When will a non-custodial parent's obligation to pay child support be diminished if the custodial parent has interfered with custody or visitation rights?

We held in Moffat v. Moffat (1980) 27 Cal.3d 645, 165 Cal.Rptr. 877, 612 P.2d 967 that, notwithstanding the arguable unfairness from the noncustodial parent's perspective of requiring a noncustodial parent to continue making child support payments where the custodial parent has interfered with court-ordered custody or visitation rights, "in such circumstances the child's need for sustenance must be the paramount consideration." (Id., at p. 651, 165 Cal.Rptr. 877, 612 P.2d 967.) We therefore concluded that deprivation of the noncustodial parent's right to visit his or her child did not diminish that parent's obligation to provide child support. (Ibid.)