Select an editable patch, editable mesh, or editable spline, or an object that has an Edit Mesh, Edit Patch, or Edit Spline modifier applied to it. > Modify panel > Choose a sub-object level. > Soft Selection rollout
The Soft Selection controls make a sub-object selection behave as if surrounded by a "magnetic field." Unselected sub-objects within the field are drawn along smoothly while you transform the sub-object selection, the effect diminishing with distance. If a sub-object selection is passed up the modifier stack, and Use Soft Selection is on, the results of modifiers such as Bend and XForm that deform the object are affected by the Soft Selection parameter values.
The controls in this dialog let you modify Soft Selection parameters. All sub-object levels share the same Soft Selection parameter values. Soft Selection is available for mesh, poly, patch, and spline objects.
Interface
Note: The keyboard shortcuts listed here require that the Keyboard Shortcut Override Toggle be turned on.
Use Soft Selection: Affects the action of Move, Rotate, and Scale functions within editable object or edit modifier, and the action of deformation modifiers applied to the object if they are operating on a sub-object selection. When on, gmax applies a spline curve deformation to the unselected sub-objects surrounding the selection that you transform. To take effect, this check box must be on before moving the selection.
Edge Distance: This spinner setting limits the region affected by the number of edges between the selection and the affected vertices. The affected region is measured in terms of "edge-distance" space, along the surface, rather than real space.
Affect Backfacing: When on, deselected sub-objects whose normals (or, in the case of vertices and edges, the normals of faces to which they're attached) are facing in the opposite direction to the average normal of the selected sub-objects, are affected by the soft selection influence. Turn off Affect Backfacing when you want to pull faces of a thin object, such as a thin box, but don't want to affect faces on the other side of the object.
Note: Affect Backfacing is not available when editing splines.
Falloff: Distance in current units from the center to the edge of a sphere defining the affected region. Use higher falloff settings to achieve more gradual slopes, depending on the scale of your geometry. Default=20.
Note: At the Vertex sub-object level, the region specified by the Falloff setting is depicted graphically in the viewports as a vertex-color gradient from the Sub-selection color (normally red) to the Vertex Ticks color (normally blue). In addition, this gradient is updated in real time as you change the Falloff setting.
Pinch: Raises and lowers the top point of the curve along the vertical axis. Sets the relative "pointedness" of the region. When negative, a crater is produced instead of a point. At a setting of 0, Pinch produces a smooth transition across this axis. Default=0.
Bubble: Expands and contracts the curve along the vertical axis. Sets the relative "fullness" of the region. Limited by Pinch, which sets a fixed starting point for Bubble. A setting of 0 for Pinch and 1.0 for Bubble produces a maximum smooth bulge. Negative values for Bubble move the bottom of the curve below the surface, creating a "valley" around the base of the region. Default=0.
Soft Selection Curve: Graphically displays how Soft Selection will work. You can experiment with a curve setting, undo it, and try another setting with the same selection.