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DGN_MM: Import of Microstation files in DGN format to MiraMon formats
DGN_MM: Import of Microstation files in DGN format to MiraMon formats| Presentation and options | Dialog box of the application |
| Syntax |
The geographical data model implemented in DGN files, without being aGeographical Information System, can be transformed to the MiraMon, althoughin some case only partially.
The DGN format can contain geographical information based on many graphicelements (polylines, arches of circle or ellipse, ellipses, surfaces ofrevolution and others). The majority of these elements are transformed inelementary objects of MiraMon (points, arches and polygons), with ties todatabases if it proceeds; on the other hand, some very specific graphicelements of architecture and engineering, like for example the surfaces orthe objects of revolution in three dimensions, do not turn due to its fewapplication into the SIG. The application offers you some tools to previousobject selection and generalization to apply in these particular cases.
Some transformation options of the elements present in DGN to MiraMon aredescribed below:
The report generated about the content of the DGN file consists of 3parts:
The summary of the file header gives information about if the file is 2Dor 3D (the elements have only coordinated XY or coordinated XYZ), which arethe principal and auxiliary units (see below on the transformationprojection and coordinates options) and the whole number of elements are inthe file. In this point there are considered to be elements both the graphicobjects and some not graphs, as for example internal colour palettes,databases, informations about attached files, etc.
The second part of the report contains the type of elements and thenumber of them presents in each layer of the file. This also informs aboutthe type of element (with the Mirostation original terminology) and, withinparenthesis, the technical code of the element. Consulting the technicalpapers of Microstation you can obtain more information of theseelements.
Finally, the report contains a summary of the number of elements groupedby type.
The DGN file often contains marked elements to eliminate or elementsbeyond the end of the file. These bogey elements can cause problems duringits import. It is possible to request the application, before beginning thereading of the file, to clean all the marked elements to eliminate. Thisfunctionality has the same effects as the option Compress design ofMicrostation. The original DGN files is stored with DG$ extension and thecompressed file is overwrited on the original one. In some cases, if toomany errors are accumulated, the reading of the elements stops automaticallyand it starts a process of compression.
The DGN file contains information about the units of the elementscoordinates (meters, inches, miles, etc.) but not about the cartographicprojection. The user must indicate if the information is in a coordinateslocal system or in a cartographic projection known by MiraMon. In the firstcase it is necessary to indicate if the element coordinates must betransformed according to the DGN principal units or the secondary ones (forexample kilometers the principal ones and meters the secondary ones).Remember that the principal and secondary units appear in the report of thefile. In the case that the user indicates a known cartographic projectionsystem , the conversion factor is calculated automatically between the unitsof the projection and the DGN principal units. For example, if theprojection selected by the user is UTM (and therefore the units of thecoordinated are meters) and the principal units of the DGN file arekilometers, the conversion factor calculated automatically is 0.001. If thisautomatic calculation has no success it is requested the user to indicatesthe conversion factor. Notice that all this information serves to documentcorrectly the metadata of the files and that only it implies, as much, toscale the coordinates. In it is necessary, the user can also indicate scaleand displacement factor in X and Y.
The application transforms all the elements known of all the layersautomatically. To avoid to transform not wished elements there you canindicate some elements selection that are applied before the transformation.Selections can be indicated for:
For example, the user can indicate that wants all the elements of thelayers 4 and 15, which are polylines, of blue or green colour, withcontinuous style and width 2. The operator applied between the differentoptions is always AND and the operator inside each option is OR. If othertypes of selections are needed, they can be carried out on the output filewith Vecselec. The selection of elements of type cell only can get togetherwith the selection of the level where it is; in this case the selections oftype, width, style and color are ignored.
All these options of selection of DGN elements allow the user to realizepartial transformations of the file and to organize the result in differentMiraMon layers.
Due to the fact that the information in DGN format has not typical GISstructure, this application offers some possibilities of transformation, toadapt its format.
