Path

The Path constraint uses 3 groups:

Connection Set | Flags | Bounds | Filter | Pick Prompt
Group(0) | E3DOPGROUP_MAIN E3DOPGROUP_INPUTONLY | 1..1 | <undefined> | <undefined> (constrained input)
Group(1) | E3DOPGROUP_INPUTONLY | 1..1 | nurbs curve list or implicit curve | "curve capable of being used as the constraining curve for a path constraint" (constraining input)
Group(2) | E3DOPGROUP_OUTPUTONLY | 1..1 | <undefined> | <undefined> (constrained output)

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