Arnold Scatter

The Arnold Scatter object allows you to distribute millions of instances over a selected surface in an efficient way. You can specify the density (number of points per unit of area) or a total number of points on the surface, use vertex maps, or any C4D shaders (e.g. Bitmap, Noise, Gradient, etc.) to control the distribution. You can also utilize the power of Cinema's Effectors to create complex animations.

A video that shows how to use the Arnold Scatter object can be found here.

Arnold Scatter uses the position of the object's pivot to position the object.

Distribution

Surface

The mesh to be scattered. Only poly meshes are allowed currently, splines and volumes are not supported.

Selection

You can distribute instances over the selected vertices/edges/polygons only by specifying a Selection tag.

Distribution

Select from the following distribution methods:

Vertex: Create an instance at each vertex of the mesh.
Edge: Create instances over the edges of the mesh.
Polygon Center: Create an instance at the center of each polygon of the mesh.
Surface: Create instances of the entire surface area.


Vertex	Edge	Polygon Center	Surface

Points Per Edge

Specifies how many instances are created over each edge. Available only in Edge distribution mode.


1	2	4

Uniform Distribution

When enabled instances are uniformly distributed over each edge. Otherwise, the distribution is random. Available only in Edge distribution mode.


Disabled (default)	Enabled

Mode

Select how to control distribution in Surface mode.

Density: The number of instances is defined by the area of the surface. The advantage of this method is to preserve the density of instances after scaling the surface.
Point Count: Specify the exact number of instances on the surface.

Density

Controls the density of instances over the surface. 100% means 1 point per square unit. For instance 10000 instances over a 100x100 cm Plane.


10%	50%	100% (default)

Points per Square Unit

Controls how many points are generated per surface area. For instance, the default 1 cm setting means 1 point on each cm^2.

Max Points

This is an optional strict limit on the number of instances to be generated in Density mode, to avoid fatal accidents, like generating billions or trillions of instances on a huge surface unintentionally, resulting in possible out of memory error.

When the number of points generated based on the density settings exceeds the given Max Points value, a message is displayed on the UI.

Seed

Controls distribution variations in Surface and Edge modes.


1 (default)	2

Shader

You can use any Cinema 4D shader (e.g. Bitmap, Noise, Gradient, etc.) to control the density of instances in texture space via greyscale textures. Black spots mean no instances, white spots mean full density. The texture is used over the above distribution controls.


Shader texture	Objects scattered relative to shader texture

Push apart

When enabled instances are pushed to keep a minimum distance between them.

Distance

The minimum distance between instances when the Push Apart feature is enabled. Two instances (two scattered points on the surface) can not be closer than this value.


10 cm (default)	1000 cm

Instances

Render

Choose where the instances are defined. You can select any object from the scene (custom shapes) or use the child objects as instances.

Custom Shapes

You can use any shapes from the scene to render instances by selecting the custom shapes render mode and adding the shapes to this field.

Shape Mode

If multiple shapes are defined for instancing their order can be specified via the Shape Mode option. The available modes are:

sequential: Shapes in the defined order (as they appear in the Custom shapes field or child order).
random: Uses the Random seed to define a random shape order.
blend: Divides the shapes into equal amounts.
first: Uses only the first shape.

Shape Parameters

See the Geometry Parameters page for further details on common shape parameters.

Orientation

Up Direction

Specifies the up vector (Y) of the instances. Possible options are:

axis: Select the object space axis where the instances point to. For instance +Y means the up vector of the surface.


+X	-X	+Y	-Y	+Z	-Z

normal: Normal vector of the surface is used as the up vector of the instances.
target: Instances point to a specified target object.

Front Direction

Specifies the direction (Z) where the instances look at. Possible options are:

axis: Select the object space axis where the instances point to. For instance +Z means the forward vector of the surface.
camera: Instances point to the active scene camera.
center: Instances point to the center of the surface.
target: Instances point to a specified target object.


Axis	Camera	Center	Target

Off: Display is turned off.
Dots: The scattered points are displayed as dots in the viewport.
Axes: The X, Y, Z axes of each instance are displayed giving you the sense of the orientation of the instances. You can control the length of the axes via the Axis Size parameter.
Bounding Box: Display the bounding box of each instance.
Wireframe: Display a wireframe of each instance.

Shader: Display each instance as shaded mesh.