It can be requested that the application separates automatically each DGNlevel in different MiraMon layer. This way we will manage to have, forexample, all the elements of the layer 6 of the DGN in only one structuredMiraMon arch line file. The names of the output files, one for each levelwith elements, are created automatically from the name indicated by the userbut with a numerical suffix (for example FICHERO_MM01.ARC, FICHERO_MM02.ARC,etc).If this parameter is not indicated, all the elements of all the layersare transformed automatically in only one MiraMon structured file, of archsand/or points as it corresponds.
In the database associated with the elements transformed to MiraMon, theinformation stored is:
The user can request the application to keep another complementaryinformation for each object, as for example if it is a connectable object,if it has been modified, if it is blocked, if it is solid, etc.
Microstation can created and use cells. The cells are group of simpleobjects that are used as a unit and that are used often as symbols. Forexample, to represent a geodesic vertex, we can use a cell formed by threesimple lines forming a triangle with a solid circle of black color in themiddle. This grouping of simple objects can have a name, for example VERTEX,and we can use it as many times as it is necessary in the drawing. Thisapplication allows you to treat the case of the cells of a suitable form,depending on the case. In some cases it is interesting to transform thecells to its primitive elements, but commonly it is interesting to transformit into a point and to associate the most excellent information in thedatabase.
If it is requested to transform the cells to points with symbology, thereis a MiraMon point structured file (PNT) is automatically generated. In thedatabase associated with these points the information regarding the level,type, colour, style and width, the tie with the database dictionary (in casethese elements have information in external databases), the height of thesymbol and its position in the space (orientation in the axes XYZ), theposition of the point of anchoring in terrain coordinates and the name ofthe symbol is stored. This is the automatical option. If the user wants totransform all the cells into its simple objects, these are transformed withthe individual visualization characteristics, not with the common cellcharacteristics.
The DGN file can contain different internal colour table, or it ispossible to associate an external colour table (with TBL extension). Thisapplication allows you to choose between transform an internal or anexternal colour table (in this case it is necessary to indicate the name ofthe file). If there are more than one internal colour palette in the DGN theapplication only transforms the one marked as active. When a color table istransformed, it is stored directly in MiraMon format (DBF file) and it isautomatically associated to the arch or polygon file, so when it isvisualized by MiraMon it appears with the same colours as with Microstation.In case of polygons, the outline and fill colours are saved in the databaseand used if the creator of the DGN has indicated it.
Texts within DGN files are points with an associated text. There areseveral symbolization options for them; most are automatically transformedduring MiraMon conversion process. However, text font types are oftenspecific to MicroStation, so DGN_MM is unable to find out the Windows'most similar one.
Font ids found during the conversion process are written on the textsymbolization tesaurus getting a default symbolization. User should lateradjust this symbolization manually. The same tesaurus could be linked toseveral layers with the same symbolization schema (f.i. same cartographicalseries); for further details, please read /TAULA_SIMB_TEXT parameterinformation below.
With Microstation it is possible to associate the elements with externaldatabases. In these cases all the necessary information is gathered tosupport the tie with MiraMon. In the principal database of the elements,arches or points, a numerical value is saved in a field called IDUSUARI.This field links with a thesaurus that is automatically created; inside it,the type of database and the key field (MSLINK field) linked with it aresaved for each IDUSUARI. The user must know which is the database and thetable that contains the information that he wants to associate. The builderof the layer must provide this information. The field CODIDGNMM is alsocreated automatically, with the combination of the previous key fields, tofacilitate the connection of this thesaurus with the suitable database.Notice that an element can have more than one link to external databases,and that these can be of different types, for example to a DBF table and toan ORACLE table via ODBC. All this information is stored in the thesaurus ofcodes.
Some elements of Microstation form, by definition, closed surfaces. Theapplication detects automatically these cases and generates a file ofexplicit polygons. If it is necessary, the application keeps informationabout the outlines and fill colour of these polygons and the information ofthe associated databases. In case of having islands inside the polygons,these are correctly treated, such as colours as surface calculation.
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| DGN_MM dialog box |