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Draw and edit CAD-like lines and arcs

How to create and edit special keypoint line and arc objects.

Draw keypoint lines and arcs

How to draw CAD-like keypoint lines and arcs.

Draw a single line

Choose Curves > Lines > Line .
Click the start and end points.

Draw a series of connected lines (polyline)

Choose Curves > Lines > Polyline .
Click the points of the polyline.
Do any of the following:
Click an endpoint of an existing keypoint object to connect this polyline to it.
Choose the Polyline tool again to start another polyline.
Choose any other tool to finish the polyline.

Draw alternating lines and arcs

Choose Curves > Line-arc .
Click the start and end points of the first line segment.
Do any of the following:
Click an endpoint of an existing keypoint object to connect this polyline to it.
Choose the Line-arc tool again to start another keypoint curve.
Choose any other tool to finish the keypoint curve.

Click the endpoint of a segment twice to make the next segment the same type (line or arc). For example, click the endpoint of a line segment twice to make the next segment a line also.

Draw a three-point arc

Choose Curves > Arcs > Arc (three point) .
Click the start point of the arc.
Click a point that will lie on the arc.
Click the end point of the arc.

Draw a two-point arc

Choose Curves > Arcs > Arc (two point) .
Click the start and end points of the arc.
Click the center point of the arc, or type the radius and press .

What if...?

] I want to edit the coordinates or length after I create a line?

Choose Windows > Information > Information window and change the parallel distance or angle.

The relationships between keypoint curves are maintained until you manually reshape one of the curves.

] I want to draw arc segments at a different angle to the last line segment?

Arc segments always project "forward" from the previous line. You cannot create concave arcs with the Line-arc tool.

To get concave arcs, you must go back and edit the curve after creating it.

] I want to export keypoint curves to IGES?

Key lines are exported as entity 110 (line).
Key arcs are exported as IGES entity 100 (circular arc).
Composite curves are exported as entity 102 (composite curve).

Draw a keypoint rectangle

Use the Rectangle tool to create a keypoint rectangle that maintains its shape as you move its keypoints.

Draw a rectangle

Choose Curves > Primitives > Rectangle .
Click to place one corner of the rectangle.
Click to place the opposite corner.

To edit the rectangle, use the Transform > Drag keypoints to move the corners, sides, or center.

Draw keypoint lines parallel or at an angle to existing curves

How to draw a keypoint line that is parallel to an existing curve, or at a specific angle to an existing curve.

Draw a line parallel to a curve

Choose Curves > Lines > Parallel line .



Click the curve to which the new line will be parallel.

If you click a curved line, the new line will be parallel to the tangent where you click.



Click the start and end points of the parallel line.

Draw a line at an angle to a curve

Choose Curves > Lines > Line at angle .



Click the start point, on the curve from which it will angle off.

If you click a curved line, the new line will be drawn at an angle to the line that passes through the end point of the curve.



Type an angle to create a guideline along which you can snap the end point.



Click to place the end point of the line.

What if...?

] I want to edit the coordinates, parallel distance, or angle after I create a line?

Choose Windows > Information > Information window and change the parallel distance or angle.

The relationships between keypoint curves are maintained until you manually reshape one of the curves.

Draw keypoint tangent or perpendicular to existing curves

How to draw a keypoint line from the tangent at some point on an existing curve or between two curves, or perpendicular to some point on an existing curve.

Do not use the tangent line tools in the perspective window.

Draw a line tangent to a curve

Choose Curves > Lines (Tangent) > Line tangent to curve .
Click the start point.
Click the curve you want the line to be tangent to.

If the tool cannot find a tangent, it prints a message in the prompt line.

If the tool finds more than one tangent, it uses the tangent closest to where you clicked.

Draw a tangent line between two curves

Choose Curves > Lines (Tangent) > Line tangent from/to curve .
Click the two curves between which you want to draw a tangent.

If the tool cannot find a tangent, it prints a message in the prompt line.

If the tool finds more than one tangent, it uses the tangent closest to where you clicked.

Draw a line perpendicular to a curve

Choose Curves > Lines (Tangent) > Line perpendicular to curve .
Click the start point.
Click the curve you want the line to be perpendicular to.

If the tool cannot find a perpendicular, it prints a message in the prompt line.

If the tool finds more than one perpendicular, it uses the perpendicular closest to where you clicked.

In an orthographic window, the perpendicular is relative to the view. In a perspective window, it is a 3D perpendicular.

What if...?

] I want to edit the coordinates, parallel distance, or angle after I create a line?

Choose Windows > Information > Information window and change the parallel distance or angle.

The relationships between keypoint curves are maintained until you manually reshape one of the curves.

] The tool does not create a true 3D tangent?

The tangent lines are only tangent in the current view. It is only a true 3D tangent if the curve and start point are planar.

To get a true 3D tangent, use the Line tool with curve snapping to place the first point on the curve, then snap to the tangent guideline.

Draw a keypoint circle or ellipse

How to draw a keypoint circle or ellipse.

Draw a keypoint circle

Choose Curves > Primitives > Circular arc .
Click the center point and a point that will lie on the circle.

Draw an ellipse from the center

Choose Curves > Primitives > Ellipse .
Set Ellipse Definition to Center and end point, then click Go.
Click the center point and the end point.

To draw a keypoint ellipse end-to-end

Choose Curves > Primitives > Ellipse .
Set Ellipse Definition to Axis endpoints, then click Go.
Click the two long-axis end points of the ellipse.

Draw keypoint arcs in relation to existing curves

How to draw a keypoint arc tangent to a point on an existing curve, or concentric to an existing arc.

Draw an arc tangent to a curve

Choose Curves > Arcs > Arc tangent to curve .



Click the start point of the new arc on the curve it will be tangent to.



Click the end point of the arc.

Draw an arc concentric to another arc

Choose Curves > Arcs > Concentric arc .
Click the arc from which the new arc will be offset.



Click the start point and end points of the arc.

What if...?

] I want to create a concentric arc of more than 180 degrees?

Concentric arcs are usually drawn in the direction that will create the smallest sweep angle.

To draw an arc in the opposite direction, choose Windows > Information > Information window . Open the Attributes section and click Complement.

] I want to create a concentric circle?

Choose Windows > Information > Information window . Set the Angle/Sweep attribute to 360.

Edit keypoint curves

How to move, reshape, and edit keypoint curves.

Move a keypoint

Choose Transform > Drag keypoints .
Drag a keypoint to move it.

If you edit a keypoint curve that is maintaining a relationship with another curve (such as tangency), the relationship will be lost.

Edit the attributes of a keypoint curve

Pick the keypoint curve.
Choose Windows > Information > Information window .
Open the Attributes section and edit the settings.

Split a keypoint curve

Choose Curve Edit > Cut > Break curve at keypoint .



Click a keypoint on a keypoint curve.

Work with, limit, or delete guidelines

How to control the guidelines generated by the keypoint curve tools.

Show or hide all guidelines

Choose WindowDisplay > Toggles > Guidelines .

To delete all guidelines

Choose Delete > Delete guidelines .

Limit the number of guidelines allowed on screen

Choose Delete > Delete guidelines  .
Set the maximum number of guidelines you want on screen.

What if...?

] I want to create guidelines when drawing normal NURBS curves?

Open the options box for the curves tool, and turn on the Create Guidelines option.