Volume test (Roberts 63)
for wireframe images - "the hidden-line problem"
assumes an infinite eye point (0, 0, -inf)
2-D:Test all edges against all polygons
3-D: Test all edges against all polyhedra
Define polygons/polyhedra as the intersection of positive halfspaces
of planes
hold t constant and it defines a ray
if that ray is in the negative halfspace of any of the planes, that
point is visible
time: O(n2), where n = # edges
preprocessing: none
coherence: takes advantage of edge coherence
scene footprint: total
memory footprint: a polygon and an edge
overdraw: worst possible case! Every edge is checked regardless
of its location
clipping: not done
transparent objects: could be extended to do it
use: no one in their right mind uses this.