Edit Bar controls: Entry Mode, Rewind, Projection, Angle, Overrun, Radius, Clockwise, Small, Create Duplicate Entities, Palette Group, Palette.
This tool allows you to draw a series of connected lines and arcs, but it may equally well be used to draw a single line or arc.
There are several ways of creating new lines/arcs, controlled by the Entry Mode pull-down list box. The options are:
- 2 Pt. Line; create a line by specifying the start and end points
- 3 Pt. Arc; create an arc by specifying the start point, a point through which the arc passes, and the end point
- 2 Pt. Arc; create an arc tangential to the previous entity by specifying the start and end points
- Arc StartEndRadius; create an arc of specified radius (or diameter) by specifying the start and end points
After the first entity is drawn, subsequent entities start at the end of the previous entity. If you are using 2 Pt. Line mode, after the first pick, the following items may appear on the Edit Bar:
- Projection - allows you to lock the line to a specified angle and draw to an existing entity (plus or minus a specified distance)
- Angle - the angle to be used for the projection
- Overrun - an optional overrun (if positive) or underrun (if negative) distance for the projected line
- Using Projection, you should pick the entity for the projected line to reach. If the new line cannot be projected to the entity (if they are parallel for example) then no new entity is created. The Projection checkbox automatically clears itself, as it is unusual to need to project twice in succession.
If you are using Arc StartEndRadius mode, the following items may appear on the Edit Bar:
- Radius - controls the size of the arc. You can either enter the required radius on the edit bar or use the Nudge keys to adjust the radius interactively.
- Clockwise - determines the direction of the arc
- Small - determines which part of the arc is drawn (less than 180 degrees or more than 180 degrees)
- This mode works very similarly to the ArcStartEndRadius tool.
If you wish to delete the last entity created, click on the Rewind button on the Edit Bar. You cannot do this once you have cancelled the tool.
To start a new series of lines/arcs, not joined to the current series, press the right mouse button and use Restart LineMultiple from the context menu. Similarly, an alternative way to change mode is to choose from the list shown on the context menu.
Constraint Manager
If you have the Constraint Manager active whilst using this tool you will experience the following differences:
- As you add a new line the tool infers for constraints, unless you hold down the Control key; these are applied in the following order of preference:
- Horizontal or Vertical
- Parallel or perpendicular to an existing line
- Normal or tangent to an existing arc, but only if the start or end is coincident with the arc
- These constraints affect the direction of the line - if the line is still flexible then the tool checks for equal length with an existing line
- If the tool successfully infers any of these constraints then it snaps the end of the line into position to satisfy them - if you then add the line the inferred constraint will be applied
- A coincident constraint is added if the new entity starts or ends on an existing entity
Fixed length hotkey
This defaults to '=', but can be configured in the Options > Environment > Keyboard settings.
Whilst adding a new line you can press this hotkey to bring up the Line Length form:
Here you can enter a value, expression or variable for the length. The line is then created and a line length dimension added to it.
Creating arcs
If an arc is added using the 2pt. Arc mode and the arc starts on an existing entity then the start of the arc is tangential to the existing entity so a tangent constraint is added.
If an arc is added using the 3pt. Arc mode and the second click is on a point on an entity then a coincident constraint is added between the new arc and the point.
Related topics: Notes On Draw Tools