Comments, with reply, on ´Display of surfaces from volume data´ by M. Levoy

The commenter clarifies some of the terminology used by M. Levoy (see ibid., vol.8, no.3, p.29-37, May 1988) and puts it into historical perspective with other terminology in use in medical imaging today. He takes exception to Levoy´s use of the term ´volume rendering´. He also discusses his prior use of the term ´gradient shading´ and suggests that it be renamed ´distant gradient shading´ to distinguish it from a similar technique, which is ´density gradient shading´. The author defends his usage, pointing out that it is unfortunate but common for two related scientific disciplines (in this case, image processing and computer graphics) to apply differing and even incompatible definitions to the same term.<>