How to keep the same value after changing drawing unit?

[sukishums]

Hi,

I'm trying to change the drawing unit from feet to meter, after I did it, it was affecting the elevation of the new COGO points I created. For example before changing unit, a point with elevation 17 become elevation 54 after. 

How do I change unit from feet to meter without affect values of old and newly created points?

[Pointdump]

Hi @sukishums,
How are you changing the Drawing Units?
Dave

[ChicagoLooper]

Hi @sukishums 

Can you explain how you determined the distance (or length) is 17ft to begin with? Can you upload a screenshot?

Did you start a drawing from scratch or are you working from an existing drawing?

Is the drawing georeferenced? Most importantly, do you know whether the drawing’s assigned coordinate system uses meters or feet? Or you don’t know?

Are you using a metric or imperial template?

[AllenJessup]

How did you change the units?

[sukishums]

Hi, @Pointdump @AllenJessup @ChicagoLooper 

Thanks for all your reply I should have explained more.

What I'm trying to do here is convert TOPO points in dwg file into a PNEZD text file format, so I can import them into C3D as survey points.

Surveyor sent us a dwg file, I open that file in C3D and it contains TOPO points.

The file should be in Meters but when I open it in C3D it is preset as feet.

However if I open it in Autocad it is fine showing units as Meters.

Back to C3D, without changing anything, it shows Position Z (elevation) of this point is 15.1650, which is the correct value, but in the wrong unit. I would like it to be 15.1650 meters but not 15.1650 feet.

So I change the drawing units from Feet to Meters.

It doesn't affect the existing points on the drawing. It's still 15.1650

Then, I convert this Point into COGO point with the 'Convert Autocad points' button, Easting, Northing and Point elevations all shown in feet now. COGO point elevation is 49.754'.

What's the proper way to convert autocad points into survey points for the use in C3D?

Thank you so much in advance guys.

[Pointdump]

@sukishums,
Thanks for the extra information.
A couple of ways you can go about this. You can use command -DWGUNITS and when you get to "Scale objects in current drawing to reflect change in units?" click "No".
Another way, since it looks like all you have are AutoCAD points, use command DATAEXTRACTION to pull XYZ information into a CSV file. Then you can import into a Metric drawing.
Dave

[hencoop · Accepted solution]

The PNEZD file is unitless.  If the values are correct, just write out the current values and ignore the units.  You will apply the correct units to the new drawing prior to importing the piint file.

[andrewpuller3811]

Per hencoops comments, export it into csv format and import that into a drawing metric. The csv is unitless and the numbers in it can be imported into a drawing in feet of meters and the numbers will be the same.

With regard to your drawing you have changed to meters, the position of the points is correct for meters, but the values are being shown in feet. If you take the Easting of 145477.0341 and multiply by 0.3048 you get your x value of 44341.4

This issue is caused by the drawing being in feet to start so the civil 3d units are set to display in feet.

To verify this, go to the toolspace -> settings tab -> right click on the drawing name at the top -> select Edit Drawing Settings... -> expand the Coordinate node -> Unit will show as feet. 

If you change that to meter it will correct the coordinate display in the properties palette.

Unfortunately, there are many settings that would need to be corrected as well as all the styles in the drawing - they will use feet as the label units.

[rl_jackson]

Or as a simple solution to what @andrewpuller3811 said, start C3D using the Metric shortcut.

[sukishums]

Hi thanks for replying guys, @Pointdump @hencoop @andrewpuller3811 @rl_jackson 

I have tried all of the above methods but I still couldn't get it right.

1) For the first method,

I typed in 'dwgunits' and type in as you said:

Autocad point is now showing the same value, it is still showing in feet and the value has been scaled.

After I convert it to COGO point,

However I can see in drawing setting the unit has been changed to Metre.

[Pointdump]

@sukishums,
Please post your drawing.
Dave

[sukishums · Accepted solution]

@Pointdump @hencoop @andrewpuller3811 @rl_jackson 

2) For the second method, 

I have successfully export all the points to xyz format in .txt file, but I couldn't use import that file back to a new Metre unit drawing, it said 'No point file format match found'.

I followed this link for the instruction:

https://www.thesourcecad.com/data-extraction-autocad/

I typed in 'DATAEXTRACTION',

I export only the autocad points:

And only with the parameter of Position X, Y and Z:

I unchecked 'show count colomn' and 'show name column' so the sheet only contains the information I need.

I exported it into a txt file:

I opened the txt file and it looks like this:

I fixed it up into an xyz comma delimited file format using Word, now it looks like this:

I open a new C3D drawing with Metre as unit, I clicked on 'Import Points', I chose 'ENZ (comma delimited)', Add file, 

But it said 'no point file format match found'.

[sukishums]

@Pointdump @hencoop @andrewpuller3811 @rl_jackson 

3) The third method,

 Toolspace -> settings tab -> right click on the drawing name at the top -> select Edit Drawing Settings... -> expand the Coordinate node -> Change unit from 'feet' to 'metre'. 

It was in 'foot',

I changed it to 'Meter'

It's still the same value and unitless for my Autocad point,

I convert Autocad point to COGO points, Easting and Northing keeps the value and unit is being changed to meter! (YAYYY), but Point Elevation is still in feet...

Like you said, I am not confident in myself chaging all the units manually. I'm still very new to C3D I wanna make sure my file is correct to start off with otherwise I won't be able to fix it later on with more stuff in it..

[Pointdump]

@sukishums,
Looks like you're really close on this one. Please post your text file. Most likely C3D doesn't like the format. Also, it looks like the first row of your text file has just spaces and needs to be deleted.
Dave

[sukishums]

@Pointdump @hencoop @andrewpuller3811 @rl_jackson @AllenJessup 

I have attached my original dwg file and the points data extraction txt file here, I would appreciate it a lot if you can help me have a crack at it, I don't want what else I can do now. My purpose is to extract the TOPO points from this file from Surveyor into a txt file, so I can put the txt file inside my survey folder, and import it back into C3D as survey points. Million thanks in advance. 

[Pointdump]

@sukishums,
For whatever reason, Civil 3D didn't like that text file. I pasted it into Excel and re-saved it in CSV format. Then it worked.
CSV attached.
Dave

[Pointdump · Accepted solution]

@sukishums,
Another way, use MAPEXPORT to shapefile, then MAPIMPORT into a Metric Drawing.
Dave

[Pointdump]

@sukishums,
There's a problem with using command -DWGUNITS. Even though it will show units as converted to Metric, all the styles are still FEET.
Dave

[ChicagoLooper]

@sukishums 

Where is this?

Perth?

[sukishums]

@Pointdump 

Thank you so much Dave, you are a legend. Both exporting to a csv file and the 'Mapexport' methods work!

Since I would like to underlay it as survey points I reckon exporting to a csv file is a better solution.

It worked when I used the excel file you sent me, but when I tried to redo the whole process my excel file didn't work..

Instead of exporting to txt file, I use 'dataextraction' and export it into csv file this time, which looks exactly the same as your excel file when I opened and read them in excel. However, when I click 'import points from file', my excel file didnt work with the error 'No point file format match found', like what happened to my previous txt file... What's your trick in doing it? Thanks!! Attached are mine and your excel file.