Modeling · Beginner

Spline

Any smooth curve that software builds from a handful of control points

What is a spline in 3D?

A spline is a smooth curve that software calculates from a few control points, so you shape a long line by moving a handful of dots. Bezier curves and NURBS are both kinds of spline. In 3D, splines draw paths, outlines and the profiles that surfaces are built from.

Think of it like this

Boat builders once bent a thin, flexible strip of wood around a few pegs to draw a smooth hull line. A spline is that strip, done in software.

Where it fits in a 3D project

  1. Create
  2. Surface
  3. Rig
  4. Animate
  5. Render
  6. Export

Create: Building the shape: modeling, sculpting, scanning or generating it.

How a spline works

  1. 01You place a few control points in the viewport.
  2. 02The software fits a smooth curve through or near them.
  3. 03Moving one point reshapes only the nearby part of the curve.
  4. 04The curve can guide motion, or be swept and lofted into a surface.

Spline vs bezier curve

PropertySplineBezier curve
MeaningA family of smooth, point-driven curvesOne kind of spline
ControlsDepend on the typeAnchors with two handles each
You’ll hear it inAnimation, CAD and modeling generallyDrawing apps and curve tools

Say spline for smooth control-point curves in general; say Bezier curve when you mean the anchor-and-handle type in most drawing tools.

Where a spline is used

  • Motion paths for cameras and objects
  • Roads, rails, cables and fences laid along a line
  • Profiles swept or lofted into bottles, vases and pipes

Beginner tip

If a spline wobbles, delete points rather than adding them. Fewer control points almost always give a smoother, more even curve.

Terms related to a spline

Spline FAQ

What is spline modeling?
Building a model from curves first and filling surfaces between them. You draw outlines and cross-sections as splines, then sweep, loft or patch them into a mesh or NURBS surface. It suits smooth products, vehicles and lettering.
What is a spline in animation?
It usually means the smooth curve the software draws between keyframes. Spline interpolation eases values in and out of each key, which gives natural motion instead of the sudden starts and stops of linear interpolation.
Is a spline a mesh?
No. A spline is a curve with no faces, so it does not render as a surface on its own. Give it thickness, sweep a profile along it, or convert it, and it becomes a mesh.

Updated October 29, 2026 · Browse all 3D terms