Model objects can be attached to TimeLiner tasks by dragging and dropping the currently selected items from the Scene View or Selection Tree, or by dragging a search/selection set from the Sets window, and dropping them onto the appropriate task.
Click Home tab > Tools panel > TimeLiner > Tasks tab.
Select the desired item or items in the Scene View, or in the Selection Tree.
Drag and drop the selected items onto the required task in the TimeLiner Tasks tab. Any existing attachments will be overwritten with the dragged items.
Click Home tab > Tools panel > TimeLiner > Tasks tab.
Select the desired set in the Sets window.
Drag and drop the selected set onto the required task in the TimeLiner Tasks tab. Any existing attachments will be overwritten with the dragged sets.