Drawing Objects Drawing Objects

IntroductionIntroduction The Draw commands can be used to create new The Draw commands can be used to create new

objects such as lines and circles. Most AutoCAD objects such as lines and circles. Most AutoCAD drawings are composed purely and simply from drawings are composed purely and simply from these basic components. A good understanding of these basic components. A good understanding of the Draw commands is fundamental to the the Draw commands is fundamental to the efficient use of AutoCAD. efficient use of AutoCAD.

The sections to follow cover the most frequently The sections to follow cover the most frequently used Draw commands such as used Draw commands such as LineLine, , PolylinePolyline and and CircleCircle as well as the more advanced commands as well as the more advanced commands like like MultilineMultiline and and Multiline StyleMultiline Style. .

In common with most In common with most AutoCAD commands, the AutoCAD commands, the Draw commands can be Draw commands can be started in a number of ways. started in a number of ways. Command names or short-Command names or short-cuts can be entered at the cuts can be entered at the keyboard, commands can be keyboard, commands can be started from the Draw pull-started from the Draw pull-down menu, shown on the down menu, shown on the right or from the Draw right or from the Draw toolbar. toolbar.

If you are working with the If you are working with the pull-down menus, it is worth pull-down menus, it is worth considering the visual syntax considering the visual syntax that is common to all pull-that is common to all pull-downs used in the Windows downs used in the Windows operating system. For operating system. For example, a small arrow like so example, a small arrow like so " " next to a menu item " " next to a menu item means that the item leads to means that the item leads to a sub-menu that may contain a sub-menu that may contain other commands or command other commands or command options. An ellipses, "…" after options. An ellipses, "…" after a menu item means that the a menu item means that the item displays a dialogue box.item displays a dialogue box.

LinesLines Lines are probably the most simple of AutoCAD objects. Lines are probably the most simple of AutoCAD objects.

Using the Line command, a line can be drawn between any Using the Line command, a line can be drawn between any two points picked within the drawing area. Lines are usually two points picked within the drawing area. Lines are usually the first objects you will want to draw when starting a new the first objects you will want to draw when starting a new drawing because they can be used as "construction lines" drawing because they can be used as "construction lines" upon which the rest of your drawing will be based. Never upon which the rest of your drawing will be based. Never forget that creating drawings with AutoCAD is not so forget that creating drawings with AutoCAD is not so dissimilar from creating drawings on a drawing board. Many dissimilar from creating drawings on a drawing board. Many of the basic drawing methods are the same. of the basic drawing methods are the same.

Anyone familiar with mathematics will know that lines Anyone familiar with mathematics will know that lines drawn between points are often called drawn between points are often called vectorsvectors. This . This terminology is used to describe the type of drawings that terminology is used to describe the type of drawings that AutoCAD creates. AutoCAD drawings are generically AutoCAD creates. AutoCAD drawings are generically referred to as "vector drawings". Vector drawings are referred to as "vector drawings". Vector drawings are extremely useful where precision is the most important extremely useful where precision is the most important criterion because they retain their accuracy irrespective of criterion because they retain their accuracy irrespective of scalescale

The Line CommandThe Line Command With the Line command you can With the Line command you can

draw a simple line from one point draw a simple line from one point to another. When you pick the to another. When you pick the first point and move the cross-first point and move the cross-hairs to the location of the second hairs to the location of the second point you will see a rubber band point you will see a rubber band line which shows you where the line which shows you where the line will be drawn when the line will be drawn when the second point is picked. Line second point is picked. Line objects have two ends (the first objects have two ends (the first point and the last point). You can point and the last point). You can continue picking points and continue picking points and AutoCAD will draw a straight line AutoCAD will draw a straight line between each picked point and between each picked point and the previous point. Each line the previous point. Each line segment drawn is a separate segment drawn is a separate object and can be moved or object and can be moved or erased as required. To end this erased as required. To end this command, just hit the enter key command, just hit the enter key on the keyboard.on the keyboard.

Toolbar: Toolbar: Pull-down: Pull-down: Draw LineDraw Line Keyboard: Keyboard: LINE LINE short-short-

cut: cut: LL

The Line Command, cont.The Line Command, cont.

You can also draw You can also draw lines by entering the lines by entering the co-ordinates of their co-ordinates of their end points at the end points at the command prompt command prompt rather than picking rather than picking their position from the their position from the screen. This enables screen. This enables you to draw lines that you to draw lines that are off screen, should are off screen, should you want to. you want to.

