Parameters are accessed with C4DAtom::GetParameter()/ C4DAtom::SetParameter(). See Parameter IDs.
Parameter: Test Only
GV_RAY_TEST_ONLY
Parameter: Global Coordinates
GV_RAY_GLOBAL
Parameter: Ray Point1
GV_RAY_INPUT_POINT1
Parameter: Ray Point2
GV_RAY_INPUT_POINT2
Parameter: Collision
GV_RAY_OUTPUT
Parameter: Hit Position
GV_RAY_OUTPUT_HITPOS
Parameter: Face Index
GV_RAY_OUTPUT_FACE_INDEX
Parameter: Distance
GV_RAY_OUTPUT_DISTANCE
Parameter: Is Backface
GV_RAY_OUTPUT_BACKFACE