Join 2 separate lines where they intersect on the Blue axis

wozabee

Hi folks,

today's adventure, a friend asked if we should have a go amateyuer surveying his (highly contoured) land with a makeshift sort of a "dumpey level" with the idea of dreaming up his dream home in sketchup.

well, after painting a bunch of pebbles fluro orange, placing them about in strategic spots, and sighting them from various spots, we have all these lovely vector-looking lines criss-crossing my model of the site that each 'nearly" intersect at where the pebbles should be in 3d space but never quite.
They're usually off by a good few inches, but we'll just take where they intersect on the "blue" axis as the ground location of each sighted pebble (splitting the height difference in the length of a line drawn vertically between the two).

Now, one thing I KNOW sketchup looks like it must be capable of doing - but I've yet to discover how - is running the line tool first along one of these pairs of crossing lines, so it gets the idea, holding Shift (or whatever key/s will do it) then running along the intersecting line above or below until it gives a 'BINGO!" you've got it message for tou to click and make the vertical intersect joining line.

I've needed this before on many models, but usually resort to making a vertical plane on eeach ine, intersecting those, then getting rid of the excess.

So... I'll bet I really feel like a bit of a dummy when told of what the real shortcut is.
Something like I'd always been making fresh water by buying and burning Hydrogen/Oxygen & condensing the steam, then being told "you CAN just collect it from that stream over there"...

ahhh... I see!

jeff hammond

do you mind uploading an example .skp showing the before and desired after? (just real simple.. not the whole model)

it sounds like you just need to use the shift key but you're implying that it's not working out.. i'm probably not picturing the scenario properly so the example would help

wozabee

Hi Jeff,

here's 2 demo files, with, and without, the lines joining on the Blue Axis.
As I said, i had to resort to making a verical plane on each, intersecting the planes to get the Blue axis crossover pont, then deleting the unwanted stuff (which, by that stage is really evertything except for the vertical halfway mark on the new very short intersecting lines).

And yes, I've held "shift", and my mouth, every which way. But I guess the trick is how do you tell Sketchup that you want the inference for joining these two lines to be on the blue axis, and where their vectors intersect it, without it just locking up the line-making tool on the blue axis as soon as you press the up-down arrows.

@unknownuser said:

do you mind uploading an example .skp showing the before and desired after? (just real simple.. not the whole model)

it sounds like you just need to use the shift key but you're implying that it's not working out.. i'm probably not picturing the scenario properly so the example would help

Here's a zip file with a demo of two sighting posts, and 2 sets of nearly intersecting lines. The second shows how they need to join.

wozabee

Also forgot to post a pic of the intersection...

jeff hammond

oh. one of those.
yeah, you can't do it solely with standard sketchup inferencing.

i bet there are quite a few tricks out there but my own go to is similar to yours except i'd use TIG's extrude edge by vector to make the vertical face.. (select a line, extrude it up (or down) but keep it as a group for easy deletion when your done with it.. draw the vertical line then delete the group).

i guess if i had a lot of these on one drawing, i'd consider draping all the criss-cross lines (sandbox tools) onto a flat plane which would show you where the intersections are.