Chaos Scatter is a powerful instancing and distribution tool that allows you to easily populate scenes with selected objects. This is especially useful for outdoor scenes that need to be filled with greenery, rocks, grass etc.

See the video for an example workflow.

To use Chaos Scatter within Maya, go to the V-Ray shelf and click the Chaos Scatter button.

Add your target object in the Targets Objects field. These are the objects that have models scattered over them.

Then, add the scattering object into the Models field - this is the model that scatters over.

You'll see the result immediately in the viewport.

Targets * – Specifies the object(s), on which the instances are scattered. Targets can be mesh objects, curves (including splines) and proxies.

Factors – This option is only available when On Surfaces scattering is set to Random distribution or the scattering mode is set to 3D - In Bounding Box. Determines how many instances are scattered on the currently selected Targets object(s). Note that for the Factors option to work correctly, you need at least two target objects.

Models * – Specifies the objects which are scattered on the Targets object(s). Models can be mesh objects, proxies, Volume Grid, and lights.

Frequencies – This option is only available when there are more than one Models objects. Determines the frequency of the currently selected instanced object in relativity to the others.

Enable – Enables scattering.

Scatter Type – Specifies in which mode scattering is applied.

1D - On Curves – Scattering mode where objects are scattered along curves. Open or closed curves can be used for this.
2D - On Surfaces – Scattering mode where objects are scattered on surfaces. It doesn't matter if the surface is horizontal, vertical, or part of a complex 3D object. Closed splines can also be used in this mode. In that case, instances are distributed in the area enclosed by the spline.
3D - In Bounding Box – Scattering mode where objects are scattered inside the object's bounding box. Keep in mind that bounding boxes are cube-shaped; therefore, using this mode on a round object scatters instances in a cube around it. This mode is useful when scattering dust particles inside a room, fish in an aquarium, books on a bookshelf, and similar.

Seed – Determines the random distribution used. Changing this value causes random permutations of the scattered objects(s).

Temporal Consistency – When enabled, instances are scattered in the selected Rest-pose Frame and stick to the surface, even if they get deformed in other frames. Otherwise, instances get scattered in each frame separately, which might cause anomalies. Note that Temporal Consistency does not work in IPR yet.

Rest-pose Frame – Determines the initial frame, where the instances are scattered for all following frames. The specified frame with Rest-pose must correspond to the first frame of the animation.

Avoid Collisions – When enabled, instances colliding with each other get discarded. This results in no overlaps between instances. Note that enabling this option might lower the number of instances.

Avoid Collisions Spacing – Controls the bounding boxes' size to detect collisions. Smaller values result in denser instances with some collision; higher values result in larger distances between instances. Values above 1 mean the distance between objects is larger than their bounding boxes.

Convert to Maya instances – Instanced geometry is converted into separate, modifiable objects by pressing this button. It is compatible with Maya geometry and lights, V-Ray lights and proxy meshes. After conversion, all objects are grouped in the Outliner, allowing for individual selection.

vrayBakeScatterInstances ChaosScatterShape1;

maya.cmds.vrayBakeScatterInstances('ChaosScatterShape1')

setAttr ChaosScatterShape1.v 1

Preview Type – Determines the way the instances are displayed in the viewport. This is not reflected when rendering.

None – Nothing is displayed in the viewport.
Point – Displays each instance as a point.
Wire Box – Displays each instance as a wireframe of a box.

Random Color by Model – Every model is assigned a random color, which is then used for every instance of that model.

Preview Instance Limit – Specifies the maximum number of instances displayed in the viewport.

Instance Count Limit – Limits the maximum number of instances. Note that this option does not determine how many instances are created. Instead it serves as a measure to avoid scattering too many instances and causing a crash.

Use Local Rayserver – Changes the scatter type internally. For certain use cases when displacement is used, it can make rendering faster.