Command SequenceCommand SequenceCommand: LINECommand: LINEFrom point: (pick P1)From point: (pick P1)To point: (pick P2)To point: (pick P2)To point: (to end) To point: (to end)

The Construction Line CommandThe Construction Line Command

The Construction Line The Construction Line command creates a line of command creates a line of infinite length which passes infinite length which passes through two picked points. through two picked points. Construction lines are very Construction lines are very useful for creating useful for creating construction frameworks or construction frameworks or grids within which to design. grids within which to design.

Construction lines are not Construction lines are not normally used as objects in normally used as objects in finished drawings, it is usual, finished drawings, it is usual, therefore, to draw all your therefore, to draw all your construction lines on a construction lines on a separate separate layerlayer which will be which will be turned off or frozen prior to turned off or frozen prior to printing. Because of their printing. Because of their nature, the Zoom Extents nature, the Zoom Extents command option ignores command option ignores construction lines. construction lines.

Toolbar:Toolbar:

Pull-down: Pull-down: Draw Draw Construction LineConstruction Line

Keyboard: Keyboard: XLINE XLINE short-cut: short-cut: XLXL

The Construction Line Command, The Construction Line Command, cont.cont.

Command SequenceCommand SequenceCommand: XLINECommand: XLINEHor/Ver/Ang/Bisect/Offset/<From point>: Hor/Ver/Ang/Bisect/Offset/<From point>: (pick a point)(pick a point)Through point: (pick a second point)Through point: (pick a second point)Through point: (to end or pick another Through point: (to end or pick another point) point)

The Construction Line Command, The Construction Line Command, cont.cont.

You may notice that there are You may notice that there are a number of options with this a number of options with this command. For example, the command. For example, the "Hor" and "Ver" options can "Hor" and "Ver" options can be used to draw construction be used to draw construction lines that are truly horizontal lines that are truly horizontal or vertical. In both these or vertical. In both these cases, only a single pick point cases, only a single pick point is required because the is required because the direction of the line is direction of the line is predetermined. To use a predetermined. To use a command option, simply command option, simply enter the capitalized part of enter the capitalized part of the option name at the the option name at the command prompt. Follow the command prompt. Follow the command sequence to the command sequence to the right to see how you would right to see how you would draw a construction line using draw a construction line using the Horizontal option.the Horizontal option.

Command SequenceCommand SequenceCommand: XLINECommand: XLINEHor/Ver/Ang/Bisect/Offset/Hor/Ver/Ang/Bisect/Offset/<From point>: H <From point>: H

Through point: (pick a Through point: (pick a point to position the line)point to position the line)

Through point: (to end Through point: (to end or pick a point for another or pick a point for another horizontal line) horizontal line)

The Ray CommandThe Ray Command Toolbar: custom Toolbar: custom Pull-down: Pull-down: Draw RayDraw Ray Keyboard: Keyboard: RAYRAY The Ray command The Ray command

creates a line similar creates a line similar to a construction line to a construction line except that it extends except that it extends infinitely in one infinitely in one direction from the first direction from the first pick point. The pick point. The direction of the Ray is direction of the Ray is determined by the determined by the position of the second position of the second pick point. pick point.

Command SequenceCommand SequenceCommand: RAYCommand: RAY

From point: (pick the From point: (pick the start point)start point)

Through point: (pick a Through point: (pick a second point to second point to determine direction)determine direction)

Through point: (to Through point: (to end or pick another end or pick another point) point)

The Polyline FamilyThe Polyline Family Polylines differ from lines in that they are more Polylines differ from lines in that they are more

complex objects. A single polyline can be complex objects. A single polyline can be composed of a number of straight-line or arc composed of a number of straight-line or arc segmentssegments. Polylines can also be given line widths . Polylines can also be given line widths to make them appear solid. The illustrations to make them appear solid. The illustrations below show a number of polylines to give you an below show a number of polylines to give you an idea of the flexibility of this type of line.idea of the flexibility of this type of line.

The Polyline QuandaryThe Polyline Quandary You may be wondering, if Polylines are so useful, You may be wondering, if Polylines are so useful,

why bother using ordinary lines at all? There are why bother using ordinary lines at all? There are a number of answers to this question. The most a number of answers to this question. The most frequently given answer is that because of their frequently given answer is that because of their complexity, polylines use up more disk space complexity, polylines use up more disk space than the equivalent line. As it is desirable to keep than the equivalent line. As it is desirable to keep file sizes as small as possible, it is a good idea to file sizes as small as possible, it is a good idea to use lines rather than polylines unless you have a use lines rather than polylines unless you have a particular requirement. You will also find, as you particular requirement. You will also find, as you work with AutoCAD that lines and polylines are work with AutoCAD that lines and polylines are operationally different. Sometimes it is easier to operationally different. Sometimes it is easier to work with polylines for certain tasks and at other work with polylines for certain tasks and at other times lines are best. You will quickly learn the times lines are best. You will quickly learn the pros and cons of these two sorts of line when you pros and cons of these two sorts of line when you begin drawing with AutoCAD. begin drawing with AutoCAD.

