
Tempered Glass	Brittle fracture, high shard count, low bond strength.
Wood / Timber	High strength, fibrous yielding.
Brick / Mortar	Segmented mortar bonds with high friction.
Ductile Metal	High plastic crumpling and deformation.

Core options

Setting	Default	What it does
Chunk Count	32	Number of Voronoi pieces (4 to 1,024).
Random Seed	42	Seed for the cell distribution.
Bond Strength	45	Force threshold to break glue bonds between chunks.
Crack Gap Margin	0	Spacing between chunks. 0 is flush.
Fracture Roughness	by preset	Height of the bumps on the cut faces, as a fraction of the mean chunk size. 0 is flat.
Fracture Feature Size	by preset	Width of those bumps.

Bond strength is weighted by the contact area between two pieces, so larger shared faces hold harder.

Crack pattern

Pattern	Seeds go…	Good for
Even	spread evenly through the volume.	General demolition.
Impact Point	crowded around a point of impact: small pieces there, large ones away from it.	A wall hit by a ball.
Radial (Glass Crack)	on rings and spokes around the impact point, cut through the whole thickness of a sheet.	A struck pane of glass.
Wood Fibres	stretched along an axis, so pieces are long fibres.	Splintering timber.

Pattern option	Applies to	What it does
Impact (object)	Impact Point, Radial	An object (usually an Empty) marking where it hits. Empty: the centre of the mesh.
Impact Spread	Impact Point	Size of the crowded region, as a fraction of the mesh size (default 0.25).
Impact Share	Impact Point	Share of the pieces placed around the impact (default 0.7). The rest spread through the volume.
Sheet Normal	Radial	The axis across the thickness of the sheet. Thinnest picks it automatically.
Fibre Direction	Wood Fibres	The axis the fibres run along. Longest picks it automatically.
Fibre Length	Wood Fibres	How many times longer than wide the fibres are (default 4).

Hierarchical clustered impact

Macro Clustering groups the pieces into macro clusters with fortified bonds inside each cluster.

Setting	Default	What it does
Cluster Count	4	Number of macro blocks.
Cluster Glue Strength	5	Multiplier on intra-cluster bond strength relative to inter-cluster bonds.

A structure then breaks into large blocks first, instead of crumbling into dust.

Rebar

Curve (a curve or edge-mesh object) runs through the mesh as reinforcement. The shards it passes through stay tethered along it after the brittle glue snaps.
Auto Core Rebar adds a straight bar through the middle along the mesh’s longest axis, for columns and beams.

See Bonds and rebar.

After fracturing

Option	Default	What it does
Interior Fracture Material	on	Assigns a rough concrete or stone material to the cracked inner faces.
Setup XPBD Rigid Node Graph	on	Sets up an Impact graph connected to the fractured mesh.
Hide Original Mesh	on	Hides the unfractured source mesh in the viewport and renders.

The original mesh is kept, just hidden.

Mesh tips

If you see Fracture failed, the message after it names the cause.
If an object named in Impact or Rebar is not found, BLUX warns and carries on with the centre or without rebar.

The Material Preset menu in the Solver panel (Concrete, Glass, Wood, Brick, Metal) applies a calibrated rigid-body preset to the solver settings of an already fractured structure.