Parameters are accessed with C4DAtom::GetParameter()/ C4DAtom::SetParameter(). See Parameter IDs.
Parameter: Color
AMBIENTOCCLUSIONSHADER_GRADIENTParameter: Minimum Ray Length
AMBIENTOCCLUSIONSHADER_MINLENGTHParameter: Maximum Ray Length
AMBIENTOCCLUSIONSHADER_MAXLENGTHParameter: Dispersion
AMBIENTOCCLUSIONSHADER_DISPERSIONParameter: Accuracy
AMBIENTOCCLUSIONSHADER_ACCURACYParameter: Minimum Samples
AMBIENTOCCLUSIONSHADER_MINSAMPLESParameter: Maximum Samples
AMBIENTOCCLUSIONSHADER_MAXSAMPLESParameter: Contrast
AMBIENTOCCLUSIONSHADER_CONTRASTParameter: Use Sky Environment
AMBIENTOCCLUSIONSHADER_ENVIRONMENTParameter: Evaluate Transparency
AMBIENTOCCLUSIONSHADER_TRANSPARENCYParameter: Self Shadowing Only
AMBIENTOCCLUSIONSHADER_SELFTESTParameter: Invert Direction
AMBIENTOCCLUSIONSHADER_REVERSE