Notch Notch Manual 0.9.23
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Object Distance Field Affector

Object Distance Field Affector

Apply forces to particles from mesh surfaces.



Method #

This node simulates forces between particles and a 3D object. It uses signed distance fields to interact with the particles, which enables some complex effects to be achieved, such as attraction and repulsion from object surfaces, making particles flow around the particle surface, or simple Particle collisions with mesh surfaces.

Particle Events may be triggered when collisions occur. This allows effects such as particles changing colour, size or material on collision, or emitting new particles at the point of collision.

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


These properties control the core behaviours of the node.

ModeChoose how the node interacts with the input object.
  • Attractor : Moves the particles towards the mesh.
  • Repel : Moves the particles away from the mesh.
  • Collision : Particles collide with the object and bounce off.
  • Follow Contours : Particles flow around the surface of the object.
RadiusLimit the radius at which particles can be affected by the affector.
Life Effect CoeffsHow much the particles are affected by the affector at different stages of the particles life cycle. Values 1 and 2 are control points used to control a bezier curve between values 0 and 3.
Colour WeightControls how much the colour value generated by the affector is blended with the particle’s current colour.
Collision Velocity ScaleScales the velocity of the particle after a collision so they can be made to slow down.
Is Inside ThresholdDistance inside or outside the object at which collisions are considered to have occured.
Surface Distance TargetThe radius of the particle when determining collisions.
On Surface Velocity ScaleScales the velocity of the particle when it is on the surface of the object.
Collision Event LikelinessControls for what fraction of collisions a collision event should be triggered.
Use ColoursToggle whether to use the colours input by the mesh.
Invert SpaceInvert the object so areas inside the mesh are considered hollow and areas outside are filled.
Allow AnimationToggle whether to allow animation in the mesh to be accounted for with the affector.
SDF WidthThe depth in pixels of the signed distance field 3D voxel texture.
SDF HeightThe height in pixels of the signed distance field 3D voxel texture.
SDF DepthThe width in pixels of the signed distance field 3D voxel texture.


NameDescriptionTypical Input
Object NodesThe source meshes for the particles to be affected by.3D Object
Animated SDF Bounding BoxBounding box to specify the size of the input object if it is animating or deforming.Bounding Box
Affected EmittersChoose which particle emitters can be affected by the affector.Primitive Emitter
Procedural FalloffUse the distance field from a procedural system to vary how strong the affector is.Procedural Root
Transform ModifiersApply the transforms of another node to this node.Null
Target NodeModifiy the rotations of the node to always direct the z axis towards the input.Null
Local Transform OverrideApply the transforms of another node to this node, relative to its parent.Null