AutoCAD LT - DIST distance changes upon snap

[davideltonhall]

I'm quite new to AutoCAD, trying to measure a distance between two lines with the DIST command.

I specify the 1st point and while moving the mouse to the 2nd point the displayed distance is correct. But as I approach the 2nd point, the instant it snaps to the line midpoint (as desired) it displays a strange distance that is an order of magnitude too high.

I've experimented with different UNITS to not avail.

Here is a high-resolution screen cast clip.

[ The subject line of this post has been edited to include the product name by @handjonathan ]

[pendean]

hard to tell without access to your DWG file: can you share it here?

[davideltonhall]

Attached. 

[pendean · Accepted solution]

Thanks for the file.

Your RED LINE has a Z height

But your intersection does not (I used ID command)

so that's a big deal. seems to match up with your video experience. Much of your content is at many Z elevations aka lots of air in between (see view from the "front" below) so I'm not sure how that works for you in a meaningful way, but hey, I'm no civil engineer either 😉

Your distance from 0,0,0 is noted, could be messing with a few things, maybe not.

[davideltonhall]

You pointed me in the right direction.

Instead of measuring the distance with DIST I drew a second line, then did CTRL+1 to view that line's properties.

Sure enough, this line has a 'Start Z' of 0 and an 'End Z' of 437.

When I manually set the Start/End Z to the same value the 'Length' attribute comes out as expected.

Thank you!!