GB2458145A

GB2458145A - Combined CAD and GIS data processing

Info

Publication number: GB2458145A
Application number: GB0804174A
Authority: GB
Inventors: Crispin Hoult
Original assignee: 1SPATIAL GROUP Ltd; 1SPATIAL SCOTLAND Ltd
Current assignee: 1SPATIAL GROUP LIMITED
Priority date: 2008-03-06
Filing date: 2008-03-06
Publication date: 2009-09-09
Also published as: GB0804174D0

Abstract

A method of interfacing to a computer aided design (CAD) system to enable a computer aided design to be combined with geographical information is disclosed. The method comprises inputting data identifying a selected portion of the CAD data for combining with geographical information, wherein the selected portion of the CAD data is defined by geographical coordinates; retrieving geographical information system (GIS) data for the selected portion of the CAD data, the GIS data representing the geographical information; processing the GIS data to convert this into object data representing objects to the CAD system, the object data comprising the geographical information; and further combined processing, in the CAD system, of the CAD data representing the computer aided designs and the object data comprising the geographical information. A CAD system combining CAD and GIS data processing is also disclosed.

Description

Data Processing Systems

FIELD OF THE INVENTION

This invention relates to data processing techniques for combining computer aided design (CAD) data with geographical information system (GIS) data.

BACKGROUND TO THE INVENTION

With the use of geospatial data becoming more widespread, connecting to and accessing GIS data in CAD clients is becoming an issue. In particular there is a need for efficient, high quality, up-to-date mapping data to be provided for CAD users. Although GIS administrators and CAD managers sometimes provide proprietary solutions, these often lack versatility leading to the use of old data, duplication of resources, and ineffective licensing. Further, many organisations cannot afford to implement such proprietary solutions.

A CAD user may often wish to place a CAD design over spatial data. This can be done by exporting the CAD design and importing the design, for example in DXF (drawing exchange format) data into GiS editing software, placing the CAD design drawings using rather approximate positioning. However, this is inaccurate, time-consuming, cumbersome and, in paiticilar has difficulty with the large data files which are often encountered: The file sizes can be so large that implementation on desktop computing systems is impractical.

There therefore exists a need for improved techniques.

SUMMARY OF THE INVENTiON

According to the present invention there is therefore provided a method of interfacing to a computer aided design (CAD) system to enable a computer aided design to be combined with geographical information for further processing, said CAD system being configured to store computer aided design (CAD) data representing said computer aided design, the method comprising: inputting data identifying a selected spatial region of or for said computer aided design for combining with said geographical information, wherein said selected spatial region is defined by geographical coordinates; retrieving geographical information system (GIS) data for said selected spatial region using said geographical coordinates, said GIS data representing said geographical information; processing said GIS data to convert said GIS data into object data representing objects to said CAD system, said object data comprising said geographical information; and further processing said object data using said CAD system; and wherein said further processing comprises combined processing of said CAD data representing said computer aided design and said object data comprising said geographical information.

In embodiments, by selecting the portion of CAD data the (background) mapping effectively loads on demand, which facilitates handling very large data files. Thus, for example, CAD designs with which embodiments of the method may be employed may comprise CAD designs with a physical extent of lOs or lOOs of square metres or more and/or designs comprising multiple entities spread over a geographical area such as a housing estate or airport and/or designs which involve CAD planners/engineers working on sites spread over an entire country or continent. In embodiments the geographical data loads direct from its source, without the need for intermediate data formats or caching, which helps to ensure that the information retrieved is up-to-date and live.

The bandwidth of the data processing is also helped by employing geographical information defined as objects, in preferred embodiments editable objects. Thus embodiments of the method may even operate in substantial real time, for example loading data on demand as a user of the CAD system pans and/or zooms around the CAD design. Preferred embodiments of the method operate with three-dimensional CAD designs but, in principal, the method may also be applied to two-dimensional CAD designs.

Embodiments of the above-described method enable a user of the CAD system to interface directly with spatial data stored in relational databases, files and web based services. Thus authentic and high quality cartography, including accurately and logically placed text and point features, can be displayed in conjunction with the computer-aided design. Thus, for example, the clear display of accurate geospatial data helps lead to simpler and quicker data analysis through visualisation allowing errors to be spotted easily. Any suitable geographical coordinates may be employed in embodiments, for example, National Grid coordinates and/or US State Plane coordinates.

