Instance primitive and archive geometry

Instance geometry on the surface of polygon objects to create all types of landscapes and environment scenes. XGen includes default spline, sphere, and card primitives as well as a number of geometry objects, such as simple trees and flowers.

You can also instance customized polygon geometry. See Create custom archives from selected objects.

To create hair and fur grooms with XGen, see Create hair and fur with gooming brushes and Create hair or fur with spline primitives.

  1. Select the polygon object or faces of the polygon you want to instance the geometry on.
  2. From the Modeling menu set, select Generate > Create Description.
  3. In the Create XGen Description window, type a New Description Name and, if desired, Collection name.

    XGen Descriptions store settings for positioning, generating, and controlling your instanced geometry. See XGen Descriptions.

    A Collection provides a way of organizing Descriptions and the associated files your Description uses. See XGen Collections.

  4. Under What kind of Primitives are made by this Description?, select the kind of primitive geometry you want to instance.

    If you select Custom Geometry/Archives, you need to select the geometry objects you want instance after you create the Description. See Select the Archive geometry to instance below.

  5. Under Generate the Primitives, select one of the following:
    • Randomly across the surface
    • In uniform rows and columns
    • At points you specify

      Selecting this option lets you specify the location of each geometry object. After creating the Description, use the Specify Points Tool to select these locations. See Add primitives to an existing Description.

  6. Under Control the Primitives by, select one of the following:
    • Placing and shaping guides

      This option lets you place guides on the mesh which you can then scale and shape. When you preview the Description, the guide shapes and positions are applied to the instanced geometry. After creating the Description, use the Add or Move Guides tool to place guides on the mesh. See Shape primitives using XGen guides.

    • Using Attributes controlled by expressions

      Select this option if you do not want to use guides to shape and control primitives. .

  7. Click Create.

    If no Cards or Sphere primitives generate on the mesh surface, you have either created a guides-based Description and need to add the guides using the Add or Move Guides before seeing primitives or Update Preview Automatically is not turned. on. See Preview hair, fur, or instanced geometry.

  8. In the Primitives tab of the XGen Editor, increase Density to generate more primitives.

Select the Archive geometry to instance

If you selected Custom Geometry/Archives, you need to select the archive geometry files you want to instance after you create the Description.

  1. With the new Description selected in the XGen Editor, click the Primitives tab.
  2. In the Archive Files section, selection click Add and browse to the location of the files you want to instance.
Note: Instancing thousands of high resolution archive objects can overload the Graphic Card Processor (GPU). If this occurs, in the XGen Preferences, set Draw method to Legacy for better performance. See XGen Preferences.

Related Tasks

Parent topic: Create Hair, Fur, or Instanced Geometry