Parameters are accessed with C4DAtom::GetParameter()/ C4DAtom::SetParameter(). See Parameter IDs.
Parameter: Weight
FALLOFF_STRENGTH
Parameter: Size
FALLOFF_SIZE
Parameter: Scale
FALLOFF_SCALE
Parameter: Offset
FALLOFF_SHAPE_OFFSET
Parameter: Orientation
FALLOFF_SHAPE_AXIS
Parameter: Slice
FALLOFF_SHAPE_SLICE
Parameter: Radius
FALLOFF_SHAPE_TORUS_RADIUS
Parameter: Spherical Falloff
FALLOFF_FUNCTION_SPHERICAL
Parameter: Outer Radius
FALLOFF_FUNCTION_RADIUS
Parameter: Falloff
FALLOFF_FALLOFF
Parameter: Falloff Function
FALLOFF_FUNCTION
Parameter: Clamped
FALLOFF_CLAMPED
Parameter: Spline
FALLOFF_SPLINE
Parameter: Spline Animation Speed
FALLOFF_ANIM_SPEED