Xref Insertion Points

[joeroscia]

I received an existing conditions drawing from a surveyor which I do a "save-as" and re-name to convert to my standards, very typical for the clients I work for, in AutoCAD LT.  As a check I xrefed in the original surveyor's drawing and it comes in in a different location in space.  When I ID the same point in both drawings they are identical x,y coordinates.  When I open the original file and xref in the converted file the same thing happens.  Why don't these drawings come in directly on top of each other?  I've attached both files; "2021_03_10_Velencia-Base 03-09-2020 CAD.dwg" is the original surveyors file and "21034.dwg" is the file I converted.  Any help would be very appreciated.

[pendean]

Your content in both files are very very very far away from the 0,0,0 point: a little over 3-million units.
That's is a lot for a program that works in units (regardless of inches or mm or whatever).

Your content needs to be closer or at/near 0,0,0.

HTH

[joeroscia]

I never intentionally move an existing conditions survey as they are almost always georeferenced.   I understand what you are saying but don't see how this should make a difference.  The file in which I changed the drafting standards (layers and colors) is an exact copy of the original.

[cadffm]

You are right, the basepoint/origin is not 0,0,0 -> INSBASE

In this case i would move your xref to the right place -7498.40288515,-7220.84484935,0.00000000

or change insbase in the original file (only if you won't send it to another one)

[joeroscia]

CADffm-

I still don't understand why these two files do not align considering one is a direct copy of the other in a location on the face of the Earth.   When I pick a point in the surveyor's file and bring it into Google Earth it drops right on the property.  If I bring in the coordinates you provided I'm way out in the Atlantic Ocean.

[cadffm]

Sorry, FOR ME this is basic-knowledge for everyone how works with blocks or xref.

I try it short and in clear words, but forgive me - english is not my native language.

Every BLOCK and DWG XREF have a basepoint, this basepoint is the grip on References you can see.

The Basepoint of every file is saved in INSBASE variable, for usual it is 0,0,0 WCS (in your file it is not 0,0,0 as you can see by INSBASE<enter>).

So why doesn't match the one file to the other? Rethink of what i wrote: The basepoint is saved in INSBASE variable.

Simple example:

FileA with a Text at wcs 10,10,0 and insbase 2,2,0

as XREF in another file.. and you will see, the Text appears at 8,8,0

because the basepoint of FileA is 2,2,0

from 2,2,0 to 10,10,0 is 8,8,0

You are not alone,

many users thinking that the wcs is important for a file as block or as xref, and wcs0,0,0 is the base-point, but it isn't.

[joeroscia · Accepted solution]

This is interesting!  I changed the INSBASE to 0,0,0 in both drawings and now they do align when xrefed.  Is this an acceptable solution?

[cadffm]

>"I changed the INSBASE to 0,0,0 in both drawings"

Why? You should change it

if you know WHY! And only if you know it haven't an negative impact on another place 😉

>"and now they do align when xrefd."

Sure, but the result would be the same if insbase in YOUR file is set to 111,222,333 😉

Insbase is not important for the current file, it is important if you used this file as Xref or Block, nothing else.

>"Is this an acceptable solution?"

WE DON'T KNOW THAT.

To be able to judge that we have to know
how the original file was used and how your file is used (by the customer).

For example "my FileA" -> FileA with a Text at wcs 10,10,0 and insbase 2,2,0

I send my FileA to you..

How i use my FileA on my side only as Xref, your job is to create a file with <whatever>information at the right position.

You get my FileA, you create a copy "FileB" and replace my Text at 10,10,0 with a rectangle..

back to your question "Is this an acceptable solution?"

You reset Insbase in your FileB to 0,0,0, you did your job an send me this FileB

I take this FileB as Xref and....instead a rectangle at 8,8,0 as expected and where my text From FileA appears,

your rectangle appearing upper on the right in my main file - it appears at 10,10,0

In this case (I set the basepoint a 2,2,0 because i wand and need that setting)

your way is not an acceptable solution 😉

But we all can not say what your customer need and want.

[Pointdump]

Joe,
Here's what I did in both drawings to make 'em line up. Maybe not all are necessary.
BASE >> 0,0,0
SNAPANG >> 0
VIEW >> TOP (cuz I'm a North-is-up kinda guy)
DA must have moved your post. I remember it starting off in the AutoCAD Forum.
Dave