Parameters are accessed with C4DAtom::GetParameter()/ C4DAtom::SetParameter(). See Parameter IDs.
Parameter: Original Units
CADIMPORT_ORIGINAL_UNITS
Parameter: Geometry
CADIMPORT_GEOMETRY
Parameter: Normals
CADIMPORT_NORMALS
Parameter: UVs
CADIMPORT_UVS
Parameter: Splines
CADIMPORT_SPLINES
Parameter: Instances
CADIMPORT_INSTANCES
Parameter: Materials
CADIMPORT_MATERIALS
Parameter: Display Colors
CADIMPORT_DISPLAY_COLORS
Parameter: Layers
CADIMPORT_LAYERS
Parameter: Visibility
CADIMPORT_VISIBILITY
Parameter: Helper
CADIMPORT_HELPER
Parameter: Hidden Objects
CADIMPORT_LOAD_HIDDEN
Parameter: Source Mesh
CADIMPORT_SOURCE_MESH
Parameter: LOD
CADIMPORT_LOD
Parameter: Scale Based Tessellation
CADIMPORT_SCALEBASEDTESSELATION
Parameter: Scale Range
CADIMPORT_SCALEBASEDTESSELATION_RANGE
Parameter: Linear Interpolation
CADIMPORT_SCALEBASEDTESSELATION_INTERPOLATION
Parameter: Sag . S
CADIMPORT_LOW_MAX_SAG
Parameter: Angle . S
CADIMPORT_LOW_MAX_ANGLE
Parameter: Length . S
CADIMPORT_LOW_MAX_LENGTH
Parameter: Sag . M
CADIMPORT_MEDIUM_MAX_SAG
Parameter: Angle . M
CADIMPORT_MEDIUM_MAX_ANGLE
Parameter: Length . M
CADIMPORT_MEDIUM_MAX_LENGTH
Parameter: Sag . L
CADIMPORT_HIGH_MAX_SAG
Parameter: Angle . L
CADIMPORT_HIGH_MAX_ANGLE
Parameter: Length . L
CADIMPORT_HIGH_MAX_LENGTH
Parameter: Detailing
CADIMPORT_DETAILING
Parameter: Max Sag (mm)
CADIMPORT_MAX_SAG
Parameter: Max Angle
CADIMPORT_MAX_ANGLE
Parameter: Max Length (mm)
CADIMPORT_MAX_LENGTH
Parameter: Combine
CADIMPORT_SEW
Parameter: Swap Y and Z Axes
CADIMPORT_SWAP_YZAXIS
Parameter: Heal
CADIMPORT_HEAL
Parameter: Stitch
CADIMPORT_STITCH_COUNT
Parameter: Optimize Hierarchy
CADIMPORT_OPTIMIZE_HIERARCHY