The Polyline CommandThe Polyline Command

Toolbar Toolbar Pull-down: Pull-down: Draw PolylineDraw Polyline Keyboard: Keyboard: PLINEPLINE

short-cut: short-cut: PLPL

The Polyline CommandThe Polyline Command The Polyline or Pline command is similar to the The Polyline or Pline command is similar to the

line command except that the resulting object line command except that the resulting object may be composed of a number of segments may be composed of a number of segments which form a single which form a single objectobject. In addition to the two . In addition to the two ends a polyline is said to have ends a polyline is said to have verticesvertices (singular (singular vertexvertex) where intermediate line segments join. In ) where intermediate line segments join. In practice the Polyline command works in the same practice the Polyline command works in the same way as the Line command allowing you to pick as way as the Line command allowing you to pick as many points as you like. Again, just hit to end. many points as you like. Again, just hit to end. As with the Line command, you also have the As with the Line command, you also have the option to automatically option to automatically closeclose a polyline end to a polyline end to end. To do this, type end. To do this, type CC to use the close option to use the close option instead of hitting . Follow the command instead of hitting . Follow the command sequence below to see how this works. sequence below to see how this works.

Polyline CommandPolyline Command Command SequenceCommand Sequence

Command: PLINECommand: PLINE

From point: (pick P1)From point: (pick P1)

Current line-width is 0.0000Current line-width is 0.0000Arc/Close/Halfwidth/Length/Undo/Width/<Endpoint of line>: (pick P2)Arc/Close/Halfwidth/Length/Undo/Width/<Endpoint of line>: (pick P2)

Arc/Close/Halfwidth/Length/Undo/Width/<Endpoint of line>: (pick P3)Arc/Close/Halfwidth/Length/Undo/Width/<Endpoint of line>: (pick P3)

Arc/Close/Halfwidth/Length/Undo/Width/<Endpoint of line>: (pick P4)Arc/Close/Halfwidth/Length/Undo/Width/<Endpoint of line>: (pick P4)

Arc/Close/Halfwidth/Length/Undo/Width/<Endpoint of line>: (pick P5)Arc/Close/Halfwidth/Length/Undo/Width/<Endpoint of line>: (pick P5)

Arc/Close/Halfwidth/Length/Undo/Width/<Endpoint of line>: (or C to Arc/Close/Halfwidth/Length/Undo/Width/<Endpoint of line>: (or C to close) close)

PolylinesPolylines

In the illustration In the illustration on the right, the on the right, the figure on the left figure on the left was created by was created by hitting the key hitting the key after the fifth point after the fifth point was picked. The was picked. The figure on the right figure on the right demonstrates the demonstrates the effect of using the effect of using the Close option. Close option.

Polyline editingPolyline editing It is worth while taking some time to familiarize It is worth while taking some time to familiarize

yourself with the Polyline command as it is an yourself with the Polyline command as it is an extremely useful command to know. Try extremely useful command to know. Try experimenting with options such as Arc and experimenting with options such as Arc and Width and see if you can create polylines like the Width and see if you can create polylines like the ones in the illustration above. The Undo option is ones in the illustration above. The Undo option is particularly useful. This allows you to unpick particularly useful. This allows you to unpick polyline vertices, one at a time so that you can polyline vertices, one at a time so that you can easily correct mistakes.easily correct mistakes.

Polylines can be edited after they are created to, Polylines can be edited after they are created to,

for example, change their width. You can do this for example, change their width. You can do this using the PEDIT command, using the PEDIT command, Modify Object Modify Object PolylinePolyline from the pull-down menu. from the pull-down menu.

