The Offset Vectron node will add or subtract from the existing volume (figure 1).
Figure 1: Using a negative Offset value to subtract from the original imported SDF object
Bounds - Determines the bounds of the Vectron geometry.
Input - The Vectron object that the offset will be performed on.
Offset - The amount of offset to apply, negative values will carve away from the edges of the original object.