I first heard about them at Siggraph 2001. This paper https://dl.acm.org/doi/10.1145/383259.383266 https://dl.acm.org/doi/10.1145/383259.383266 by an acquaintan

I first heard about them at Siggraph 2001. This paper https://dl.acm.org/doi/10.1145/383259.383266 https://dl.acm.org/doi/10.1145/383259.383266 by an acquaintance described a way of fitting RBFs to very large point clouds. The trick was to use Fast Multipole Methods, which are a bit like treecodes for n-body problems: https://en.wikipedia.org/wiki/Barnes%E2%80%93Hut_simulation https://en.wikipedia.org/wiki/Barnes%E2%80%93Hut_simulation Fitting an RBF naively involves inverting a matrix as big as the number of points, but the FMM techniques use approximation to make the task practical. JP Lewis has some course notes which explain the basics of RBF techniques well: http://scribblethink.org/Courses/ScatteredInterpolation/scatteredinterpcoursenotes.pdf http://scribblethink.org/Courses/ScatteredInterpolation/scat... For a slightly more technical account, try Sage Shaw's excellent contribution to this Wikipedia page: https://en.wikipedia.org/wiki/Radial_basis_function_interpolation https://en.wikipedia.org/wiki/Radial_basis_function_interpol...