Warp > Twist Operation > To Twist Geometry
  
To Twist Geometry
1. Click Warp > to open the Twist tab and to display the marquee for the geometry.
2. Click until the axis aligns in the direction that you want to twist the geometry.
3. If required, click to reverse the direction of the twist axis.
4. Type a value for the twist angle in the Angle box on the tab, or drag the twist handle.
5. To adjust the region of deformation, drag the faces of the marquee or click the Marquee tab and set the following options:
References—Select optional references for the marquee.
Active Axis—Type Start and End values to determine the size of the marquee. The range depends on the Marquee Size type that you selected.
Marquee Size—Select a method of measurement to set the dimensions of the active axis.
 
* When you choose an Absolute type for the marquee size and make use of optional references, you cannot change the marquee's length. To change the length, edit the referenced object outside of the Warp feature.
6. Click Center Axis to keep the marquee centered on the axis of the optional reference.
7. Select any warp operation to complete the current warp operation or click to complete the Warp feature.