http://www.acm.org/jgt/WilliamsEtAl04.AcknowledgmentsWewouldliketoacknowledgeBrandonManseld,SteveParker,andErikReinhardforprovidingtestcode.JohnMcCorquodalealsoprovidedsomeusefulinformationaboutthespeedofoat-pointmultipliesanddivides.BrianSmits'advocacyforBVHintersectionmethodsandcarewithIEEEpropertiesgaveustheinitialimpetusforthiswork.Theanonymousreviewerofthearticleprovidedveryhelpfulcomments,andpointedoutthatthedividescouldbeperformedonceforafullhierarchy.ThisworkwaspartiallysupportedbyNSFgrant03-06151.References1IEEEStandardsAssociation.IEEEstandardforbinaryoating-pointarithmetic.IEEEReport