Full text (gzip-compressed postscript)
We describe the first known algorithm for efficiently maintaining a
Binary Space Partition (BSP) for n continuously moving segments in
the plane. Under reasonable assumptions on the motion, we show that
the total number of times the BSP changes is O(n2), and that we can
update the BSP in
expected time per change. We also
consider the problem of constructing a BSP for n triangles in
three-dimensional Euclidean space. We present a randomized algorithm
that constructs a BSP of expected size O(n2) in
expected time. We also describe a deterministic algorithm that
constructs a BSP of size
and height
in
time, where k is the number of
intersection points between the edges of the projections of the
triangles onto the xy-plane.