rather than the node containing the quad, which shouldn't really make a
difference.
git-svn-id: svn+ssh://src.earth.threerings.net/narya/trunk@3858 542714f4-19e9-0310-aa3c-eee0fc999fb1
used to easily plug in different methods of smoothly varying a value over time.
git-svn-id: svn+ssh://src.earth.threerings.net/narya/trunk@3834 542714f4-19e9-0310-aa3c-eee0fc999fb1