Recap Coordinate system shift/scale issue

[Jay.Meszar]

Hello,

I am experiencing issues with bringing in an LAS file to Recap and saving the RCP.  The import works fine, saving works fine, but when it is imported into anything else (Civil 3D or Infraworks), the coordinate system shifts.  I know this because I brought the LAS file into Civil 3D with little effort and created a surface.  Everything looks great.  I then (as a check) imported a pts file that was exported from Recap and the two are WAY off.  So, I brought the rcp file into Infraworks and also brought the surface into Infraworks.  The surface is good (checked rough LAT/LONG against google earth) but the point cloud is roughly in the right location but seems to be scaled 3 to 4 times the surface.  You can see in the attached image that one point cloud is almost the same size as the surface that was created from 4 point clouds....any help you can provide would be great.

[ryan.frenz]

Hi Jay,

This appears to be an issue with units somewhere.  The PTS exported from ReCap will be in meters, so make sure you're attaching it as such in Infraworks.  Similarly, make sure you're attaching the LAS file with proper units to make your surface.  The 3-to-4x scale you see is likely a meters/feet discrepancy (roughly 3.3x).  The tough thing about LAS is that it doesn't 'know' the units, but usually you can specify them on import.  In my experience, most outdoor LAS files are in survey feet.

I'm not familiar enough with CIvil or InfraWorks to give you detailed instructions there, but hopefully this should at least give you a start toward fixing this.

Thank you for using ReCap Pro.

Ryan

[esorensen]

I'm having the same issue. Can someone post a detailed solution to changing the units? Thanks! 

[esorensen]

I have solved this issue successfully, here is the the soultion I have until I receive an Imperial template for ReCap.

I had to specify the coordinate system for the data going in and out of ReCap, for me that was ID83-CF, then I exported the point cloud to the .rcs format. Because Recap is in metric units I had to specify that the data was in the ID83-C projection when I brought it into InfraWorks, this seems to solve the issue.

[sb]

Does anyone know how to solve this problem when importing the point cloud into Revit?

[tarheels09]

We have had a problem with .rcs files shifting coordinates out of Recap. Our surveyor had warned us this was going to happen

because of the conversion from meters to feet in recap. It has to do with  "us feet" and "international feet". This has been a known problem

since this product was released and it has not been fixed ???. We spent weeks working with the Revit help desk on this shifting problem because

they had no idea what was wrong. Also nice to find out after hours and hours and hours of wasted time converting files

that this is the case. The work around from you guys is move the file in revit. Not the way it should be.   Plus letting customers know that the update for recap 2014 is a completely different program than what we recived in our software package would have been really nice.

[esorensen]

You can import the raw .las file into Civil 3D 2014 directly--easiest by using the planning and analysis Workspace, index it firts then attach. I also use Arc GIS and Global Mapper for certain tasks. Some of the applications are easier to use than others. Then I export the point cloud into other formats if I need it, or I can build surfaces from the ground returns. Good luck!

[tarheels09]

No matter what program you import the raw data into, you are still going to get a coordinate shift. Our surveyors have imported their data directly into civil3d and it still moves. I have been told this is the future of surveying. If it is then someone needs to fix this issue. You there Autodesk?

[ryan.frenz]

I'm sorry to hear about these problems.  If you don't mind, a few questions for clarification so I can try to cross-reference the known issue you mention (I can't seem to find it, but I may be misunderstanding your problem).

- What format and units are the files you are importing to ReCap (the standalone app)?

- Are you changing any import settings?

- After import, is the data in the right place in the ReCap viewer?  If not, how is it wrong (i.e. is it a meters/feet issue, or something else)?

- When attaching the RCP or RCS to another Autodesk product (Revit, AutoCAD, etc), do the coordinates change yet again?  If so, by how much?

ReCap will store everything in meters, so nothing should 'shift' unless there is a mismatch between the input units (e.g. in your LAS file) and the display units.  The questions above should help narrow it down for us.

Ryan

[tarheels09]

- las files to recap
- las files from scanner in meters, change to feet in recap
- No, data shifts in recap
- No, Revit imports what it sees, Amazing?
- We spent two working with Revit and Recap help. They have all the files.

[ryan.frenz]

Thanks.  I assume you're wanting to work in US feet?

Note that the units setting in ReCap is for display in the standalone app only - it isn't used by Revit or the other products.  Instead, they will read the ReCap files (in meters) and do their own scaling (based on your unit settings in that application).  So you should be able to display the data in any units that Revit supports.

Ryan

[tarheels09]

Yes US feet, You can check the coordinates in Recap and it has already shifted
the file. Revit and the other programs just read what they see. Like I said before, you guys have all the files.

[ryan.frenz]

OK, thanks for the clarification.  I don't think your files are the problem.  Your data is appearing to shift because ReCap is using the International convention for display.  The display engine can support US feet as well, but it is not enabled in the UI.  I'll put this feature on the development backlog.

Your data should appear correctly in meters (please confirm that).  If so, you should be able to display in US feet in Revit or AutoCAD.

Ryan

[tarheels09]

We are using US feet in Revit. Changing the coordinates in Recap to meters and checking the coordinates, we still get wrong coordinates. I think its the conversion factors from meters to Us feet. Large coordinates mean larger errors. Hope this helps solve this (Where have they been hiding you for the last two weeks?)

[esorensen]

Until Recap is fixed (and the latest release might be?) I do the following and it works every time:  

1. If the raw data is in US feet I specify that it is in feet when I import it to Recap. I typically work with state plane (feet) foordinates.

2. Revit will convert it to meters automatically, for now I just accept this reality, and export my data.

3. Then when I import the data in the next application (InfraWorks) I specify that the data is in state plane (meters).

This works every time for me. Hope this issue is fixed soon though.

[tarheels09]

Thanks, I hope it is fixed soon also. It has been one frustrating, time wasting two weeks. Then we still have to move the scan.

[ryan.frenz]

We can support US feet as a new feature in an upcoming release.  But I'm still a bit concerned that something else may be going on.

@tarheels09: You made a comment that "Changing the coordinates in Recap to meters...we still get wrong coordinates."  If the LAS files are in meters, and ReCap is set to meters, your coordinates should be exactly as expected (no Feet/Meters conversion should even be applied, obviously).  Are you using a state-plane or other geographic transformation?  If so, which one?

Ryan

[tarheels09]

Sorry Ryan, you are correct. The coordinates in Recap are right. When this is fixed and it comes into Revit in the right place, it will solve a lot of problems. Thanks for all your help.

[esorensen]

Thanks Ryan! Every application has its quirks, this will be an awesome quirk to eliminate, it will facitilate easier training to the end users where I work.

Cheers!

Erin

[richiee]

@tarheels09 & @esorensen :

I wanted to let you guys know that last week we released our May hotfix (version 1.3.4.5) which contains support for US Feet. You should see the update appear in your Autodesk Applications Manager.

Please don't hesitate to reach out if you encounter any other issues.