The Spline Deformation allows you to deform an mesh along an axis, using a spline as the target shape.

It has been designed to be used in the Nodal Displacement editor located in the Primitive/Geometry tab of a mesh.

This pop-up allows you to select the spline that's used to deform the geometry.

This defines the axis that's used for the deformation.

Basically, the distance of every vertex to the mesh origin is computed along this axis. That distance is in turn used to find a transformation on the spline. The vertex is then moved accordingly.

If enabled, the mesh will be squashed/stretch to fit the spline. The Offset will be disabled.