CARNAGE GRAINS / DOCUMENTATION

Activation

Control when grains enter the simulation, from a single release frame to spreading activation effects.

Grains Active

ActiveDefault: On: Allow grains to activate and participate in the simulation. When disabled, grains remain inactive and can follow Point Deform.

This switch is the master gate for activation. It is displayed as Grains Active or Grains Inactive and can be keyframed. Keep it on while using spatial activation methods so those methods can release grains. Configure the activation setup before starting.

Progressive Activation

Progressive ActivationDefault: Off: Release grains at different times using a noise pattern, spread over the specified number of frames.
Spread (frames)Default: 30.0: Time range over which the noise pattern distributes grain activation, starting when activation begins.
Noise ScaleDefault: 2.0: Size of the noise features controlling activation order. Higher values produce larger regions with similar activation times.
Noise OffsetDefault: 0.0, 0.0, 0.0: Offset of the noise pattern used to assign activation times.
InvertDefault: Off: Reverse the noise values used to assign activation times, swapping earlier and later regions.

Empty Activation

Empty ActivationDefault: Off: Activate grains within the spherical regions defined by the listed empties. Move or scale the empties to control their reach.

Use the plus/minus controls to manage the empty list. Each row can be enabled separately. Assign an Empty to each entry; its world X scale determines its spherical activation radius. Animate position or scale to move or grow its reach.

EnabledDefault: On: Use this empty to activate grains.
Empty: Empty defining a spherical activation region. Its world X scale controls the region's radius.

Radial FalloffDefault: On: Reduce activation progress toward the edge of each empty's region, so grains nearer the center activate sooner.
Falloff CurveDefault: Smoothstep: Shape of the decrease in activation rate from the center of an empty to its edge.
Linear: Decrease activation rate evenly from the center to the edge.
Smoothstep: Decrease activation rate with a smooth transition at the center and edge.
Power: Use Power to control how strongly activation is concentrated near the center.
PowerDefault: 2.0: Concentration of activation toward the center. Higher values slow activation more strongly near the edge.
JitterDefault: 0.3: Randomly varies each grain's activation rate within empty regions, breaking up synchronized releases.
Activation RampDefault: 5: Time in frames required to activate a grain while it remains within an empty's influence at full strength. Falloff and Jitter can change the release time. A value of 0 releases grains immediately.

Curve appears when Radial Falloff is enabled; Power appears for the Power curve. An Activation Ramp of zero releases immediately.

Object Activation

Object ActivationDefault: Off

Activate grains reached by the selected mesh or extruded/beveled curve.

Activation Object

Mesh or curve with generated faces whose volume or surface activates grains. Inside Volume requires a closed surface.

ModeDefault: Inside Volume

Whether the object activates grains through its interior or near its surface.

Inside Volume: Activate grains reached by the object's interior. Use a closed surface with consistently oriented normals; cap beveled curves.
Near Surface: Activate grains within Surface Distance of the object's surface, on either side.

Show MaskDefault: Off

Show the object's current reach: white inside the activation region, black outside. Use Material Preview or Rendered shading.

Tip: Turn off Grains Active to preview the animated mask while keeping the grains still.

Surface DistanceDefault: 0.1

Distance from the activation object's surface within which grains activate in Near Surface mode.

The object must produce faces. A bare curve without bevel or extrusion has no surface to test. For Inside Volume, close the mesh or cap the curve. Object activation is not itself a collision surface—add the object to Colliders if it must also collide.

Start Asleep

Start AsleepDefault: Off: Start grains in a frozen state so they remain at rest until woken.
Wake RadiusDefault: 2.5: Distance around active grains within which frozen grains can wake, measured in grain diameters.

This is the initial sleep state, separate from Point Deform’s source-following behavior. Use Freeze At Rest to freeze grains after they settle.

An explicit activation from an Empty, Object, Mask or Infection also wakes affected grains. Wake Radius controls waking through nearby active grains.

Infection

InfectionDefault: Off: Activate grains through a spreading region, contact with infected grains, or both.

Use Add Emitter to add a source object; the row’s checkbox controls whether it seeds infection. Region grows across gaps, Contagion spreads through grain contact, and Both combines them.

EnabledDefault: On: Use this emitter to seed infection.
Emitter: Object whose origin seeds the infection spread.

