Warp > Spine Operation > To Warp Geometry Using Spine
  
To Warp Geometry Using Spine
1. Click Warp > to open the Spine tab and to display the marquee for the geometry.
2. Click one of the following buttons to specify how the spine deformation is applied:
◦ —Deformation uses a rectangular marquee. This is the default.
◦ —Deformation uses a cylindrical marquee and is applied in the radial direction.
◦ —Deformation uses a cylindrical marquee and is applied along the direction of the axis.
3. Select one or more curves or edges independently. You can also select more than one curve or edge to create chains. The Hide Original check box on the Reference tab should be cleared. If required, create a custom deformation curve using the Sketch tool. An approximate copy of the curves or edges is created. Changes that you make are made to the copy while the original curves or edges are displayed only for reference.
4. If the curve that you select is shorter than the marquee, select Extend Curve to enable the curve to extend to the marquee faces. Clear Extend Curve to keep the curve as is.
 
* For Radial deformation using Spine, Extend Curve will automatically close an open loop.
5. Click the Marquee tab to customize the marquee for the Spine operation:
◦ For a rectangular marquee, specify the First and Second directions' Start and End values to determine the size of the marquee. The range depends on the Marquee Size type that you selected. For cylindrical marquees specify the RadialStart and End values and the Depth if available.
◦ Marquee Size—Select a method of measurement to set the marquee dimensions.
Alternatively, to adjust the region of deformation, drag the faces of the marquee. For example, if the deformation marquee is in the direction of the x-axis, drag the front, back, top, and bottom faces to adjust the region of deformation. If the deformation marquee is in the direction of the y-axis, drag the left, right, top, and bottom faces of the marquee to adjust the region for deformation. For Radial Axis deformation drag the faces that are parallel to the marquee. For example, if the marquee is in the direction of the x-axis, drag the top and the bottom faces of the marquee to adjust the region for spine deformation.
6. If required, click the Options tab and specify the constraints for Point and Tangent for the curve being deformed as follows:
◦ Point—Specifies the behavior of the group of points that you select when you drag the curve.
▪ Free—Points move freely.
▪ H/V—Points move parallel to the selected face either along the horizontal direction or along the vertical direction only. Alternatively, hold down CTRL + ALT while dragging the curve points to make the points move parallel to the selected face either along the horizontal direction or along the vertical direction only.
▪ Normal—Points move along the normal of the selected face. Alternatively, hold down the ALT key while dragging the curve points to make the points move along the normal of the selected reference plane.
◦ Tangent—Specifies the behavior of tangent when you drag it.
▪ Free—Motion of the tangent is unconstrained.
▪ Length—Locks the current direction of the tangent so that only the length changes. Alternatively, hold down the CTRL and ALT keys simultaneously while dragging the tangent to lock the current direction of the tangent so that only the length changes.
▪ Angle—Locks the current length of the tangent so that only the angle changes. Alternatively, hold down the ALT key while dragging the tangent to lock the current length of the tangent so that only the angle changes.
 
* The Tangent setting does not apply any constraints to the selected tangent, but only affects the behavior of the curve tangent when you drag the tangent using the mouse.
7. Select one or more curve points. Drag the selection set to modify the geometry according to the spine curve.
8. Select any warp operation to complete the current warp operation or click to complete the Warp feature.
 
* The displacement of all the control points in marquee operations during a sculpt operation is considered to have a scale value of 1. Specify a value in the Scale box on the Options tab to displace the control points by the required value. For example, specify 2 in the Scale box to double the displacement of all the control points.