Curve Deform

by Kenneth Styrberg

Relevant to Blender v2.35

Introduction

Curve Deform provides a simple but efficient method of defining a deformation on a mesh. By parenting a mesh object to a curve, you can deform the mesh up or down the curve by moving the mesh along, or orthogonal to, the dominant axis.

The Curve Deform works on a dominant axis, X, Y, or Z. This means that when you move your mesh in the dominant direction, the mesh will traverse along the curve. Moving the mesh in an orthogonal direction will move the mesh object closer or further away from the curve. The default settings in Blender map the Y axis to the dominant axis. When you move the object beyond the curve endings the object will continue to deform based on the direction vector of the curve endings.

Tip

Try to position your object over the curve while moving it around. This gives the best control over how the deformation works.

Interface

When parenting a mesh to a curve (CTRL-P), you will be presented with a menu, Figure 9.37, “Make Parent menu.”. By selecting Curve Deform you enable the Curve Deform function on the mesh object.

Figure 9.37. Make Parent menu.

Make Parent menu.

The dominant axis setting is set on the mesh object. By default the dominant axis in Blender is Y. This can be changed by selecting one of the Track X, Y or Z buttons in the Anim Panel, Figure 9.38, “Anim settings panel.”, in Object Context (F7).

Figure 9.38. Anim settings panel.

Anim settings panel.

Cyclic curves work as expected where the object deformations traverse along the path in cycles.

CurveStretch provides an option to let the mesh object stretch, or squeeze, over the entire curve. This option is in Edit Context (F9) for the curve. See Figure 9.39, “Curve and Surface panel.”.

Figure 9.39. Curve and Surface panel.

Curve and Surface panel.

Example

Let's make a simple example.

1. Remove default cube object from scene and add a Monkey! (SHIFT-A -> Add -> Mesh -> Monkey, Figure 9.40, “Add a Monkey!”).

Figure 9.40. Add a Monkey!

Add a Monkey!

2. Now press TAB to exit EditMode. Now add a curve. (SHIFT-A -> Add -> Curve -> Bezier Curve, Figure 9.41, “Add a Curve.”).

Figure 9.41. Add a Curve.

Add a Curve.

3. While in EditMode, move the control points of the curve as shown in Figure 9.42, “Edit Curve.”, then exit EditMode, (TAB).

Figure 9.42. Edit Curve.

Edit Curve.

4. Select the Monkey, (RMB), and then shift select the curve, (SHIFT-RMB). Press CTRL-P to open up the Make Parent menu. Select Curve Deform. (Figure 9.37, “Make Parent menu.”).

The Monkey should be positioned on the curve as Figure 9.43, “Monkey on a Curve.”.

Figure 9.43. Monkey on a Curve.

Monkey on a Curve.

5. Now if you select the Monkey, (RMB), and move it, (G), in the Y-direction, (the dominant axis by default), the Monkey will deform nicely along the curve.

Tip

If you press MMB while moving the Monkey you will constrain the movement to one axis only.

6. In Figure 9.44, “Monkey deformations.”, you can see the Monkey at different positions along the curve. To get a cleaner view over the deformation I have activated SubSurf with Subdiv 2 and Set Smooth on the Monkey mesh. (F9 to get Edit options).

Tip

Moving the Monkey in directions other than the dominant axis will create some odd deformations. Sometimes this is what you want to achieve, so you'll need to experiment and try it out!

Figure 9.44. Monkey deformations.

Monkey deformations.