Spread ModeDefault: Region: How infection spreads from emitters and between grains.
Region: Activate grains inside expanding regions around emitters, including across gaps in the material.
Contagion: Seed infection near emitters, then spread it between grains within the contact distance.
Both: Combine expanding emitter regions with grain-to-grain spread through contact.
SpeedDefault: 1.0: Rate at which each emitter's infection region expands, in scene units per second. Supports keyframes; zero pauses growth. Re-simulate after changing keys.
Start FrameDefault: 1: Frame on which infection begins spreading from the emitters.
Contagion RateDefault: 8.0: Rate at which infection passes between nearby grains. Higher values shorten the delay. Once a grain receives infection, the delay can finish after the source grain moves away.
Contact SlopDefault: 0.0: Allowed gap between grain surfaces for contact infection. A small automatic allowance covers packing gaps; larger values extend the reach. This setting does not change the connections used by Activate Detached Grains.
Activate Detached GrainsDefault: Off: Once infection reaches a shape, release pieces that lose their connection to its largest piece. Connections use nearby grains and intact glue bonds; initially separate shapes are tracked independently. Adds memory use and a connection check each active frame.
Release AggressivenessDefault: 0.0: How strongly already-active grains are excluded from the connection check. At 0, active grains can keep a piece connected; at 1, only connections between inactive grains count. Higher values usually release pieces sooner without weakening physical glue bonds.
Fallen Grains SpreadDefault: On: Allow infected grains to start new transmissions regardless of how far they have moved from their infection position. Previously received infection can still finish its delay. When off, Contagious Travel limits new transmissions.
Contagious TravelDefault: 4.0: Limits how far an infected grain can move from where it became infected and still pass infection to nearby grains. At 4.0, it can spread infection while within four grain diameters of that position. This helps prevent falling grains from carrying infection to other parts of the scene. Applies when Fallen Grains Spread is off.
Output ColorDefault: Off: Store colors identifying clean, infected and detached grains for visualization and shading. View them in Material Preview or Rendered shading.
Clean ColorDefault: 0.8, 0.8, 0.8, 1.0: Color assigned to grains that have not been infected.
Infected ColorDefault: 0.6, 0.05, 0.05, 1.0: Color assigned to infected grains and pieces released by Activate Detached Grains.
Boundary NoiseDefault: Off: Make infection spread unevenly. Region varies the expanding boundary; Contagion varies the delay between nearby grains; Both combines these effects. Contact spread still requires nearby grains.
Noise AmountDefault: 3.0: Strength of the irregular spread. In Region mode, offsets the boundary in grain diameters. In Contagion mode, varies the transmission delay; higher values create larger differences in local spread speed.
Noise Feature SizeDefault: 8.0: Size of the noise features, measured in grain diameters. Higher values create broader regions with similar boundary offsets or transmission delays.
Noise Crawl SpeedDefault: 1.0: Rate at which the noise pattern changes over time. Zero holds the pattern still.

Speed controls region growth in Region/Both. Boundary Noise works in all spread modes. Contagion controls appear in Contagion/Both; Contagious Travel appears when Fallen Grains Spread is off. Release Aggressiveness appears when Activate Detached Grains is on.

Keyframing Speed to zero pauses region growth; it does not undo infection. Noise crawling, contagion, and moving emitters can still change the result. See Animating infection.

Keep Grains Active on to allow infection to release grains. Infection waits for Start Frame and an enabled emitter; while waiting, it holds grains that have not been released by another activation method.

Detached pieces stay active and use the infection color, but spread infection only when they are actually infected. For a black-and-white shader input, see Transfer Infection Mask.

Mask Activation

Mask ActivationDefault: Off: Activate grains whose mask value exceeds Threshold. The mask is sampled each frame, and activated grains remain active.

Activates grains with a mask value strictly above Threshold. It is sampled every frame and latches on: lowering the mask afterwards does not put released grains back into the inactive state.

ThresholdDefault: 0.5

Mask value a grain must exceed to activate. Lower values allow more of the mask to activate grains.

SourceDefault: Noise

Method used to generate the mask values.

Noise: Uses procedural 3D noise sampled at grain positions to generate the mask.
Weight Paint: Uses weights from a vertex group on the fill mesh to define the mask. Each grain receives the weight of the nearest mesh vertex.
Texture: Uses an image or procedural Blender texture to define the mask, mapped using grain positions or the fill mesh's UV coordinates.

Texture

Blender texture used to supply mask values.

CoordinatesDefault: Object

Coordinate system used to sample the texture.

Object: Sample the texture using grain positions in the Mapping Object's local coordinates, or world coordinates when no object is assigned.
UV: Find the nearest point on the fill mesh’s surface and interpolate its face-corner UV coordinates to sample the texture. This preserves UV seams.

UV MapDefault: Empty

UV map on the fill mesh used to sample the texture. Leave empty to use the active UV map.

Mapping Object

Object whose local coordinates position, rotate, and scale the texture. Leave empty to use world coordinates.

Noise TypeDefault: Perlin

Pattern used to generate procedural mask values.

Perlin: Smooth noise with additional layers controlled by Detail.
Voronoi: Cell-shaped gradients based on distance to the nearest feature point.
Crackle: A pattern emphasizing boundaries between Voronoi cells.
Cell Noise: A constant random value within each grid cell.

ScaleDefault: 2.0

Size of the noise features. Higher values produce broader patterns.

DetailDefault: 2

Number of noise layers used by Perlin noise. Higher values add finer variation.

OffsetDefault: 0.0, 0.0, 0.0

Offset of the coordinates used to sample the noise pattern.

Vertex GroupDefault: activation_mask

Vertex group on the fill mesh used to supply mask weights.

ContrastDefault: 1.0

Adjusts the mask's brightness. Values above 1 darken the mask; values below 1 brighten it.

InvertDefault: Off

Reverses the mask values, turning low values into high values and high values into low values.

Depth BlendDefault: Off

Blends the mask toward Interior Value as distance from the fill mesh's surface increases.

Depth RangeDefault: 0.2

World-space distance from the fill mesh’s surface over which the mask transitions to Interior Value, independent of object scale. Higher values spread the transition over a greater depth.

Interior ValueDefault: 0.0

Target mask value for grains at or beyond Depth Range from the fill mesh's surface. Values above Threshold allow those grains to activate.

Show MaskDefault: Off

Display activation mask values on the grains in grayscale. Brighter values are more likely to exceed the activation threshold.

Tip: Turn off Grains Active to preview the animated mask while keeping the grains still.

Noise, Weight Paint, and Texture are available. Texture uses the fill mesh’s UVs or object/world mapping; image sequences follow scene time. The embedded texture editor exposes image/procedural settings and color-ramp shaping. Object Proximity and Curve Remap are not controls in the Activation Mask panel.

Reference updated 7 November 2026. Defaults describe a fresh setup; saved scenes may use different values.