Question

Microstation V8 .dgn to .las

  • 15 September 2016
  • 5 replies
  • 18 views

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I am trying to take zero-length type 3 (Line) data from a microstation v8 file to a .las file. I am able to read, but I keep getting the flollowing response in the log:

"DESIGN READER: Failed to read XFM feature store element. Skipping element read GeometryCoercer: Cannot coerce from IFMEPoint to fme_point ... Last line repeated 2498 times ..."

What would be the best way to get these zero-length type 3 lines over to a .las file? Thanks!


5 replies

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Hi,

I would use the chopper to transform it into points.

Userlevel 4
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You don't have a GeometryCoercer in there do you? FME will read a zero-length line from DGN as a point feature anyway, so you don't need to coerce it separately. The message comes up because it is already a point feature!

If that error occurs in the DGN reader itself, then I'd be more worried! Can you view the data correctly in the Data Inspector without that error?

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I tried the chopper, but has similar issues.

When I remove the GeometryCoercer I get the following error from the LAS Writer:

"LAS writer: Failed to obtain point cloud from feature. Only features with point cloud geometry are expected."

So I guess the trick is to get the data into "point cloud geometry" first. If I try the GeometryCoercer to do that, I get the same message as above, except with "point cloud" instead of "point".

We often use the .las format for non-lidar data as it is universally read by most software. I have successfully used FME to created a plain XYZ text file from the points (in 300 .dgn files), but that is not nearly as efficient for reading, so I'll need to convert it to .las anyway. Thankks for the help.

Userlevel 4
Badge +25

I tried the chopper, but has similar issues.

When I remove the GeometryCoercer I get the following error from the LAS Writer:

"LAS writer: Failed to obtain point cloud from feature. Only features with point cloud geometry are expected."

So I guess the trick is to get the data into "point cloud geometry" first. If I try the GeometryCoercer to do that, I get the same message as above, except with "point cloud" instead of "point".

We often use the .las format for non-lidar data as it is universally read by most software. I have successfully used FME to created a plain XYZ text file from the points (in 300 .dgn files), but that is not nearly as efficient for reading, so I'll need to convert it to .las anyway. Thankks for the help.

I think what you need to do is this:

 

1) Add a Reader

 

2) Add a GeometryFilter - just as a precaution - to make sure you are reading points only.

 

3) Connect the GeometryFilter:Points port to an Aggregator transformer to join them into a multi-point geometry

 

4) Then use a GeometryCoercer to convert them to a point cloud.

 

 

In short, the GeometryCoercer won't convert single points to a point cloud, but it will convert a multi-point geometry.

 

 

Hope this helps.

 

 

Mark

 

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Thanks @Mark2AtSafe. That did work, however, the memory requirements are a bit troublesome. For 4 files, with 1.4million points, FME got up to 6+GB of memory usage. I'm assuming it would have continued to grow if I had more files; and I typically would. I'll try outputting the files individually instead of putting them into a single .las files. Thanks!!

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