Instructions
Drag any of the blue control points to deform the mesh.
Controls
- e: toggle [e]dit mode. (which shows/hides control points)
- r: [r]eset positions of control points
- z: toggle [z]-mode. (in which vertical drags move a point on along the z axis)
Comments
This large mesh is composed of left and right Bezier patches. When any of the shared center control points are moved, the control points to the left and right move by the same amount. Also, when a control point directly to the left or right of the shared center points is moved, the point on the opposite side of the center point moves by the opposite amount. Taken togther, these two rules keep the surface smooth.
Source