Shows or hides layers: tiles of layers no longer shown leave the surface at once, and the next frames draw only the tiles the new layers add. With SeparateOverlays, toggling the annotation or form-field layer redraws only the overlay tiles; the content tiles stay.
public void SetLayers(DisplayLayers layers)
The layers to show.
Spec #33 viewer capability 6; ISO 32000-2 §12.5 (annotations drawn over the page content).