after 3 weeks of perserverance, i am victorious!<br>
<br>
the biggest problem i was having was with the v.clean portion to tie
together the connections with the streets. I used GRASS 6.0.2.<br>
<br>
1) i took buildings (points) and used v.distance to the streets (lines) to create connectors (lines)<br>
2) added category values to connectors, (otherwise v.patch would put them on layer ZERO.<br>
3) used v.patch to patch buildings, connectors, and streets together.<br>
4) ran v.clean - this was the biggest problem. I was expecting
the connectors to break the line where it "touches" it. it would
not break the line. it seems that the connectors would only snap
to nearby nodes or vertexes (cant recall if it did snap to
verticies). so i had to go through 208 points and verify that the
line had a node where the connector was meeting the road. i used
the split tool in QGIS editing the GRASS vectors for each one.<br>
5) ran v.clean again to snap to the manually created nodes.<br>
6) ran v.net.steiner.<br>
<br>
depending on how long it takes on one's machine to compute the steiner
tree, i highly recommend verifying all points manually that they are
snapped to streets. using QGIS i was able to do this relatively
quickly, by looking for red X's that indicated no connection.<br>
<br>
i had to strip down the streets because 28K of them and 208 buildings
took 8 days till i bailed. so i cleaned out roads that i knew it
would not route along (mostly dead ends). after doing this, it
ran with about 9K street lines, and took about 2 days. the
biggest hangup was v.clean not breaking lines where connectors
met. i assumed it was doing this but learned the hard way it did
not.<br>
<br>
one solution i forsee is to use v.split in 6.1, which can add
(unnecessary) verticies every X distance. I believe this would
help the connectors find vertex points to snap too. if it doesnt
snap to vertexes, then it may not help.<br>
<br>
if i can help anyone with this process feel free to ask!<br>
<br>
Great work from the GRASS developers on this one. A network engineer/planner is reviewing the results and is impressed<br>