Transform your drawing based on a coordinate system to another coordinate system to maintain accuracy as project requirements evolve.
Have you ever received a georeferenced CAD drawing with a coordinate system applied, but it’s not the one you need for your project?
Many users try to simply switch the assigned coordinate system and expect the drawing objects to move automatically. However, this does not convert the geometry. Every coordinate system (also called a Coordinate Reference System / CRS) calculates location differently, meaning each X and Y point corresponds to a specific real-world latitude and longitude. If you only change the coordinate system label, the drawing objects stay in the same place and will end up misplaced on the map.
To convert a drawing correctly, you must transform (reproject) the drawing objects into the new coordinate system.
With Plex-Earth, you can do this with a simple export/import workflow.
Step 1: Check the Current Coordinate System
Go to the Plex-Earth ribbon → Assign Georeference, and check the applied georeference. As soon as we confirm this is not the one you want to work with, proceed to the next step.
Step 2: Export the Drawing Objects to Google Earth (KML/KMZ)
Select the drawing objects to reproject.
Go to the Plex-Earth ribbon → Google Earth Tools panel → Export KML/KMZ. The step-by-step guide on exporting your drawing can be found here: Import or Export KML/KMZ to Google Earth
Step 3: Create a New Drawing and Assign the Target Coordinate System
Create a new blank drawing.
Go to the Plex-Earth ribbon → Assign Georeference → By Coordinate System.
Apply the coordinate system you want to work with
More information can be found here: Choose a Coordinate System.
Step 4: Import the KML/KMZ into the New Drawing
In the new drawing, use Plex-Earth Import KML/KMZ.
Import the file you created in Step 2.
Your objects will now be inserted in the correct location according to the new coordinate system, and your drawing will be properly converted.
FAQs
Can I just change the assigned coordinate system in Plex-Earth to convert my drawing?
No — changing the coordinate system label alone does not move or reproject your drawing objects. Each coordinate system calculates positions differently, so simply reassigning the CS leaves your geometry in the same place and it will appear misplaced on the map. To correctly convert a drawing, you must reproject the geometry using the export/import KML workflow described in this article.
Will my drawing objects be preserved after the conversion?
Yes — the workflow exports your objects to KML/KMZ (which stores them in geographic coordinates), then re-imports them into a new drawing assigned to the target coordinate system. Your geometry is preserved and placed in the correct location for the new coordinate system. Note that object properties such as layer names, colors, and linetypes may need to be reassigned after import, as KML does not carry all CAD attributes.
What if I don't know the correct coordinate system for my project?
You can check with your surveyor if they designed with a specific CS in mind and browse Plex-Earth's full list of coordinate systems. If you're unsure and simply want to import data, apply a Custom Georeference instead.
Is this the same as applying a transformation to my coordinate system?
Not exactly. This article covers a full reprojection — converting your drawing from one coordinate system to a completely different one. If your drawing is already in the right coordinate system but needs a correction or offset applied (e.g., a datum shift or local adjustment), see Apply Transformations to Assigned Coordinate System or Other Applied Georeference instead.
Related Questions
This article explains how to reproject a CAD drawing from one coordinate system to another using Plex-Earth's KML export/import workflow. You may have searched for:
- How to change the coordinate system of my drawing in AutoCAD
- How to reproject or transform my drawing to a different CRS
- I changed the coordinate system but my drawing is in the wrong place
- How to convert a drawing from one projection to another
- How to switch from one coordinate system to another without losing my geometry