How to Draw Spline in AutoCAD: Step-by-Step Guide

To draw a spline in AutoCAD, use the SPLINE command, then click points to define the curve's shape. Press Enter to finish the spline. This creates a smooth, flexible curve passing through or near the points you select.

Syntax

The basic syntax to draw a spline in AutoCAD is:

• SPLINE - Starts the spline drawing command.
• Specify points - Click or enter coordinates to define the curve shape.
• Enter - Ends the spline command and creates the curve.

You can also specify options like fit points or control vertices during the command.

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Command: SPLINE
Specify start point or [Fit points/Control vertices]: (click or type point)
Specify next point: (click or type point)
...
Press Enter to finish

Output

A smooth spline curve appears passing through or near the specified points.

Example

This example shows how to draw a spline passing through three points in AutoCAD:

1. Type SPLINE and press Enter.
2. Click the first point (e.g., 0,0).
3. Click the second point (e.g., 5,5).
4. Click the third point (e.g., 10,0).
5. Press Enter to finish the spline.

The spline will smoothly curve through these points.

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Command: SPLINE
Specify start point or [Fit points/Control vertices]: 0,0
Specify next point: 5,5
Specify next point: 10,0
Press Enter to finish

Output

A smooth curved spline passing through points (0,0), (5,5), and (10,0) is drawn.

Common Pitfalls

Common mistakes when drawing splines in AutoCAD include:

• Not pressing Enter to finish the spline, leaving the command active.
• Clicking points too close together, causing unexpected curve shapes.
• Confusing fit points with control vertices, which affect how the curve passes through points.
• Trying to draw splines on locked layers or with incompatible settings.

Always ensure you finish the command and choose the right points for your desired curve.

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Wrong way:
Command: SPLINE
Specify start point or [Fit points/Control vertices]: 0,0
Specify next point: 0,0.1
Specify next point: 0,0.2
Press Enter

Right way:
Command: SPLINE
Specify start point or [Fit points/Control vertices]: 0,0
Specify next point: 5,5
Specify next point: 10,0
Press Enter

Output

Wrong way creates a nearly straight or jagged line; right way creates a smooth curve.

Quick Reference

Step	Action	Description
1	Type SPLINE	Starts the spline drawing command
2	Specify points	Click or enter points to shape the curve
3	Press Enter	Ends the command and creates the spline
Tip	Use Fit points	Spline passes exactly through these points
Tip	Use Control vertices	Spline shape controlled but may not pass through points

Key Takeaways

Use the SPLINE command and click points to draw smooth curves in AutoCAD.

Press Enter to finish the spline and see the curve created.

Choose fit points to make the spline pass through points exactly.

Avoid placing points too close to prevent unexpected curve shapes.

Always check layer and command status before drawing splines.