Scatter

V-Ray Scatter creates instances of objects on the surface of a selected object. The most common example is scattering trees and planting on the terrain.

Creating Scatter:

||V-Ray Asset Editor|| > Geometries (right-click) > Scatter

||V-Ray Asset Editor|| > Create Asset (left-click) > Geometries > Scatter

Assigning Scatter:

||Appearance Manager|| > Families tab > Scatter subtab > Add Scatter Host button (right-click) > Pick Face

V-Ray Scatter requires associating with two types of objects:

• the scattered objects, which are referred to as Scatter Guests
• and the object or surface on which the guests are scattered, which is referred to as Scatter Host

V-Ray Scatter is created and filled with guests in the V-Ray Asset Editor. It is then associated with a host from within the Scatter sub-tab of the Appearance Manager Families tab. The scattered objects are visible only at render time.

The V-Ray Scatter asset is found in the Geometry creation menu of the V-Ray Asset Editor.
Once created, use the Add Guests button to add guest(s) to it in one of two ways:

1. In any Revit view, select a family which you want to scatter and press the Add Guests button. It appears in the Guests List below that button.
2. Click the Add Guests button. You are prompted to make a selection. Select a single or multiple families. Click the Finish button at the bottom part of the Revit ribbon to finalize the selection and see the families added to the Guests List.

After Scatter is created and guests are added to it, it needs to be applied to a host object. Adding hosts and associating Scatter with them is explained in the following article.

Click on the gif to enlarge it.

Besides adding guests, V-Ray Scatter's UI in the Asset Editor includes various parameters that affect how the scattered items are rendered in terms of density and orientation.

Scatter – Turns on/off V-Ray Scatter.

Density – Determines the approximate count of instances in a square meter. When a texture is used, the density value can still be used. Black color in the texture discards all instances in the area. Areas colored with white receive maximum density.

Seed – Controls the random seed of the Scatter. Change the integer value and refresh to get a different random distribution.

Axis Filter – Filters the faces that will be used for instance positioning.

All Faces – The points/instances are generated uniformly on all object faces.
Facing Up – The points/instances are only placed on object faces oriented upwards in the scene. Note that host component transformations are ignored.

Orientation – Specifies the initial orientation of the instances.

World Up – All instances are positioned upright independent of the base/host surface face normals.
Along Normals – The instances are oriented based on the base surface face normals.

Collision Detection – When enabled, instances with overlapping bounding boxes are discarded. Eliminating collisions reduces the initial density count and may alter the predetermined ratio between multiple guests.

Add Guests – Adds the currently selected scene objects to the Guests list. The objects in this list are scattered on the base geometry.