Preferred embodiments of the method enable a user to input data to locate a GIS server from which the GTS data is to be retrieved. This GIS data may be in any of a wide range of "standard" formats including (but not limited to): SHP (shape) file fonnat data, ESRI (environmental systems research institute) data including Personal Geodatabases, Pitney Bowes Mapinlo data, Oracle (Registered Trade Mark) SDO (spatial data object) data, ArcSDE (RTM) server data, SDF (spatial data file) data and other data types more generally vector file format data, raster file format data, spatial relational database data and spatial web services data.

In preferred embodiments of the method the further processing of the combined CAD and GIS data comprises processing this data in a common user session on the CAD system, for example to display in conjunction with one another a portion of the CAD design and a corresponding portion of the geographic information.

In some preferred implementations of the method the processing of the GTS data to convert this into object data employs two software processes, the first to provide an interface to a plurality of different GIS data sources, and a second to provide an interface to the CAD system. In embodiments the first software process provides a stream of data from the GIS data representing coordinates of spatial features such as points lines and the like together with associated information such as text and attributes and the second software process processes this data stream and converts this to object data for the CAD system. In preferred implementations these two software processors communicate via a common shared memory block (which could be considered to operate in the manner of an elastic buffer).

In some preferred implementations of the method the first software process comprises a feature data object (FDO) process (for example, a process from an FDO spatial data abstraction library) and the second software process is configured to intercept data generated by the FDO process and to call an API (application program interlace) of the CAD system so that the objects representing the geographical information arc drawn (displayed) in the context olthat part of the CAD design on which the user is at that time working.

In embodiments of the method the GIS data is processed to select (lata defined by the window of geographical coordinates and a by-product of this process in an FDO-based implementation is that a set of data base -like rows is generated in niemory including data for shape data objects comprising (x, y) pairs of coordinate data. These coordinates are passed to the CAD system using an API to invoke a procedure to create the object specified by the coordinates, and of the type specified for example line, point, area (open or closed) and the like.

Tn preferred implementations the shape objects obtained from the FDO process include attribute data which is used to define one or more layers into which the GIS data is to he iiicorporated in the CAD system. Preferably these one or more layers are exclusively used by the GIS data.

In embodiments of the method the CAD data itself may comprise geographical or map data. 1-lence the CAD design may comprise a geographical design. Thus, embodiments of the method may be employed to combine two different sources of a geographical information, a geographical design and geographical information from another source, which may itself be another CAD system. In this way two different geographical designs may be worked on and combined, for example houses for a housing estate and an environment for the houses.

In some preferred embodiments the method is implemented as a plugin to a computer program implementing the CAD system, for example AutoCAD (RTM), Corel Draw (RIM) or another CAD computer program.

Thus the invention further provides computer program code to implement embodiments of the method. The code may he provided on a carrier such as a disk, for example a CD-or DVD-ROM, or in programmed memory for example as Firmware. Code (and/or data) to implement embodiments of the invention may comprise source, object or executable code in a conventional programming language (interpreted or compiled) such as C, or assembly code, code br setting up or controlling an ASIC (Application Specific Integrated Circuit) or FPGA (Field Programmable Gate Array), or code br a hardware description language such as Vcrilog (Trade Mark) or VHDL (Very high speed integrated circuit 1-lardware Description Language), in preferred embodiments, a program written for the.NET fi-amework. As the skilled person will appreciate such code and/or data may be distributed between a plurality of coupled components in communication with one another.

The invention further provides a computer aided design computer system to implement a method as described above.

Thus in a further aspect the invention provides a computer aided design (CAD) computer system, the system comprising: a user interface; an interface to receive geographical information system (GIS) data from a geographical information system (GIS) server; working memory for storing working data and computer aided design (CAD) data representing a computer-aided design to be combined with geographical information for further processing; program memory storing computer aided design (CAD) computer program code to implement said computer aided design (CAD) system using said user interface; and a processor coupled to said user interface, said interface to receive said GIS data, said working memory and said program memory; and wherein said program memory further stores computer program code to: input data identifying a spatial region of or for said computer aided design for combining with said geographical information, wherein said selected spatial region is defined by geographical coordinates; retrieve from said GTS server geographical information system (GIS) data for said selected spatial region using said geographical coordinates, said GIS data representing said geographical information; process said GIS data to convert said GIS data into object data representing objects to said CAD system, said object data comprising said geographical information; and further process said object data using said CAD computer program code; and wherein said further processing comprises combined processing of said CAD data representing said computer aided design and said object data comprising said geographical information.

