Rigid Bodies
Impact Constraint
Section titled “Impact Constraint”Glues neighbouring pieces together until enough force breaks the bond.
Inputs: Group: Pieces to act on. Unlinked means every piece.; Group B: The second group of pieces. Unlinked means every piece outside
Outputs: Constraints: Glue bonds between pieces. Accepts Impact Constraint nodes.
| Setting | What it does | Default |
|---|---|---|
| Constraint Type | How the bonds behave under load: snap, bend permanently, or spring back | GLUE |
| Breaking Force | Tensile/shear Lagrange multiplier threshold required to break glue bonds | 45 |
| Shear Strength Ratio | Shear strength as a fraction of tensile strength. Lower snaps more easily under sideways load (concrete ~0.6, steel ~1.4, glass ~0.3) | 0.6 |
| Stiffness | How stiff the bonds between adjacent pieces are. Higher holds the structure more rigidly | 1e+06 |
| Yield Strain | Strain threshold beyond which bonds undergo permanent plastic deformation | 0.08 |
| Creep Rate | Rate of permanent plastic deformation per second | 0.4 |
| Sound Speed (m/s) | Speed of sound through material (m/s). 0 = instant shockwave, >0 simulates finite acoustic stress waves | 0 |
| Wave Impact Speed | Approach speed threshold that triggers stress wave emission through the bond graph | 5 |
| Fatigue Rate (1/s) | Sub-critical cyclic load damage accumulation rate (0 = no fatigue) | 0 |
| Fatigue Limit | Endurance limit as a fraction of breaking threshold: loads below this cause no damage | 0.5 |
| Fatigue Exponent (n) | Basquin exponent controlling how steeply damage scales with cyclic stress | 4 |
| Bonds | Which bonds of the Group these settings apply to | INSIDE |
Impact Rebar
Section titled “Impact Rebar”Adds steel reinforcement along a curve that holds broken concrete pieces together.
Inputs: Group: Pieces to act on. Unlinked means every piece.
Outputs: Rebar: Reinforcement that holds pieces together. Accepts Impact Rebar
| Setting | What it does | Default |
|---|---|---|
| Curve / Mesh | 3D Curve or edge-mesh object defining the reinforcement path running through the shards | |
| Rebar Stiffness | How stiff the rebar ties are. Higher keeps the rebar from stretching under load | 200000 |
| Yield Strain | Strain threshold where rebar undergoes permanent ductile elongation | 0.1 |
| Max Stretch | Ultimate tensile elongation before rebar tethers snap | 0.5 |
| Creep Rate | Ductile rebar plastic flow rate under persistent tension | 0.3 |
| Rebar Links | Number of neighboring Voronoi chunks anchored to each rebar segment | 2 |
Impact Debris
Section titled “Impact Debris”Spawns chips, dust and sparks when bonds break or pieces hit something.
Inputs: Group: Pieces to act on. Unlinked means every piece.
Outputs: Debris: Chips and dust spawned when pieces break. Accepts Impact Debris
| Setting | What it does | Default |
|---|---|---|
| Splinters Per Snap | Number of secondary GPU rubble particles spawned per broken glue bond | 4 |
| Debris Style | Material the debris looks like and how it is shaded | CONCRETE |
| Impact Debris | Eject secondary chips/dust when high-speed shards strike colliders or the ground | True |
| Impact Speed Thresh (m/s) | Minimum approach normal speed to trigger secondary chip ejection | 3 |
| Chips Per Impact | Number of secondary chips/dust particles ejected per high-speed impact | 4 |
| Air Drag | Aerodynamic drag resistance for airborne particulates and dust | 1.5 |
| Wake Suction | Slipstream drag coupling pulling dust in the wake of falling chunks | 2.5 |
Impact Joint
Section titled “Impact Joint”Connects two pieces, or a piece and the world, as a hinge, slider, ball, spring or weld.
Outputs: Joint: A joint between pieces. Connect it to the Impact Solver’s Joint
| Setting | What it does | Default |
|---|---|---|
| Type | How the two bodies are connected and which motions the joint allows | HINGE |
| Shard A | Fracture shard driven by the joint (must belong to the fractured source) | |
| Shard B | Second shard. Empty: Shard A is jointed to the fixed world | |
| Pivot | Object (usually an Empty) whose location is the joint point and whose orientation gives the axis. Empty: the point between the two shards, or Shard A’s centre for a world joint | |
| Axis | Hinge / slider axis: the pivot object’s local axis, or the world axis without a pivot | Z |
| Swing | Half-angle of the cone the joint axis may swing within | 0.785398 |
| Twist | How far (each way) the shard may turn about the joint axis | 0.523599 |
| Limit | Restrict the hinge angle / slider travel | False |
| Lower | Smallest hinge angle allowed, turning the negative way (needs Limit) | -1.5708 |
| Upper | Largest hinge angle allowed, turning the positive way (needs Limit) | 1.5708 |
| Lower | Farthest the slider may move along the negative axis (needs Limit) | -0.5 |
| Upper | Farthest the slider may move along the positive axis (needs Limit) | 0.5 |
| Motor | Drive the hinge / slider at a target speed | False |
| Speed | Target turning speed per second (hinge) | 3.14159 |
| Speed (m/s) | Target sliding speed (slider) | 0.5 |
| Strength | Most force / torque the motor can apply, in multiples of Shard A’s own weight (torque: weight times its radius). 1 just holds the shard up against gravity | 5 |
| Frequency (Hz) | Oscillations per second of Shard A on the spring | 2 |
| Damping Ratio | 0 = rings forever, 1 = settles without overshoot | 0 |
| Softness | Lets ball / hinge / slider / fixed attachments give a little (0 = rigid) | 0 |
| Breakable | The joint snaps when the load passes Break Strength. Off: it never breaks | False |
| Break Strength | Force at which the joint snaps, in multiples of Shard A’s weight (torques: weight times radius) | 10 |
Impact Group
Section titled “Impact Group”Selects a set of pieces by region, height, attribute, collection or at random.
