TerraSolid, Bentley Map and CityGML Exports

I have manually digitized 2 - 3 buildings in Microstation using the TerraScan. NOw I wish to take them to the CityGML. Let us start from here.

Excellent, then you can forget my comment about cel, :)

What you have now is basic shape or line  elements for walls roof etc. right.

Now is the tricky part that I haven't either done just for CityGml export purpose within BentleyMap, but if you can , learn Geospatial Administrator, create new or modify an existing XFM schema then it is absolutely the best way to go. See Jeff´s answer. It´s not so difficult when you get the idea of XFM and you have a lot of benefits later on in your projects, when needed to convert/export/import to/from different GIS/CAD/XML formats

But....If you consider open source software instead to do the Citygml conversion, you have an option to do this with ogr2ogr, see links:

www.opengeospatial.org/.../citygml

www.ogr2gui.ca/.../index.php

Then you can use the Bentley Map only export your dgn file with your vectorized buildings to GIS format or save as different Cad format (this can be done with plain microstation) depending what format you chose to work with ogr2ogr

Good luck

//Tom

BTW

You know that if you have the full version of TerraScan and some Lidar data with point classified as Building points, you can automaticly generate the buildings, see example of the workflow on TerraSolid.com

...or you have lidar or pointcload data but no classification you can classify the points manually within Microstation and Point Cloud tools or do the classification through TerraScan with macros or manually either way I recommend you to learn that also.

 See thread:

http://communities.bentley.com/products/geospatial/desktop/f/5924/p/84284/236869.aspx#236869

If this work then it´s easy (easier) to export citygml format.

//Tom

Dear Tom,

That is exactly the same point you mentioned in this thread. Unfortunately, this is not very helpful.

TerraScan not only enables the detection of buildings, but trees and grounds as well, and yes we have the full version of TerraScan here, and TerraModel and TerraPhoto !!!

However, my GIS exposure tells me that features have to be "labelled" as buildings for doing some query etc. Where is that Labelling process? There are many schemas available with CityGML file (the entire zip archive is available for download there). Which schema do I have to use for the export?

The DGN support with GDAL does not exist for DGN v8 and above version. Your OGR2OGR utility is useless here. (see www.gdal.org/.../drv_dgn.html). Safe recommends the purchase of FME ultility which I doubt we would be able to purchase at our end in a short time.

In summary, I would like you to agree that the Bentley Documentation is really crude in the current stage.

Also, I am sorry to say this but Jeff's answer is as Greek and Latin as your last one (for me)!

Shudh

Hi,

In order to export to CityGML file, you need first to create GIS "Features".

Next you need to export to CityGML file using our FME plug-in.

In order to create GIS Features that are compliant with the CityGML schema specification the simplest way is to use the CityGML application template we developed for Bentley Map... You can use either a simple "promote" as mentionned somewhere below or use custom macro we provide to streamline the process when your initial Buildings are expressed as Solids.

So the process is:

1_ get your Building geometries (ideally as solid to warranty that each faces are well snapped together) (This can be done in Vanilla MicroStation)

2_ Load a CityGML schema in Bentley Map

3_ Promote CAD elements into GIS Feature (if you have solids, then the use of the Dedcated macro accelerate the process)

4_ Export to CityGML.

hth

Ben