API reference / Common / Engine types / GroupObject

Interface: GroupObject

A lightweight scene-tree wrapper — a marked-content sequence around its children, and a clip / soft-mask scope they share, with its own coordinate space.

GroupObject is NOT a PDF transparency group; children composite directly onto the parent backdrop. The transparency-group semantics (isolated, knockout, blend color space) live on Form.transparency_group because they are a property of the Form XObject's /Group attribute, not of the scene-tree container.

The owning [GraphicsObject]'s transform and clips describe the group's coordinate space, and its marked_content is the sequence around the children; soft_mask lives here so multiple children can share one mask scope. Children's transforms are relative to the group's coordinate space.

The importer should not emit single-child groups — flatten them at close time so surviving groups have zero or ≥2 children — unless the group and its child each carry a sequence of their own.

Properties

Property	Type
softMask	string | null
children	GraphicsObject[]