How Do You Flatten a Spline in AutoCAD?

How Do You Flatten a Spline in AutoCAD?

If you work with AutoCAD, you may already be familiar with splines. Splines are smooth and curvy lines that can be created using control points.

However, there may be instances where you need to flatten a spline to make it straight or simpler for your design requirements. In this tutorial, we will explore how to flatten a spline in AutoCAD.

Step 1: Select the Spline

To begin the process of flattening a spline, you first need to select the spline that you want to flatten. You can do this by using the SELECT command or by clicking on the spline directly.

Step 2: Access the Properties Palette

Once you have selected the spline, you need to access the properties palette. This can be done by right-clicking on the selected spline and choosing Properties, or by typing PROPERTIES in the command line.

Step 3: Change Spline Type

In the properties palette, locate the Spline Type option. By default, it is set to “Fit” which creates a smooth curve passing through all control points.

To flatten the spline, change the Spline Type to “Control Vertices”. This option makes the spline pass through each control point directly without any curves.

Step 4: Adjust Control Points

To further refine and flatten your spline, you may need to adjust the control points manually. You can do this by clicking on each control point and dragging them to new positions until your desired flat shape is achieved.

Step 5: Modify Tangents

If required, you can also modify the tangents of the control points to achieve a specific slope or angle. This can be done by selecting a control point and adjusting its handles.

Step 6: Verify the Flatness

After making all the necessary adjustments, it is important to verify that your spline is now flat. You can do this by zooming in on the spline and checking if there are any visible curves or deviations from a straight line.

Step 7: Save Your Work

Once you are satisfied with the flattened spline, make sure to save your work to avoid losing any changes.

Using these simple steps, you can easily flatten a spline in AutoCAD. Whether you need to simplify complex designs or create straight lines for specific purposes, knowing how to flatten splines will enhance your productivity and precision in AutoCAD.


  • Select the spline you want to flatten
  • Access the properties palette
  • Change the spline type to “Control Vertices”
  • Adjust control points manually as needed
  • Modify tangents if required
  • Verify that the spline is flat
  • Save your work


This tutorial assumes you have basic knowledge of using AutoCAD. Practice these steps on sample drawings before applying them to important projects.


In this tutorial, we discussed how to flatten a spline in AutoCAD. We learned how to change the spline type, adjust control points, modify tangents, and verify flatness. By following these steps, you can easily flatten splines and achieve the desired results in your AutoCAD drawings.