Geospatial - GISMicrostation-Bentley

Global Mapper, working with dgn

Reading the dgn format is a standard in most GIS / CAD programs, but several of these (including Manifold GIS and gvSIG) have been left reading the V7 format. AutoCAD and ArcGIS have already done this.

Let's see how it does it Global Mapper:

1.Read dgn V8

Global mapper Interestingly, the files can be in a .tar, .zip or .tgz extension.

Once selected, the program asks which projection they will be assigned. These can be chosen from a wide list, or from a .prg file, or a .txt file that contains it. (It does not recognize the internal projection assigned by Microstation Geographics)

Then you can define to assign the same projection to all selected files. You can also generate a projection to taste and save as .prj to call it at any time. It is also interesting that when reopening a file without projection, it stores the last one assigned ... Ohhh yes manifold Look at these simple features !!!

Global mapperIn recent versions, it reads V8, surpassing programs such as Manifold GIS and gvSIG, with the demand that exists for this format and there being only these two among those generated by Microstation.

The texts come as point objects, that is why they have that point in the lower left node. You cannot edit objects, you can touch and delete or edit vertices, but it is only at the view level.

An annoying aspect of the import is that if the objects are white and the background is the same color, it will appear that they do not exist. To do this, you have to place a background of an unusual color, this is done with "view> backgroud color ..."

2. Export to dgn

Global mapper The export is not bad, it will send what is visible in the catalog of the "control center", which is a way of calling the organization of views. Everything will go in the same projection.

Among the most annoying, the size of the texts. To do this, ask to select a size and you have to try. In the case of shape labels, they are converted into texts at the visible size.

Generates a dgn 3D if the map has elevation data; And then leave the option so that the white objects can be seen black or vice versa according to the background.

It also allows exporting in matrix, very good for files that are too large. This makes separate files go, and among the best, it allows to send the reference grid, which may well be in geographic coordinates (latitude / longitude) or UTM.

The export will have problems with complex objects, as in the case of shapes that have holes, since Microstation up to the V8.5 versions still manages these elements as complex shains or cells.

Global mapper 3. Extra options

It is worth mentioning that among the extra configurations you can define that when importing cells (cells, or blocks) into points; If not, exploit them as vectors.

It is also possible to define that the color number can be assigned as an attribute in the table, which would allow the thematization of this criterion.

In conclusion, moderately acceptable. Even though Global Mapper Does many things more.

Golgi Alvarez

Writer, researcher, specialist in Land Management Models. He has participated in the conceptualization and implementation of models such as: National Property Administration System SINAP in Honduras, Management Model of Joint Municipalities in Honduras, Integrated Cadastre-Registry Management Model in Nicaragua, Territory Administration System SAT in Colombia . Editor of the Geofumadas knowledge blog since 2007 and creator of the AulaGEO Academy that includes more than 100 courses on GIS - CAD - BIM - Digital Twins topics.

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5 Comments

  1. Hello,

    I have a geoserver that when it shows the layer does not do it well, I put style line but it shows like spots. The weird thing is that in the preview view it shows fine. The geoserver I have it in a tomcat and when it shows the layer in the console of the tomcat leaves:
    Possible use of the "Tranverse_Mercator" projection outside its area of ​​validity.
    The latitude is outside the allowed limits.

    Anyone know what it can be ?.

    Thank you very much.

    A greeting.

  2. We contacted the Open Design Alliance, but it does not work with open source projects. Come on, that releasing knowledge does not go far.
    And as for the Bentley thing, we've made the request for those specs several times… and we're still waiting for something to come through.

  3. Thank you for clarifying Alvaro.
    And what options are there with Open Design Alliance ?

    According to this Bentley page, it is possible to have some access to documentation regarding the dgn v8 format.

    http://www.bentley.com/en-US/Products/MicroStation/OpenDGN/

    “We have created a document that describes the native DGN file format used by the V8 generation of products. This file format is sometimes referred to as the “V8 DGN” format. The contents of the V8 DGN Specification document are sufficient to allow a skilled programmer to interpret the data within the V8 DGN file that MicroStation creates and processes.”

  4. Reading DGN or another proprietary format, like the DWG, is not about getting it or not. They are closed formats, without open specifications, and therefore the only way to get a proprietary software to read (and / or write) is to reach an agreement (economic) with the commercial house on duty. From the free software the only thing that can be done is reverse engineering, very expensive and that does not guarantee any good result. In gvSIG we read, for example, DWG 2004, something that has not got any other soft.libre, but the effort invested is very large.
    What should be promoted from all areas is the use of open formats, such as GML, and gradually banish the use of closed formats, changing from year to year, and whose sole objective is to maintain market control.

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