Twist

The Twist modifier produces a twist like a screws thread in an objects geometry. You can control the angle of the twist on any of three axes, and set a bias that compresses the threads relative to the pivot point. You can also limit the twist to a section of the geometry.

Twist modifier applied

Reference

Twist Parameters

Twist Area

Angle: Determines the amount of twist around the vertical axis.

Bias: Causes the twist rotation to bunch up at either end of the object. The parameter ranges from -100 to 100. When the parameter is negative, the object twists closer to the gizmo center. When the value is positive, the object twists more away from the gizmo center. When the parameter is 0, the twisting is uniform.

Twist Axis Area

X/Y/Z: Select one of these to specify the axis along which the twist will occur. This is the local axis of the Twist gizmo.

Limits Area

LimitsThe twist will only be applied to vertices that lie in-between the lower and upper limits. The two spinners represent distance along the gizmo's Z axis (Z=0 is at the gizmo's center). When they are equal it is the same as turning off Limits.

Limit Effect: Check this to apply limit constraints to the Twist Modifier.

Upper Limit: Sets the upper limit for vertices that twist will be applied to.

Lower Limit: Sets the lower limit for vertices that twist will be applied to.

How To

To twist an object:

1. Select an object and click Twist on the Modifiers rollout.
2. On the Parameters rollout, set the axis of the twist to X, Y, or Z. This is the axis of the Twist gizmo, not the axis of the selected object. Default=Z.

You can switch between axes at any time, but only one axis setting is carried with the modifier.

3. Set the angle of the twist. Positive values produce a clockwise twist, negative values a counterclockwise twist. An angle of 360 produces a one complete revolution

The object twists to this amount beginning at the lower limit, by default the location of the modifier’s center.

4. Set the bias of the twist. The default is 0, producing a uniform twist along the axis. The possible values are from 100 to -100.

A positive value compresses the twist at the end away from the pivot point, a negative value toward the pivot point.

To limit the twist:

1. Check Limit Effect in the Limits area. Default=unchecked.
2. Set values for the upper and lower limits. These are distances in current units above and below the modifier’s center, which is at zero on the gizmo's Z axis. The upper limit can be zero or positive, the lower limit zero or negative. If the limits are equal, the result is the same as unchecking Limit Effect. Defaults=0.

The twist offset is applied between these limits. The surrounding geometry, while unaffected by the twist itself, is moved to keep the object intact.

3. At sub-object level, you can select and move the modifier’s center.

The limit settings remain on either side of the center as you move it. This lets you relocate the twist area to another part of the object.