Importing KMZ Files with British National Grid

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05-07-2015 03:50 PM
PaulBushnell
New Contributor

Hi,

We are building a City Engine model at the moment. As part of this model we wish to import KMZ files with 3D models. We can do this however it appears that the buildings imported are slightly misplaced. I think the issue is that to get them accurately positioned we need to specify the transformation required (in this case Petroleum). Is there a way that this can be specified?

Thanks,

Paul

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7 Replies
RichardDaniels
Regular Contributor

I'm not an expert on this, but hope this helps.

In CityEngine the default coordinate system is CityEngine CS (Meters). When working with georeferenced data you need to set a valid coordinate system set. There are three methods:

  1. Setting a Coordinate System when GeoRef data is added to the scene
  2. Setting a CS when creating a new scene
  3. Change the scene CS in the preferences

When a CS is changed no projection on the fly is done -you are only defining the projection CS for the display. Secondly, geographic CS are not supported AND CityEngine does not support Datum-Transformations. Thus you need to project/reproject your data to a common CS prior to importing into CityEngine.

If you have a datum issue it looks like you need to fix it prior to loading into CityEngine

More information can be found at : http://cehelp.esri.com/help/index.jsp?topic=/com.procedural.cityengine.help/html/manual/georef/scs.h...

Rich

SepheFox
Frequent Contributor

Hi Paul, you might also get your question out to a better audience by posting it in the CityEngine​ subgroup. The Esri Technical Support Group that you're posting in has this description: "This group is to discuss anything Technical Support related. Please feel free to contribute topics, questions, suggestions, complaints, concerns, feedback (positive, negative, constructive) etc. We are eager to hear from our customers so do not hesitate to jump in and get involved. We will also use this group as a platform to share ongoing Support initiatives and projects related to all aspects of Esri Technical Support." I don't think that's what you're looking for.

PaulBushnell
New Contributor

Thanks for that. Is there a way to move it so I don't end up cross posting?

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SepheFox
Frequent Contributor

Yes, if you click the title of your question so you are viewing the actual thread, and not just looking at it in your inbox, there will be a list of actions on the right, and one of them is move. If you start to type CityEngine, it should pop up.

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PaulBushnell
New Contributor

Yes that helps. Not sure how to fix my issue though as the City Engine Coordinate system is British National Grid and the KMZ file seems to be using Long/Lat (WGS84?). I don't know whether I can set a KMZ to work in British National Grid or whether I have to "lie" about its position to get the correct end result.

I was also hoping that I could just transform items and move them by a fixed amount using a rule after importing as a fix. As far as I can see its not possible to move models imported from KMZ files?

Thanks,

Paul

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RichardDaniels
Regular Contributor

Have you considered importing the model as a multipatch feature class into ArcGIS then use the standard project and transformation commands to British Grid? You could then export the result for use in SketchUp.

http://resources.arcgis.com/en/help/main/10.1/index.html#//00120000004w000000

PaulBushnell
New Contributor

This looks interesting. I have been trying to adjust the transformation error but have struggled. The solution  you suggest may be an option.

Thanks,

Paul

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