Autodesk Consulting France is working on a project for the Assemblée Nationale to migrate 164 facility management drawings into an Oracle database. vdPConsulting is involved in the project as sub-contractor because of their extended knowledge of AcClassify.
These drawings are interior maps of buildings, where the offices, meeting rooms, hallways, restrooms, etc. are displayed as closed polylines on a certain layer. Within such a space a block is drawn, in which attributes like for example roomnumbers are stored.
AcClassify identifies these areas and finds the containing blocks & attributes, then these areas are written to the database as polygon objects. The information from the attributes are stored as properties of these polygons. In addition, all other lines, blocks and texts are stored as lines and points to be used as background information in the new drawings. These new drawings will be displayed in a web viewer.
Do you recognize this ?
As AutoCAD user you need a basemap as backdrop behind your new design. The survey department maintains the basemap in dg DIALOG. You have to request them to make an export for you in DXF-format.
They don’t have the time to do this right away, so can your project wait or do you use an older version of a DWG that is maybe not completely up-to-date ?
Or… wat about using AutoCAD Map functionality to connect to the dg DIALOG datase in Oracle yourself ?
Because dg DIALOG and AutoCAD Map both support the Oracle Spatial standards.
Nice story, but how ?
As a preparation one needs to organize the automatic grouping of objects based on dg DIALOG objectcodes.
AutoCAD Map connects to Oracle and uses thematic presentation functionality to setup the correct display settings.
These settings are stored as AutoCAD Map template drawings. Such a template is the start of every new project. In this template you’ll find the connection and styling of the data, not the data itself, this comes live from the database. This is “single survey, multiple use” in reality.
Because of this working method the design in AutoCAD and the actual topography from dg DIALOG stay separated. The AutoCAD user can use all well known object snapping functions, because the backdrop data isn’t just a pretty picture. Also is AutoCAD Map capable to “save as” a complete drawing to share with third parties.
Though nobody exactly knows what the ‘prescription-book’ for the new Large Scale Basemap will look like, there are enough reasons the start already. The Province of Limburg has started to make there thousand basemaps of their provincial roads ‘BGT-ready’.
Besides the BGT-project in Limburg, what has evolved from Pilot into Production fase, I’m involved in a couple of other projects where the BGT is an important component.
In existing geo-information systems, DWG is often used as format for large scale basemaps. For other processes in the organisation DWG’s have to be converted into Shape- or SDF-files. We are currently executing a research how to store and use this data from a central geo-database and we would like the structure to be BGT-ready.
More posts about this topic soon.
I’ve written a couple of posts about the BGT-project which I’m working on lately. A recurrent topic, when speaking about the BGT, is: “where should the border polygon be situated ?”
Frist suggestion is the cadastral border. This is also an authentic registration and a good solution for two municiplalities. I’m involved with a project at one of the provinces and they “slice” through municipalities with their provincial roads, that makes the cadastral border less useful.
Users of the provincial map are among others the departments of road- and greenmanagement. Besides surveying the topography, that is situated in a corridor along the road, the road- and greenobjects are important for these maintenance maps. Sometimes there is more green managed than is owned by the province – imagine a ditch that is mown completely, while the cadastral borderline is in the center of the ditch. Currently many road crossings are tranferred into roundabouts, and therefore the province needs to buy pieces of land from municipalities or private owners. The new cadastral situation will take some time to become established and therefore the cadastral border isn’t up-to-date.
In our project we’ve taken a pragmatic approach: we use the outside topographic lines in the corridor maps to build the polygons. In some cases we have to add supporting-lines to close the polygons. If the BGT border polygon has been defined than we will know which polygons needs to be splitted. The current maintenance and cadastral borders are left out of the proces for now. Also buildings, fences, roadlines that a partly on the map, but outside the provincial maintenance area are left out of polygon creation.
With this approach we can create the object oriented map and use the geometry of road- and greenobjects to connect to maintenance-data.
In the meantime still discussing with the GBKN Foundation, municipalities, waterboards, National Road Administration and the Ministry of Housing, Spatial Planning and the Environment about the BGT border polygon.