History

Toolbar	Menu	Status bar
History Main Main2 Tools	Not on menus.	Record History

Toolbar

Status bar

The History command stores the connection between a command's input geometry and the result so that when the input geometry changes, the result updates accordingly.

For example, with History recording and Update turned on, a lofted surface can be changed by editing the input curves.

Steps

In the status bar, click the Record History pane.
- Clicking the Record History pane only records History for the current or next command.
- Right-click the Record History pane and enable Always Record History to record History for all commands that support History.
Use a history-enabled command such as the Loft command to make a surface from input curves.
Edit the input curves.
The surface updates.

Parent and child objects will stay connected if they are cut/copy-pasted, or moved together.

Command-line options
Record	Controls the default Record History setting. In general, it is best to leave the Record option set to No and use the Record History status bar pane to selectively record history. Recording history uses computer resources and makes saved files larger.
OneShotRecord	This option always starts out as "Inactive". Setting to Yes or No controls whether history will be recorded for the next command or not.
Update	Allows output to automatically update when input is edited. This may be slow or may interfere with your workflow. If the option is set to No, use the HistoryUpdate command to manually update the objects.
Lock	Locks child objects created with History to discourage direct geometry editing of the child object. Editing the child object directly will break the history link to the parent object. History locked objects are selectable to use as input and edit properties, but not change geometry. If full locking is needed, children can be selected and locked with Lock command. The selection filter toolbar flashes if you try to select a object that is filtered out. Trying to drag or otherwise transform an object with history now displays the error message, "Unable to transform X history locked objects" if "Lock children" is selected. To temporarily disable History locking in a command session, start the command with "!&". Details...
BrokenHistoryWarning	Displays a warning dialog when an action is taken that breaks the link between the output and input objects. To get back, use the Undo command. Cautions The connection between the input objects and the output object is easily broken. The basic rules for preserving history are: Do not purge the history from the child (output) surfaces. Do not delete the parent geometry (input objects - curves, surfaces, etc.) that was used to create the child surface. Do not control-point edit or move the child surface. Do not move parents and children together. Joining objects breaks history on the objects. History stored in previous versions of Rhino may not carry over to a later version.
RecordAnnotationHistory	Turns History recording on/off for dimension commands. Yes is the default value.

Overriding History Options

The status bar Record History pane reflects the current state of history recording. Click the pane to toggle the global setting for the duration of one command. If the text in the pane is bold, then recording is active, if it is not bold, recording is not active.
Change the option using the History command. This command can be run inside another command. It can also be included in a macro. This setting does not quit after one command. It must be explicitly changed.
History can be recorded without the output geometry being updated when inputs are edited.

Dimensions have History recorded by default. The default History recording behavior is controlled by the RecordAnnotationHistory option in the History command.