The Rectangle CommandThe Rectangle Command Toolbar Toolbar Pull-down: Pull-down: Draw RectangleDraw Rectangle Keyboard:Keyboard:RECTANGLERECTANGLE short-cuts: short-cuts: REC REC oror RECTANG RECTANG The Rectangle command is used to draw a The Rectangle command is used to draw a

rectangle whose sides are vertical and rectangle whose sides are vertical and horizontal. The position and size of the horizontal. The position and size of the rectangle are defined by picking two rectangle are defined by picking two diagonal corners. The rectangle isn't really diagonal corners. The rectangle isn't really an AutoCAD object at all. It is, in fact, just an AutoCAD object at all. It is, in fact, just a closed polyline which is automatically a closed polyline which is automatically drawn for you. drawn for you.

Rectangle command, cont.Rectangle command, cont. Command SequenceCommand Sequence

Command: RECTANGCommand: RECTANGChamfer/Elevation/Fillet/Thickness/Width/<First corner>: (pick P1)Chamfer/Elevation/Fillet/Thickness/Width/<First corner>: (pick P1)Other corner: (pick P2) Other corner: (pick P2)

The Rectangle command also has a number of options. Width The Rectangle command also has a number of options. Width works in the same way as for the Polyline command. works in the same way as for the Polyline command.

The Polygon CommandThe Polygon Command The Polygon command can be used to draw any regular The Polygon command can be used to draw any regular

polygon from 3 sides up to 1024 sides. This command polygon from 3 sides up to 1024 sides. This command requires four inputs from the user, the number of sides, a requires four inputs from the user, the number of sides, a pick point for the centre of the polygon, whether you want pick point for the centre of the polygon, whether you want the polygon the polygon inscribedinscribed or or circumscribedcircumscribed and then a pick and then a pick point which determines both the radius of this imaginary point which determines both the radius of this imaginary circle and the orientation of the polygon. The polygon circle and the orientation of the polygon. The polygon command creates a closed polyline in the shape of the command creates a closed polyline in the shape of the required polygon. required polygon.

This command also allows you to define the polygon by This command also allows you to define the polygon by entering the length of a side using the Edge option. You can entering the length of a side using the Edge option. You can also control the size of the polygon by entering an exact also control the size of the polygon by entering an exact radius for the circle. Follow the command sequence below radius for the circle. Follow the command sequence below to see how this command works. to see how this command works.

Polygon Command, cont.Polygon Command, cont. Toolbar Toolbar Pull-down: Pull-down: Draw PolygonDraw Polygon Keyboard:Keyboard:POLYGONPOLYGON

short-cut: short-cut: POLPOL

Command SequenceCommand SequenceCommand: POLYGONCommand: POLYGONNumber of sides <4>: 5 Number of sides <4>: 5 Edge/<Center of Edge/<Center of polygon>: (pick P1 or type polygon>: (pick P1 or type E to define by edge E to define by edge length)length)Inscribed in Inscribed in circle/Circumscribed about circle/Circumscribed about circle (I/C) <I>: circle (I/C) <I>: (to accept the inscribed (to accept the inscribed default or type C for default or type C for circumscribed) circumscribed) Radius of circle: (pick P2 Radius of circle: (pick P2 or enter exact radius) or enter exact radius)

Polygon Command, cont.Polygon Command, cont.

In the illustration above, the polygon on the left is In the illustration above, the polygon on the left is inscribed (inside the circle with the polygon inscribed (inside the circle with the polygon vertexes touching it), the one in the middle is vertexes touching it), the one in the middle is circumscribed (outside the circle with the polyline circumscribed (outside the circle with the polyline edges tangential to it) and the one on the right is edges tangential to it) and the one on the right is defined by the length of an edge. defined by the length of an edge.

The Donut CommandThe Donut Command Toolbar: customToolbar: custom Pull-down: Pull-down: Draw DonutDraw Donut Keyboard: Keyboard: DONUTDONUT

short-cut: short-cut: DODO

This command draws a solid This command draws a solid donut shape. AutoCAD asks you donut shape. AutoCAD asks you to define the inside diameter to define the inside diameter i.e. the diameter of the hole i.e. the diameter of the hole and then the outside diameter and then the outside diameter of the donut. The donut is then of the donut. The donut is then drawn in outline and you are drawn in outline and you are asked to pick the centre point asked to pick the centre point in order to position the donut. in order to position the donut. You can continue picking centre You can continue picking centre points to draw more donuts or points to draw more donuts or you can hit to end the you can hit to end the command. Surprisingly, donuts command. Surprisingly, donuts are constructed from single are constructed from single closed polylines composed of closed polylines composed of two arc segments which have two arc segments which have been given a width. Fortunately been given a width. Fortunately AutoCAD works all this out for AutoCAD works all this out for you, so all you see is a donut.you, so all you see is a donut.

