Question

DWG BIM to GIS

  • 25 March 2017
  • 7 replies
  • 16 views

Hi,

I want some help in the right direction with converting a DWG BIM 3D file to a DWG 3D CAD/GIS format.

I cannot figure out how to simpoify the 3D-model so that only the outer lines of the 3D model remains

.

I want it to look like the blue line in the attached picture.

Best Regards,

Jonas


7 replies

Hi again,

 

Here is the code that I figured out so far.

 

But the lines is in the middle and not outside and it is very slow! It takes many days if I run with all the object as input...

 

Please help!

 

Best regards,

 

Jonas

 

bim-2-cad-5.fmw 

Heres the FME-code...

 

/Jonas

 

Badge +2
Hi @bigjonas69 ,

 

Is you workspace doing the process up to your expectations?

 

 

Badge +3

Hi @bigjonas69,

If I understand your question correctly, the solution might be much simpler. When you place a combination of a SurfaceFootprintReplacer, a HullAccumulator and a DonutHoleExtractor after the GeometryFilter, you'll get exactly a polygon that represents the blue line in your first screendump.

I have set the HullAccumulator to "Hull Type: Concave )(" and "Alpha Value: 0.01". This will take some time, but delivers the output you desire. Also you should set the Group By to fme_feature_type if you want to distinct between the two DWG layers that are enabled in your workspace.

If you do not want a polygon, but a polyline, you could use a GeometryCoercer to do so.

Userlevel 2
Badge +17

Hi @bigjonas69, I think you can use the Dissolver to merge footprint polygons for each layer. However, depending on the data condition (slight gaps within a tolerance), a preprocess to perform snapping segments could be required.

In addition, after the Dissolver, additional transformers such as Generalizer (Douglas algorithm) and SpikeRemover might be helpful to clean the geometries.

Hi @bigjonas69,

If I understand your question correctly, the solution might be much simpler. When you place a combination of a SurfaceFootprintReplacer, a HullAccumulator and a DonutHoleExtractor after the GeometryFilter, you'll get exactly a polygon that represents the blue line in your first screendump.

I have set the HullAccumulator to "Hull Type: Concave )(" and "Alpha Value: 0.01". This will take some time, but delivers the output you desire. Also you should set the Group By to fme_feature_type if you want to distinct between the two DWG layers that are enabled in your workspace.

If you do not want a polygon, but a polyline, you could use a GeometryCoercer to do so.

It worked after I only took one layer.

 

Group by have also worked.

 

Thanks!

 

Sincerely,

 

Jonas

 

Hi @bigjonas69, I think you can use the Dissolver to merge footprint polygons for each layer. However, depending on the data condition (slight gaps within a tolerance), a preprocess to perform snapping segments could be required.

In addition, after the Dissolver, additional transformers such as Generalizer (Douglas algorithm) and SpikeRemover might be helpful to clean the geometries.

Okay, thank you for the tips and trix...

 

Sincerely,

 

Jonas

 

 

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