BREAK - JOIN

Okay, now let us add some window openings in our walls. You can do this with combination of Line, Offset, Trim and Extend commands alright, but wait! When a window is inserted in a wall, the lines perpendicular to the wall lines (vertical edges of window in the elevation) would be section lines while the wall lines running the length of the window would be elevation lines as that would be below the SECTION PLANE. To show this differentiation we need to BREAK the wall lines at appropriate points.

You can break an object into two objects with or without a gap between them. You can also join objects to make a single object.

Break
Use break to create a gap in an object, resulting in two objects with a gap between them. BREAK is often used to create space for block or text. To break an object without creating a gap, specify both break points at the same location. The fastest way to do this is to enter @0,0 at the prompt for the second point.

You can create breaks in most geometric objects except
· Blocks
· Dimensions
· Mlines
· Regions
Command line: break
Select object: Use an object selection method, or specify the first break point (1) on an object
The prompts that are displayed next depend on how you select the object. If you select the object by using your pointing device, the program both selects the object and treats the selection point as the first break point. At the next prompt you can continue by specifying the second point or overriding the first point.
Specify second break point or [First point]: Specify the second break point (2) or enter f
Second Break Point
Specifies the second point to use to break the object.
First Point
Overrides the original first point with the new point that you specify.
Specify first break point:
Specify second break point:The portion of the object is erased between the two points that you specify. If the second point is not on the object, the nearest point on the object is selected; therefore, to break off one end of a line, arc, or polyline, specify the second point beyond the end to be removed.

To split an object in two without erasing a portion, enter the same point for both the first and second points. You can do this by entering @ to specify the second point.

Lines, arcs, circles, polylines, ellipses, splines, donuts, and several other object types can be split into two objects or have one end removed.

The program converts a circle to an arc by removing a piece of the circle starting counterclockwise from the first to the second point.
In case you break any object wrongly or you deliberately want to combine two or more objects to form a single object you can JOIN them if the meet the criterion for this.

Join
Use JOIN to combine similar objects into a single object. You can also create complete circles and ellipses from arcs and elliptical arcs. You can join
· Arcs
· Elliptical arcs
· Lines
· Polylines
· Splines

The object to which you want to join similar objects is called a source object. Objects to be joined must be located in the same plane.

Note – When joining two or more arcs (or elliptical arcs), the arcs are joined counterclockwise beginning from the source object.

Command line: join
Select source object: Select a line, polyline, arc, elliptical arc, or spline
Depending on the source object selected, one of the following prompts is displayed:
Line select lines to join to source: Select one or more lines and press ENTER
The line objects must be collinear (lying on the same infinite line), but can have gaps between them.
Polyline select objects to join to source: Select one or more objects and press ENTER
The objects can be lines, polylines, or arcs. The objects cannot have gaps between them, and must lie on the same plane parallel to the UCS XY plane.
Arc select arcs to join to source or [cLose]: Select one or more arcs and press ENTER, or enter L
The arc objects must lie on the same imaginary circle, but can have gaps between them. The Close option converts the source arc into a circle.

Note – When joining two or more arcs, the arcs are joined counterclockwise beginning from the source object.

Elliptical Arc select elliptical arcs to join to source or [cLose]: Select one or more elliptical arcs and press ENTER, or enter L
The elliptical arcs must lie on the same ellipse, but can have gaps between them. The Close option closes the source ellipstical arc into a complete ellipse.

Note – When joining two or more elliptical arcs, the elliptical arcs are joined counterclockwise beginning from the source object.

Spline select splines to join to source: Select one or more splines and press ENTER
The spline objects must lie in the same plane, and must be contiguous (lying end-to-end).

Tomorrow we will add some Doors to our layout. Stay tuned...!