Parameters are accessed with C4DAtom::GetParameter()/ C4DAtom::SetParameter(). See Parameter IDs.
Parameter: Lifetime Map
FP_GEOMETRYMAPS_ATTRIBUTEMAPS_LIFETIME_EXPECTATION_MAPParameter: Speed Map
FP_GEOMETRYMAPS_ATTRIBUTEMAPS_VELOCITY_SPEED_MAPParameter: Direction Map
FP_GEOMETRYMAPS_ATTRIBUTEMAPS_VELOCITY_DIRECTION_MAPParameter: Mix
FP_GEOMETRYMAPS_ATTRIBUTEMAPS_VELOCITY_DIRECTION_MIXParameter: Forward Map
FP_GEOMETRYMAPS_ATTRIBUTEMAPS_ALIGNMENT_FORWARD_MAPParameter: Mix
FP_GEOMETRYMAPS_ATTRIBUTEMAPS_ALIGNMENT_FORWARD_MIXParameter: Angular Speed Map
FP_GEOMETRYMAPS_ATTRIBUTEMAPS_ANGULARVELOCITY_SPINSPEED_MAPParameter: Spin Vector Map
FP_GEOMETRYMAPS_ATTRIBUTEMAPS_ANGULARVELOCITY_SPINVECTOR_MAPParameter: Mix
FP_GEOMETRYMAPS_ATTRIBUTEMAPS_ANGULARVELOCITY_SPINVECTOR_MIXParameter: Color Map
FP_GEOMETRYMAPS_ATTRIBUTEMAPS_COLOR_MAPParameter: Mix
FP_GEOMETRYMAPS_ATTRIBUTEMAPS_COLOR_MIXParameter: Radius Map
FP_GEOMETRYMAPS_ATTRIBUTEMAPS_RADIUS_MAP