Parameters are accessed with C4DAtom::GetParameter()/ C4DAtom::SetParameter(). See Parameter IDs.
Parameter: Cast Shadows
COMPOSITINGTAG_CASTSHADOWParameter: Receive Shadows
COMPOSITINGTAG_RECEIVESHADOWParameter: Self Shadowing
COMPOSITINGTAG_SELFSHADOWParameter: Seen by Camera
COMPOSITINGTAG_SEENBYCAMERAParameter: Seen by Rays
COMPOSITINGTAG_SEENBYRAYSParameter: Seen by GI
COMPOSITINGTAG_SEENBYGIParameter: Compositing Background
COMPOSITINGTAG_BACKGROUNDParameter: Compositing Background for HDR Maps
COMPOSITINGTAG_BACKGROUND_GIParameter: Seen by Transparency
COMPOSITINGTAG_SEENBYTRANSPARENCYParameter: Seen by Refraction
COMPOSITINGTAG_SEENBYREFRACTIONParameter: Seen by Reflection
COMPOSITINGTAG_SEENBYREFLECTIONParameter: Seen by AO
COMPOSITINGTAG_SEENBYAOParameter: Force Antialiasing
COMPOSITINGTAG_AAOVERWRITEParameter: Antialiasing Min
COMPOSITINGTAG_AAMINLEVELParameter: Antialiasing Max
COMPOSITINGTAG_AAMAXLEVELParameter: Antialiasing Threshold
COMPOSITINGTAG_AATHRESHOLDParameter: Matte Object
COMPOSITINGTAG_MATTEOBJECTParameter: Matte Color
COMPOSITINGTAG_MATTECOLORParameter: Enable GI Parameters
COMPOSITINGTAG_GIENABLEDParameter: Intensity Ratio
COMPOSITINGTAG_GIINTENSITYParameter: Stochastic Samples Ratio
COMPOSITINGTAG_GIQUALITYParameter: Record Density Ratio
COMPOSITINGTAG_GIDENSITYParameter: Enable Forced QMC Sampling
COMPOSITINGTAG_GIQMCParameter: Enable Transparency Overlook
COMPOSITINGTAG_GITRANSPARENCYParameter: Enable Interpolation Grouping
COMPOSITINGTAG_GIINTERPOLATIONParameter: Mode
COMPOSITINGTAG_EXCLUSION_MODEParameter: Objects
COMPOSITINGTAG_EXCLUSION_LISTParameter: Enable Buffer A
COMPOSITINGTAG_ENABLECHN0Parameter: Object Buffer A
COMPOSITINGTAG_IDCHN0Parameter: Enable Buffer B
COMPOSITINGTAG_ENABLECHN1Parameter: Object Buffer B
COMPOSITINGTAG_IDCHN1Parameter: Enable Buffer C
COMPOSITINGTAG_ENABLECHN2Parameter: Object Buffer C
COMPOSITINGTAG_IDCHN2Parameter: Enable Buffer D
COMPOSITINGTAG_ENABLECHN3Parameter: Object Buffer D
COMPOSITINGTAG_IDCHN3Parameter: Enable Buffer E
COMPOSITINGTAG_ENABLECHN4Parameter: Object Buffer E
COMPOSITINGTAG_IDCHN4Parameter: Enable Buffer F
COMPOSITINGTAG_ENABLECHN5Parameter: Object Buffer F
COMPOSITINGTAG_IDCHN5Parameter: Enable Buffer G
COMPOSITINGTAG_ENABLECHN6Parameter: Object Buffer G
COMPOSITINGTAG_IDCHN6Parameter: Enable Buffer H
COMPOSITINGTAG_ENABLECHN7Parameter: Object Buffer H
COMPOSITINGTAG_IDCHN7Parameter: Enable Buffer I
COMPOSITINGTAG_ENABLECHN8Parameter: Object Buffer I
COMPOSITINGTAG_IDCHN8Parameter: Enable Buffer J
COMPOSITINGTAG_ENABLECHN9Parameter: Object Buffer J
COMPOSITINGTAG_IDCHN9Parameter: Enable Buffer K
COMPOSITINGTAG_ENABLECHN10Parameter: Object Buffer K
COMPOSITINGTAG_IDCHN10Parameter: Enable Buffer L
COMPOSITINGTAG_ENABLECHN11Parameter: Object Buffer L
COMPOSITINGTAG_IDCHN11