Reference: Matthias Hopf, Michael Luttenberger, and Thomas Ertl. Hierarchical splatting of scattered 4d data. IEEE Computer Graphics and Applications, 24(04):64–72, 2004. Suggested BibTeX entry: @article{g4hopf,     author = {Matthias Hopf and Michael Luttenberger and Thomas Ertl},     journal = {IEEE Computer Graphics and Applications},     number = {04},     pages = {64--72},     title = {Hierarchical Splatting of Scattered 4D Data},     volume = {24},     year = {2004} }

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