Donut Command SequenceDonut Command Sequence

Command: DONUTCommand: DONUTInside diameter <0.5000>:Inside diameter <0.5000>: (pick any two points to define a diameter (pick any two points to define a diameter or enter the exact length)or enter the exact length)Outside diameter <1.0000>:Outside diameter <1.0000>: (pick any two points to define a diameter (pick any two points to define a diameter or enter the exact length)or enter the exact length)Center of doughnut: (pick P1)Center of doughnut: (pick P1)Center of doughnut: Center of doughnut: (to end or continue to pick for more (to end or continue to pick for more doughnuts) doughnuts)

Donut Command Sequence, cont.Donut Command Sequence, cont.

As an alternative to picking two points or As an alternative to picking two points or entering a value for the diameters, you entering a value for the diameters, you could just hit to accept the could just hit to accept the default valuedefault value. . Most AutoCAD commands that require Most AutoCAD commands that require user input have default values. They user input have default values. They always appear in triangular brackets like always appear in triangular brackets like this <default value>. this <default value>.

Circles, Arcs etc. Circles, Arcs etc. Along with Line and Polyline, the Circle command Along with Line and Polyline, the Circle command

is probably one of the most frequently used. is probably one of the most frequently used. Fortunately it is also one of the simplest. Fortunately it is also one of the simplest. However, in common with the other commands in However, in common with the other commands in this section there are a number of options that this section there are a number of options that can help you construct just the circle you need. can help you construct just the circle you need. Most of these options are self explanatory but in Most of these options are self explanatory but in some cases it can be quite confusing. The Circle some cases it can be quite confusing. The Circle command, for example, offers 6 ways to create a command, for example, offers 6 ways to create a circle, while the Arc command offers 10 different circle, while the Arc command offers 10 different methods for drawing an arc. The sections to methods for drawing an arc. The sections to follow concentrate mainly on the follow concentrate mainly on the defaultdefault options options but it is okay to experiment. but it is okay to experiment.

The Circle CommandThe Circle Command

The Circle command is The Circle command is used to draw circles. used to draw circles. There are a number of There are a number of ways you can define ways you can define the circle. The default the circle. The default method is to pick the method is to pick the centre point and then centre point and then to either pick a second to either pick a second point on the point on the circumference of the circumference of the circle or enter the circle or enter the circle radius at the circle radius at the keyboard. keyboard.

Toolbar Toolbar Pull-down: Pull-down: Draw Circle Draw Circle

Center, Radius Center, Radius Keyboard: Keyboard: CIRCLECIRCLE

short-cut: short-cut: CC

Circle Command SequenceCircle Command Sequence

Command: CIRCLECommand: CIRCLE3P/2P/TTR/<Center point>: (pick P1)3P/2P/TTR/<Center point>: (pick P1)Diameter/<Radius>: (pick P2 or Diameter/<Radius>: (pick P2 or enter the exact radius) enter the exact radius)

CircleCircle As you can see from the command prompt above the As you can see from the command prompt above the

default options are always indicated in triangular default options are always indicated in triangular brackets like so <Default> and each brackets like so <Default> and each optionoption is is separated by a forward slash like this /. You can separated by a forward slash like this /. You can choose to use the alternative options by typing them choose to use the alternative options by typing them at the prompt. For example, the circle command gives at the prompt. For example, the circle command gives you three extra options to define a circle. 3P which you three extra options to define a circle. 3P which uses any three points on the circumference, 2P which uses any three points on the circumference, 2P which uses two points on the circumference to form a uses two points on the circumference to form a diameter and TTR which stands for Tangent Tangent diameter and TTR which stands for Tangent Tangent Radius. Obviously to use this last option you need to Radius. Obviously to use this last option you need to have drawn two lines which you can use as tangents have drawn two lines which you can use as tangents to the circle. Try these options out to see how they to the circle. Try these options out to see how they work. There are two more circle options on the pull-work. There are two more circle options on the pull-down menu that enable you to draw a circle by down menu that enable you to draw a circle by defining the center and diameter or by using 3 defining the center and diameter or by using 3 tangents.tangents.

The Arc CommandThe Arc Command The Arc command allows you to draw an The Arc command allows you to draw an

arc of a circle. There are numerous ways arc of a circle. There are numerous ways to define an arc, the default method uses to define an arc, the default method uses three pick points, a start point, a second three pick points, a start point, a second point and an end point. Using this method, point and an end point. Using this method, the drawn arc will start at the first pick the drawn arc will start at the first pick point, pass through the second point and point, pass through the second point and end at the third point. Once you have end at the third point. Once you have mastered the default method try some of mastered the default method try some of the others. You may, for example need to the others. You may, for example need to draw an arc with a specific radius. All of draw an arc with a specific radius. All of the Arc command options are available the Arc command options are available from the pull-down menu. from the pull-down menu.

