@inproceedings{Hall:1995:NPS,
optnote = {},
optaddress = {},
optorganization = {},
author = {Peter M. Hall},
optkey = {},
optannote = {},
optseries = {},
editor = {V{\'{a}}clav Skala},
optpublisher = {},
localfile = {papers/Hall.1995.NPS.pdf},
optmonth = {},
citeseer = {http://citeseer.ist.psu.edu/context/2025672/0},
optcrossref = {},
booktitle = {{P}roceedings of {WSCG'95} (Pilze{\v{n}}, feb 1995)},
optabstract = {},
optstatus = {url},
optvolume = {},
optnumber = {},
abstract = {Visualization applications often need to display objects that are
both three dimensional and coloured. The objects may be
represented either by surfaces or by volumes. The motivation
behind such displays is to demonstrate two or more independent
variables at once. So one variable may determine object shape and
anotehr variable may determine the distribution of colour. A
lighting model is needed to provide cues for visual shape
recognition. Conventional lighting models provide these cues by
altering colour. Hence a conflict arises when this approach is
adopted because the total color variation is made up of two
components that are perceptually indistinguishable. There are
variations that show the distribution of a variable, and global
variations caused by the lighting model. It might be said that a
side effect of the light model is to distort the information
represented by colour. This paper offers a solution to this
problem be replacing the conventional lighting model with a
structured lighting model of the kind used in machine vision
context. The proposed solution simulates the shadow of a regular,
planar grid on the surface of an object. Improved shape cues can
be obtained by using a grid that is sensitive to lighting
conditions, this generates a cross-hatch shading effect. The
notion of a planar grid easily generalises to three dimensions,
where it can be used not only with surfaces, but also with
volumes. The benefit of the method is that colour is effected only
locally, and in well defined places; the remaining colour is
readily identifable and faithfully represents underlying data. In
addition, the method in either of its forms is simple to
incorporate into existing renderers. The method is demonstrated
with results obtained from a computation fluid dynamics
application. Both coloured iso-surfaces and coloured volumes are
shown.},
title = {{N}on-{P}hotorealistic {S}hape {C}ues for {V}isualization},
year = {1995},
pages = {113--122},
}
|