Creating Splines in SOLIDWORKS made easy


Creating organic shapes in SOLDWORKS can be a little intimidating….especially working with splines. After reading this blog, I hope to relieve the anxiety forever! Here are a few tips to help create and manipulate splines easier.

SOLIDWORKS supports two types of splines: B-Splines and Style Splines. These sketch commands are considered to be “sketched curves”. These sketch curves are found in the Sketch Command Manager or under Tools > Sketch Entities > Spline or Style Spline

The definition of a Spline (B-spline): B-Splines are used to create complex curves that have a continuously changed curvature. They are created by placing points through which the curves interpolate its shape. They look like this:


The definition of a Style Spline: This curve is based on Bezier Curve which has a continuously changing curvature and its’ created by locating points of a control polygon which the curve fits within. They look like this:

Style Spline picture

Here are some 4 rules for making splines:

1. Keep it SIMPLE! Too many points will make the manipulating spline handles harder to make the spline smooth. Start with a small number of points. More can be added with a simple Right-Mouse click > Insert Spline Point.

2. Use Curvature Combs tool to see how smooth the spline is. Right-Mouse Click on a curve and select the Show Curvature Combs tool.

Curvature Combs3. Use a 2-point Spline instead. (Doesn’t have any points in the middle). It will look like a straight line until you adjust the spline handles. (Remember, you can always add Spline Points in you need them).

4. Add relations to the handles. To keep a spline handle vertical or horizontal, add the relationship to define its direction.


It is easy to create a spline but the hard part is fine tuning them to get the desired shape. The key is the Spline Handles.

Spline handles control the direction and magnitude for the spline’s curvature at each point.

Let’s take a look at the Anatomy of a Spline Handle.

SPline handles

As you can see, each symbols had a specific purpose and the color also helps determine the spline handles status. Now the guessing game is over. The next time you make splines, try out some of the rules, use the spline controls and you should be rid of Spline anxiety!

Thanks for reading!

Judy Marlo

Application Engineer
Computer Aided Technology, Inc.

One comment on “Creating Splines in SOLIDWORKS made easy

  1. According to your key (which I recognise as coming from the SOLIDWORKS Help system) “You can control the weight of the handles asymmetrically: one side only”. But I find many times if I try to control the weight of one handle, the other one moves too. How do you fix the other one so as to be sure to move them independently?

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