Comments on 'Spacetime ray tracing for animation' by A.S. Glassner

The commenter observes that the impression given by the author of the above-mention paper (ibid., vol.8, no.2, p.60-70, Mar. 1988) that modeling space and time using 4-D recursive division is a novel idea is inaccurate and cites four references to back his statement. He otherwise regards the article as valuable.<
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