In prelelTed embodiments the stored computer program code also includes code to implement software processes as described above, communicating via a data stream at least part of which is temporarily stored using a shared portion of the working memory.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other aspects of the invention will now be further described, by way of example only, with reference to the accompanying figures in which: Figures 1 a and lb show, respectively, a flow diagram of a procedure to implement an interfacing method according to an embodiment of the invention, and a screen shot of a configuration screen for the interface; Figure 2 shows a block diagram of a CAD system configured to implement an embodiment of the invention; and Figures 3a and 3b show, respectively, a simple example of a combination of a computer aided design with GIS data, and an example of a GIS data layer as displayed in a CAD system.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Referring to figure 1 a, an embodiment of a procedure to implement an interface for GIS data begins, at step S 100, by initialising tlîe CAD system and by the user defining the location of a GIS server from which the GIS data is to be obtained. An example screen shot from this procedure is shown in Figure 1 b, illustrating selection of a GTS data provider (in the example an Oracle database called MasterMap (RTM)). As illustrated, the GIS data may have a plurality of different layers (optionally drawn from different locations). For example, in the case of GIS data representing a housing estate one layer may represent houses, another flood planes, a third sites of special scientific interest, and so forth. An administrator control panel for the interface may, as illustrated, enable an administrator to select layers for processing/display.

At step S102 the CAD system loads and displays data for a CAD design, enabling a user to select a portion of the design for combining with GIS data. For example the CAD design may comprise architect designs for houses of a new housing estate and, for example, the user may pan and zoom to one corner of the display before clicking on a "query GIS" button in order to load the GIS data. Alternatively, the GIS data may be streamed in substantially real time from its source depending upon the currently viewed portion of the CAD design. In an embodiment by default the extent of a current display screen is taken as defining the geographical extent of the GIS data to import.

Additionally or alternatively the user may type in a set of geographical coordinates and then bring the selected geographical information into the CAD system prior to constructing a CAD design over the geographical information.

In other implementations the first two steps may be omitted from this procedure. For example they may be performed in a separate process or, say, by another user saving a configuration file.

Thus, at step SI 04, the procedure receives a user request for GIS data and, based on the currently viewed display window or user-defined area, invokes an FDO (feature data object) connector to retrieve the selected GIS data, and at the same time invokes interface code for the CAD system (S 106). As the FDO code reads the selected GIS data (S 108), although it does not explicitly generate coordinate data as an output, as part of the reading process data is streamed from the G1S server into shared memory 206a as rows of data, similar to a database. A row of data will include coordinates and -attributes, more particularly for each shape in the GIS data, for example, line, point, area aiid the like, a set of pairs of brackets (x, y) coordinates together with an identification of the type of shape. This information is intercepted in the shared memory 206a by the interface code (SIlO) which reads this data and invokes corresponding features in the CAD system, for example via an APT (application program interface) to create corresponding objects in layers of the CAD system. For example an area shape may be created by invoking a draw-closed-line type API in AutoCAD (RTM) or by invoking a create polygon function in Corel Draw (RTM), and so forth. In this way, the GIS data is converted into editable shapes in the CAD system.

In preferred embodiments the data in the shared memory 206a includes geometric (or example shape) attribute data as well as geometric (for example shape) object data, and this attribute data is used to define layering of the corresponding shapes in the CAD system. Thus, in embodiments, one or more attribute values of the shape data is mapped to one or more layer values of the CAD data.

At step Si 12 the editable shape data created by the interface procedure is further processed by the CAD system together with the CAD data, for example displaying both together to illustrate discrepancies or errors in either the GIS data or the CAD data. In embodiments of the method the computer aided design may be a geographical design, for example in a case where two different entities collaborate on different aspects of a design each of which extends over a geographical area, such as a housing estate and a local environment for the housing estate. In a similar way the GIS data may be generated by a CAD system, the CAD system being used to create a design which extends over an area of, say, greater than 1 Urn2, 100 m2 or 1000 m2.

Referring now to figure 2, this shows an embodiment of a CAD system 200 configured to implement the above-described method. The CAD system includes a processor 202, non-volatile program memory 204, working memory 206, a display 210, and a user interface 212, for example comprising a keyboard/tablet/mouse or the like. The CAD system 200 also includes a data store 208 of CAD data for a CAD design. The program memory 204 stores CAD prograni code, user interface code operating system code and CAD-GIS interface code to implement the above described method, this latter code comprising Feature Data Object code, for example from a C++ library, and CAD program interface code. In embodiments the CAD-GIS interface code invokes the FDO code using a.Net interface and interfaces with the CAD program code via an API for the CAD program. Data from the FDO processing is captured by the CAD program interface code from a shared portion 206a of the working memory 206. The CAD-GIS interface code may optionally be provided on a carrier, illustratively shown by disc 204a. The CAD system 200 is coupled to a GIS system 220 (which may itself by a CAD system) via a network or local storage files 214 which may be a local or wide area network and/or which may include the Internet. The GIS system 220 as illustrated comprises a GIS server 216 coupled to a GIS data store 218.