The Arc CommandThe Arc Command

Toolbar Toolbar Pull-down: Pull-down: Draw Draw

Arc 3 PointsArc 3 Points Keyboard: Keyboard: ARCARC

short-cut: short-cut: AA

Command SequenceCommand SequenceCommand:Command: ARCARCCenter/<Start point>: Center/<Start point>: (pick P1)(pick P1)Center/End/<Second Center/End/<Second Point>: (pick P2)Point>: (pick P2)End Point: (pick P3) End Point: (pick P3)

It is also possible to create an arc by trimming a circle object. In practice, many arcs are actually created this way.

The Ellipse CommandThe Ellipse Command Toolbar Toolbar Pull-down: Pull-down: Draw Ellipse Axis, EndDraw Ellipse Axis, End Keyboard: Keyboard: ELLIPSEELLIPSE

short-cut: short-cut: ELEL

The Ellipse command gives you a number of The Ellipse command gives you a number of different creation options. The default option different creation options. The default option is to pick the two end points of an axis and is to pick the two end points of an axis and then a third point to define the eccentricity of then a third point to define the eccentricity of the ellipse. After you have mastered the the ellipse. After you have mastered the default option, try out the others.default option, try out the others.

Ellipse Command SequenceEllipse Command Sequence

Command: ELLIPSECommand: ELLIPSEArc/Center/<Axis endpoint 1>: (pick P1)Arc/Center/<Axis endpoint 1>: (pick P1)Axis endpoint 2: (pick P2)Axis endpoint 2: (pick P2)<Other axis distance>/Rotation: (pick P3) <Other axis distance>/Rotation: (pick P3)

The ellipse command can also be used to The ellipse command can also be used to draw isometric circles. draw isometric circles.

The Spline CommandThe Spline Command The Spline command creates The Spline command creates

a type of spline known as a a type of spline known as a non-uniform rational B-spline, non-uniform rational B-spline, NURBS for short. A spline is a NURBS for short. A spline is a smooth curve that is fitted smooth curve that is fitted along a number of control along a number of control points. The Fit Tolerance points. The Fit Tolerance option can be used to control option can be used to control how closely the spline how closely the spline conforms to the control conforms to the control points. A low tolerance value points. A low tolerance value causes the spline to form causes the spline to form close to the control points. A close to the control points. A tolerance of 0 (zero) forces tolerance of 0 (zero) forces the spline to pass through the the spline to pass through the control points. The illustration control points. The illustration on the right shows the effect on the right shows the effect of different tolerance values of different tolerance values on a spline that is defined on a spline that is defined using the same four control using the same four control points, P1, P2, P3 and P4. points, P1, P2, P3 and P4.

The Spline CommandThe Spline Command Toolbar Toolbar Pull-down: Pull-down: Draw Draw

SplineSpline Keyboard: Keyboard: SPLINESPLINE short-cut: short-cut: SPLSPL

Splines can be edited Splines can be edited after they have been after they have been created using the created using the SPLINEDIT command, SPLINEDIT command, Modify Object Modify Object SplineSpline from the pull- from the pull-down menu. Using this down menu. Using this command, you can command, you can change the tolerance, change the tolerance, add more control add more control points move control points move control points and close points and close splines, amongst other splines, amongst other things. things.

The Spline Command SequenceThe Spline Command Sequence Command SequenceCommand Sequence

Command: SPLINECommand: SPLINEObject/<Enter first point>: (Pick P1)Object/<Enter first point>: (Pick P1)Enter point: (Pick P2)Enter point: (Pick P2)Close/Fit Tolerance/<Enter point>: (Pick P3)Close/Fit Tolerance/<Enter point>: (Pick P3)Close/Fit Tolerance/<Enter point>: (Pick P4)Close/Fit Tolerance/<Enter point>: (Pick P4)Close/Fit Tolerance/<Enter point>: Close/Fit Tolerance/<Enter point>: Enter start tangent: (pick a point)Enter start tangent: (pick a point)Enter end tangent: (pick a point)Enter end tangent: (pick a point)

You can create linear approximations to splines by smoothing polylines with the PEDIT command. However, you can also turn polylines into true splines using the Object option of the Spline command.