Colliders

Collider list

1. Use + to add an entry, select it, and assign its mesh in Object.
2. The checkbox in each list row enables or disables that collider. − removes the entry without deleting the source object.
3. Choose the representation, friction, bounce, and margin. Enable Animated for a moving or deforming mesh.

Mesh collision

EnabledDefault: On

Include this collider in the simulation.

Object

Mesh object used to create this collider.

TypeDefault: Triangle Mesh

Geometry used to represent the mesh collider.

• Triangle Mesh: Use the object's evaluated triangle surface, preserving concave features.
• Convex Hull: Use a convex envelope of the object, filling concavities for a simpler collision shape.
• Bounding Box: Use a box aligned to the world axes that encloses the object.

AnimatedDefault: Off

Update this collider from the object’s movement and deformation each frame. When off, it keeps its initial geometry even if other colliders are animated.

MarginDefault: 0.0

Additional contact distance around the collider surface, added to each grain's radius. Higher values keep grains farther from the surface.

FrictionDefault: 0.5

Resistance to grains sliding along this collider. Higher values increase grip.

RestitutionDefault: 0.3

Controls how much grains bounce off this collider. Higher values produce more bounce.

SDF Grid ColliderDefault: Off

Build a collision surface from source points using a sampled distance field.

Triangle Mesh retains concavities; Convex Hull fills them; Bounding Box uses a world-axis-aligned box. For fast moving mesh colliders, see Collider Substeps and Velocity Margin.

SDF Grid Collider

Enable SDF Grid Collider to generate a collision field from source points. This is a field built from vertices or a point cache, rather than the original triangle surface. The Object picker is hidden when Source is Point Cache.

SourceDefault: Object

Where the points used to build the collision field are read from.

• Object: Build the field from the selected mesh object's vertex positions, including its object transform.
• Point Cache: Build the field directly from a Carnage point cache on disk without importing it as an object.

Point Cache

Carnage point cache used to build the collider for each frame. Select its folder, metadata file, or a frame file.

Frame OffsetDefault: 0

Shift point-cache playback in time. Positive values delay the sequence; negative values advance it. Frames outside the cache range hold the first or last frame.

Field ResolutionDefault: 128

Sets voxel size from the source reference bounds: the first cached frame, or the object when the field is first built. Voxel size stays fixed during animation. Higher values capture smaller features and use more memory.

Field RadiusDefault: 0.1

Radius used to blend source points into a collision surface. Higher values connect more widely spaced points and expand the surface.

Surface OffsetDefault: 0.0

Distance to shrink the generated collision surface. Increase this to bring an expanded field closer to its source points.

Fill SolidDefault: On

Fill enclosed empty regions inside the field. Open gaps connected to the outside remain open. Requires additional field-building time and memory.

Preview SDF Field builds a preview of the field. If it cannot be built, the operator reports the error. Keep Surface Offset below Field Radius: an offset as large as the field radius can erase the surface.

Viewport helpers

Show CollidersDefault: Off

Display viewport-only helper geometry representing the mesh colliders used by the simulation. These helpers are excluded from renders.

Collider ColorDefault: 0.0, 1.0, 0.5

Color of the collider helper geometry in the viewport.

Collider OpacityDefault: 0.3

Opacity assigned to the collider helper geometry. Its appearance depends on viewport shading and transparency settings.

Ground

Ground Plane (Z = 0)Default: On

Enable an infinite collision plane at world Z = 0.

Ground FrictionDefault: 0.5

Resistance to sliding between grains and the ground plane. Higher values increase grip. A value of 0 allows frictionless sliding.

Ground RestitutionDefault: 0.3

Controls how much grains bounce when hitting the ground plane. A value of 0 produces no bounce; 1 preserves the incoming speed perpendicular to the ground.