Collider

Set up a mesh as an external collider for simulation nodes.

Inputs

Geometry

The collider geometry.

Deforming

Should be enabled if the collider geometry is deforming over time. In this case each point of the collider is interpolated individually.

If the geometry is not deforming then this option can be disabled for improved performance. This is also possible when the surface is transformed as an instance without changing local positions.

Boundary

Changes behavior such that colliding geometry is kept inside the collider instead of outside.

Edge Contacts

Enable contact detection between simulated geometry and collider mesh edges. This prevents intersection in case of thin geometry and/or colliders with sharp angles.

Without edge contacts edges can pass through faces as long as the end points are outside the collider. On smooth colliders this effect may not be noticeable. In this case edge contacts can be disabled for improved performance.

Warning

Edge contacts are currently only supported for curve geometry (hair simulation).

Margin

Additional collision offset from the surface to avoid penetration.

Friction

Coefficient for static and dynamic friction. Small friction coefficients model a slippery material while larger values create sticky behavior.

The exact meaning of the coefficient can be understood as the tangent of the friction angle (wikipedia): When the angle of the contact force to the surface normal is small the contact is in static friction and sticks the surface. Once the contact force exceeds the friction angle it enters dynamic friction and slows down proportional to the tangential velocity.

Softness

Allow soft collision by correcting positions proportional to penetration depth.

Filter

Comma-separated list of filter tags this collider should apply to. Only simulated geometries with at least one matching tag will collide with it.

Debug

Error Threshold

Threshold for computing relative error contribution. The relative error of a contact is 1 or less when the contact penetration is less than this threshold after applying the solver.

Outputs

Geometry

The input geometry with additional collider information attached.