Groups and rasterization

Some operations, as well as the application of specific filters or a mask, cause a group to be rasterized. When a group is rasterized, it’s converted into a bitmap image. This affects how the rasterized group interacts with other objects in the project.

Rasterization affects 2D and 3D groups in different ways. When a 2D group is rasterized, the blend modes on objects in the group no longer interact with objects outside the group. When a 3D group is rasterized, the group as a whole can no longer intersect with objects outside the group. The rasterized 3D group is treated as a single object and uses layer order (in the Layers list), rather than depth order when composited in the project. (For more information on layer order versus depth order, see Create 3D intersection.)

When a group is rasterized, cameras and lights in the project still interact with objects in the rasterized group.

Important: Lighting in a flattened 3D group does not pass beyond the boundaries of that group, whether rasterized or not.

The following operations on a 2D group trigger the rasterization of that group:

  • Making Blending changes (to the Opacity, Blend Mode, or Preserve Opacity parameters)

  • Turning on the Drop Shadow parameter

  • Turning on the Four Corner parameter

  • Turning on the Crop parameter

  • Applying any filter

  • Adding a mask

  • Adding a light (if the 2D group the light is added to is nested in a 3D group)

The following operations on a 3D group trigger the rasterization of that group:

  • Making blending changes

  • Applying specific filters

    For more information, see Filters and rasterization.

  • Adding a light to a 3D project with the Flatten parameter enabled (in the Group Inspector)

When an operation triggers a rasterization on a group, the following occurs:

  • A rasterization indicator (a small red box containing an “R”) appears next to the parameter in the Properties Inspector.

    Rasterization indicator in Properties Inspector
  • A small outline surrounds the rasterized group in the Layers list and Timeline. This is called a rasterization frame.

    Layers list showing rasterization frame

Unlike vector graphics, rasterized 2D groups may lose quality when scaled if the Fixed Resolution checkbox is selected in the Group Inspector.

Important: 3D particle emitters, 3D replicators, and nonflattened text objects are treated as 3D groups for rasterization.

To learn more about how rasterization affects different types of objects, choose a topic in the Help table of contents (the sidebar to the left of this window).