Line Perpendicular not working

[LucasHicks]

I've got one of those drawings.  Where you use the line perpendicular from a point that's supposed to be 3 foot and it goes 851.41.  If you use the line from angle it chooses your backsight and you have to try it a couple of times to get it to work.  Same if you use the transparent commands, nope they don't work.  Also after it finally works the snaps turn off, which is super great.

Any one know how to fix this in a drawing.  Tried audit, didn't help.

Thanks

[wfberry]

??

1.  What version are you using?

2.  From what point to what line?

Bill

[LucasHicks]

2019

There is a dummy red arc off to the side on the left as a test.  Can't draw a use the draw a line perpendicular or tangent from a point that is 3 foot long.  Or draw in any dummy arc or line, doesn't matter.

[rl_jackson]

If you set your OSNAPZ = 1, and draw a line does it work as expected?

[LucasHicks]

Nope.  Tried to draw a perpendicular line from the end of an arc 3 feet.  It went 815.74 feet.  Tried 1 foot, went 815.73 feet.

I will say if I start a new drawing with the template it works as expected.  Something gets corrupted in the file that makes some of the tools useless.  Draw by angle as well and the transparent draw by angle.

[Anonymous]

is this an issue of linework at varied elevations?

[LucasHicks]

Nope.  Arc had the same start and end elevations.

[Anonymous]

i've duplicated your behavior in 2018... very odd....

[rl_jackson]

The drawing has the ELEVATION set to 815.73 so this is now the new plane for all lines. I believe this is your culprit and should fix the issue by setting this to 0

[jmayo-EE]

Bingo Rick and Tim.

Perpendicular in AutoCAD is really a 3d normal line. It will use the Elevation & OsnapZ sys variable settings and any z value snapped to if OSnapZ is set to 0. 

[jmayo-EE]

Oops, Tim's not here. 

[LucasHicks]

So my elevation has to be 0?  I tried setting the elevation to 850, created the arc, and couldn't get the line to draw 3 feet.  Osnapz on 0 or 1.

[rl_jackson]

ELEVATION is a command type it in the command line and set it to 0

[LucasHicks · Accepted solution]

Yes I did that.  If it's set to 0 the command works, if it's set to 850 (osnapz 0 or 1) the command doesn't.  Sometimes my elevation isn't set to 0 for various reasons.

I've got a fix anyway.  Just another bug... I mean feature.

[rl_jackson]

I don't think that's the intent of that variable, you should probably use featurelines, 3dpolylines or survey figures if you need something at a specific elevation. If  your set OSNAPZ it will either read the elevation of the line or figure or read 0 base on the value of OSNAPZ.

I think here what is happening is the transparent tools are angle, bearing etc.... are designed to work with that setting being 0, any other setting would give it a slope. And technically while Civil 3D is a vertical product of Autocad and some AutoCAD commands don't work as there expected too, ELEVATION is a AUTOCAD command not a C3D command. So I don't think this is a "bug" its just something that is not compatible with C3D because C3D has other ways of handling elevation.

[jmayo-EE]

This is not a bug and the two system variables work together.

When osnapz is set to 0 you get the z value of the object you snap to.

When set to 1 you get the z value from the elevation command.

Osnapz does not have any effect if you click in open space. Here the default elevation is from the Elevation system variable.

[jmayo-EE]

https://knowledge.autodesk.com/support/autocad/learn-explore/caas/CloudHelp/cloudhelp/2021/ENU/AutoC...

[LucasHicks]

I'm not calling the osnapz a bug.  I know how that works.  If you have to have the elevation be 0 and the object on elevation of 0 then the tool should not let you choose that element, and explain why (pop up, help, something).  Otherwise a user wastes a crap load of time wondering why a tool isn't working correctly.