add
Add a marker to the end of the current scene's marker list. Markers name points or spans on the scene timeline. Several markers may share a name. Experimental: this API may change in a minor release.
Parameters
name
the name of the marker.
time
the start of the marker in seconds. Must be finite and not negative.
duration
the length of the marker in seconds. Must be finite and not negative. 0 marks a single point.