Like with modeling, you use a falloff to attenuate the effect any deformer has on a target item and to provide additional control about how deformers influence a mesh.
To add a Spline Falloff to a scene, you must first add a Spline Deformer. The falloff item uses this Deformer and its resulting curve to produce the falloff. The Deformer, itself, does not have to be active for the falloff to function, but the falloff needs the deformer to be present as a container for the Locators. Then, you can use both the Spline Deformer and Spline Falloff together without duplicating the spline.
Once you define a Spline Deformer, you add the Spline Falloff to it by right-clicking the Spline (Full Mesh) layer within the Deformers viewport or the Item List and choosing Add Override > Falloffs > Spline Falloff. Once you create the Spline Falloff, you manually connect the resulting Spline Effector to the Spline Falloff's Spline Effector connector. Doing this, requires familiarity with the Schematic viewport. You create a link by dragging a connector between the Spline Effector's relationship output and to the Spline Effector input of the Spline Falloff. For the falloff to adjust the range of the deformation rather than shift along the length of the spline, set the Spline (Full Mesh) item Interpolation mode to Linear. Once defined, the falloff then properly attenuates the affects of the Spline Deformer.
At this point, select the Spline Effector item and disable it. Then, add an additional Deformer to the Item and link the Spline Falloff output to the resulting Item's Falloff's input to have the falloff attenuate the influence of the new Deformer. The falloff's position relative the the undeformed item determines which parts of the target item Modo affects. See the Schematic viewport topic for more information about adding Items to the viewport and linking the items together.
Name: Displays the current item's name. You may change the name by clicking the current name and typing a new name.
Position XYZ: Indicates the numerical position of the Effector item in XYZ space. Position transforms originate from the Center position.
Rotation XYZ: Indicates the rotation of the Effector item numerically. Rotation transforms originate from the Center position.
Order: Indicates the order that Modo applies rotations to the falloff item. By changing this order, you can sometimes reduce or eliminate gimbal lock.
Scale XYZ: Sets the size of the item's representation in the 3D Viewport numerically. Scale transforms originate from the Center position.
Reset: Resets the selected transform values to (0,0,0) and returns the item to its default state.
Zero: Resets the selected transform property values to 0 but leaves the Center position and the item's position intact.
Add: Adds a Transform item to control an item's position, rotation, or scale. By default, new items do not have any transform items associated with them (although they are visible within the Properties panel). Only add the necessary transforms on an as-needed basis to reduce scene overhead. You can also use this Add function to add a selected set of transforms to the Channel list while keeping the default 0,0,0 values, which is necessary for Referencing. (To override channels, they must exist.)
Enable: Toggles the falloff on or off. When clear, the falloff has no influence on the scene. However, Modo saves disabled layers with the scene and their values are persistent across Modo sessions.
Range: Defines the distance away from the Spline that the falloff influences its target.
Falloff Shape: Controls the rate of attenuation across the falloff with four options.
• Linear - Provides a straight attenuation of the falloff's influence across its total range.
• Ease In - Gives a smooth attenuation with greater influence toward the start of the falloff's range.
• Ease Out - Gives a smooth attenuation with greater influence toward the end of the falloff's range.
• Smooth - Provides a smooth attenuation with a slightly stronger influence in the middle of the falloff's range.
Use Setup Spline: Select when the Spline is both a deformer and a falloff. When selected, Modo uses the Setup Spline shape to compute distances between the vertices and the spline. (The Setup Spline is how it looks in its Setup state.) When you use the Spline as both a deformer and a falloff, Modo determines the falloff on the undeformed vertex positions. Then, the deformer can pull the mesh out the reach of the falloff and cause deformation artifacts. With Use Setup Spline selected, Modo produces a more desirable result.
Axial Falloff: Controls the strength of the falloff along the length of the curve. A value of 0% generates no axial falloff. A value of 100% attenuates the falloff's strength along the curve with the maximum influence at the base of the curve and no influence at its termination point; a value of -100% produces the inverse: no influence at the base and the maximum strength at the terminator. (You can use values of greater than 100% to achieve unusual results.)
Axial Shape: Controls the attenuation amount along the length of the curve when you set Axial Falloff to a value greater than 0%. This duplicates the functionality of the Falloff Shape option, but Modo applies it along the length instead of outward from the Spline Falloff's core.
Use Node Scale: When selected, you can scale the Locator(s) that make up the Bezier Falloff's curve that then scales the Range value. This acts as a multiplier on a per node basis. In the unselected, default state, node scaling has no effect on the falloff's Range.