# Datum

Create Datum. The annotations created by this command are placed in View Panel - Datum.

Main functions and operation:

Datum label: Used to enter the datum label, with a maximum of 2 Chinese characters/letters/numbers/symbols;
Style: There are 3 options to control the shape of the datum.
Text: Used to add text around the label itself.

When selecting a position in the viewport, you can select points (including sketch points, vertices, and line points), lines (including splines, sketch lines, and edges), and faces.

The bottom end of the reference symbol is located on the reference element.
The imaginary datum on which the datum symbol is located is "a plane parallel to the active view through the point at the base of the datum symbol."
When the base of the base target is changed, the imaginary datum on which the base symbol is located moves accordingly.
When the reference element is a dimension line, the imaginary datum is on the same plane as the dimension line.

The way to determine the position of the datum: You need to click the left mouse button twice

The first click determines the position of the "base element" and the bottom of the base symbol on the base element.
After the first click, move the mouse, and the frame of the reference element follows the mouse on the imaginary datum.
The mouse moves to where you want to place the frame, and the second click, the placement is complete and the annotation is generated.
You can place the datum tag in succession.

Click the completed 3D mark. The 3D mark is highlighted. Hold and drag to change the position. Double-click the 3D mark or right click to edit the 3D mark, the corresponding dialog box pops up, you can edit again.

When it is highlighted, a control point appears at the bottom of the lead for easy picking up. Drag the control point to move the bottom of the lead on the selected base element.
Drag the frame to move the frame's position.

Example:Create a custom view, annotate the datum, as follows.