Notch Reference Manual

Collision Affector

Method

This node simulates collisions between particles and a 3D object. It uses ray traced intersections with triangles contained in a bounding volume hierarchy structure. This allows for fast, accurate collisions with 3D objects, but animating, generated or deforming objects are not supported. They may move in 3D space but must be rigid.

At least one 3D Object Node must be connected via the Object Nodes input for this node to be effective.

Example
Example Nodegraph

Attributes

Name Description
Collision Velocity Scale Scales the velocity of the particle after a collision so they can be made to slow down.
Point Collision Radius Radius around a particle in which it will calculate colliding.
Mode Chang how the calculations against mesh edges are calculated.
  • Thin Mesh, The mesh faces are treated as a thin edge, and calculations are calculated against the face. Fast, but occasionally inaccurate.
  • Extruded Mesh, The mesh faces are extruded along an axis, and the collisions are calculated against the volume. Slow, but more accurate.
Flip Normals Flip the normals of the input object, so collisions are calculate for other side of the face normals.
Double Sided Calculate collisions for both sides of the objects normals.
Dynamic Collision Objects Recalculate collisions each frame for an animating mesh.
Extrude Axis Which axis the mesh has been extruded along.

Inputs

Name Description Typical Node Input
Object Node Object with which the particles collide. 3D Object
Collision Event Nodes Particle events to be triggered when collisions occur. Particle Event
Affected Emitters Choose which emitters can be affected by the affector. Primitive Emitter
Procedural Falloff Use the SDF values from a procedural system to dictate the falloff. Procedural Root
Transform Modifier Links all transform properties to the input node. Null
Target Node Always faces the x-axis towards the inputs anchor point. Null
Local Transform Override Override the transformation values of the node, relative to its parent. Null

Outputs

All nodes connected to this node are treated as if flowing to the parent node, and inherits any transformation changes along the chain.