Inputs: Group: Pieces to act on. Unlinked means every piece.
Outputs: Group: Pieces to act on. Unlinked means every piece.
| Setting | What it does | Default |
|---|---|---|
| Select | How the pieces are chosen: all, by source, collection, volume, height, custom property or at random | ALL |
| Impact Source | Name of the Impact Source node | |
| Collection | Collection whose objects (children included) are the selected pieces | |
| Object | Pieces inside this object (it is read at the first frame) | |
| Shape | Which part of the object counts as inside | BOX |
| From | Bottom of the band along Z, as a fraction of the selection’s height (0 = bottom) | 0 |
| To | Top of the band along Z, as a fraction of the selection’s height (1 = top) | 0.5 |
| Property | Name of the custom property to look for on the piece objects | blux_group |
| Test | How the property is tested: it equals a text, it exists, or it lies in a number range | EQUALS |
| Value | Text the property must equal (numbers are compared as text) | |
| Min | Lowest value of the property that is still selected | 0 |
| Max | Highest value of the property that is still selected | 1 |
| Fraction | Share of the pieces to select: 0.5 selects about half | 0.5 |
| Seed | Picks a different random set of pieces. The same seed always picks the same ones | 0 |
| Invert | Select the pieces the test does not | False |
| Grow | Also select the pieces up to this many bonds away | 0 |
Impact Group Combine
Section titled “Impact Group Combine”Joins two groups of pieces into one: union, intersection or difference.
Inputs: Group A: The first group of pieces.; Group B: The second group of pieces. Unlinked means every piece outside
Outputs: Group: Pieces to act on. Unlinked means every piece.
| Setting | What it does | Default |
|---|---|---|
| Operation | How the two groups merge: pieces in either, in both, or in A only | UNION |
Impact Activation
Section titled “Impact Activation”Decides when a group of pieces wakes up: on impact, on proximity or on a trigger.
Inputs: Group: Pieces to act on. Unlinked means every piece.
Outputs: Activation: When groups of pieces wake up. Accepts Impact Activation nodes.
| Setting | What it does | Default |
|---|---|---|
| Mode | How these pieces start: simulated, asleep, held until triggered, or fixed in place | START_DEACTIVATED |
| Pin in Place | Anchor these pieces: they never move until a Trigger unpins them | False |
| Trigger Radius (m) | Distance at which a collider releases the pieces (0 = contact) | 0 |
| Wake Lookahead (m) | Releases held pieces just before a moving collider arrives, looking this far ahead along its path. 0 = off | 0.5 |
| Impact Energy Transfer | Strength of the kick a collider gives these pieces on impact. 1 = a normal bounce, 0 = no kick | 1 |
| Proximity Delay (s) | Seconds a held piece waits, once moving pieces are near it, before it is released | 0.2 |
| Proximity Radius (m) | How close moving pieces must come to a held piece to start its release | 0.4 |
| Speed Threshold (m/s) | Slowest speed at which a moving piece releases its neighbours | 0.1 |
Impact Trigger
Section titled “Impact Trigger”A volume or a frame range that wakes, releases or weakens the pieces it touches.
Inputs: Group: Pieces to act on. Unlinked means every piece.
Outputs: Trigger: A trigger volume or frame range. Connect it to the Impact Solve
| Setting | What it does | Default |
|---|---|---|
| Where | Where the trigger acts: on every piece, or on the pieces inside the object’s box or sphere | BOX |
| Object | The volume; animate it to sweep through the pieces | |
| Start | First frame on which the trigger acts | 1 |
| End | Stop acting after the End frame | False |
| End | Last frame on which the trigger acts (needs the End toggle) | 250 |
| Activate | Release held pieces (deactivated / trigger modes) | True |
| Wake | Wake sleeping pieces | False |
| Unpin | Release anchored (pinned, static) pieces | False |
| Break Bonds | Snap every bond of the pieces inside | False |
| Weaken Bonds | Multiply the strength of their bonds by the factor (once) | False |
| Factor | Share of the bond strength that is left: 0.5 halves it, 0 removes it, 1 changes nothing | 0.5 |
| Freeze | Stop the pieces and hold them in place | False |
| Add Velocity | Give each piece a kick, once | False |
| Velocity | Velocity added to each piece, in world space (m/s) | (0, 0, 0) |
| Outward (m/s) | Speed away from the volume’s centre (negative: towards it) | 0 |
| Once per Piece | Act on a piece (or bond) the first time only; off: every substep it is inside | True |