Referring now to figure 3, this shows examples of combined CAD-GIS data. in figure 3a a bandstand 300 is shown in its geographical context; in figure 3b a layer of geographical data displayed in a CAD system (AutoCAD (RTM)) is shown. In embodiments of the method we describe a spatial data object comprising a point may be translated into a block or point, optionally employing a symbol library olcommon representations of objects which may he attached at the point (optionally including a rotation angle). Figure 3b illustrates a treatment of text used by embodiments of the method, which places the text in the CAD data using one or more (preferably all) of: anchor-position, alignment, orientation, and height.

As previously described, embodiments of the method provide substantially live, on-demand access to GIS data such as Oracle (RTM) data, in embodiments without using a local cache for the G1S data. This helps reduce connection lag and the need for large local disc storage, and reduces the need for user management to maintain synchronisation of data with a GIS database. Embodiments of the method also facilitate administrator controlled database access to secure data via DBA administered views.

One preferred implementation of the method operates with AutoCAD (RTM), creating native AutoCAD (RTM) entities such as polylines, points, inserts and text; text support may also be provided as labelled points and lines. As previously mentioned, layer support is preferably provided for data visualisation through templates and layer states; this may be extended to block attributes for a spatial attributes. It will also be appreciated that the techniques we described may be employed to display geographical features within many different CAD data formats, for example also including vector data.

We have described an embodiment of the method in which GIS data is incorporated into a CAD system, but it will he understood that once in the CAD system this data may be modified or edited and then written back to the GIS data store (spatial database/dataset).

Thus, in embodiments the method may also be employed to remove the need for a conventional GIS or spatial data editing system, in effect converting the CAD system to a combined CAD-GIS data workstation for editing and/or display of both these data types.

No doubt many other effective alternatives will occur to the skilled person. It will be understood that the invention is not limited to the described embodiments and encompasses modifications apparent to those skilled in the art lying within the spirit and scope of the claims appended hereto.

Claims

CLAIMS: 1. A method of interfacing to a computer aided design (CAD) system to enable a computer aided design to he combined with geographical information for further processing, said CAD system being configured to store computer aided design (CAD) data representing said computer aided design, the method comprising: inputting data identifying a selected spatial region of or for said computer aided design for combining with said geographical information, wherein said selected spatial region is defined by geographical coordinates; retrieving geographical information system (G1S) data for said selected spatial region using said geographical coordinates, said GTS data representing said geographical information; processing said GIS data to convert said GIS data into object data representing objects to said CAD system, said object data comprising said geographical information; and further processing said object data using said CAD system; and wherein said further processing comprises combined processing of said CAD data representing said computer aided design and said object data comprising said geographical information.
2. A method as claimed in claim 1 wherem said data identifying said selected spatial region comprises data identifying a selected portion of said CAD data, and further comprising: inputting data to locate a geographical information system (GIS) server, and selectively retrieving said GIS data from said GIS server using said geographical coordinates.
3. A method as claimed in claim I or 2 wherein said further processing comprises processing of said CAD data representing said computer aided design and said object data comprising said geographical information in a common user session on said CAD system.
4. A method as claimed in claim 3 wherein said further processing in said common user session comprises displaying a portion of said CAD design represented by said CAD data together with a geographically colTcsponding portion of said geographic in formation.
5. A method as claimed in any preceding claim wherein said objects, comprise editable objects and wherein said further processing includes editing one or more of said objects in response to user input.
6. A method as claimed in any preceding claim wherein said inputting of said data identifying said selected portion of said CAD data defined by geographic coordinates comprises inputting said data via a user interface of said CAD system.
7. A method as claimed in any preceding claim wherein said processing of said GIS data to convert said GIS data into said object data uses two software processes, a first software process to provide an interface to a plurality of different GIS data sources and to provide coordinate data for said objects, and a second software process to provide an interface to said CAD system to create said object data for said objects in said CAD system.
8. A method as claimed in claim 7 wherein said first software process and said second software process communicate with one another via a data stream representing said objects.
9. A method as claimed in claim 7 or 8 wherein said first software process comprises a feature data object (FDO) process, and wherein said second software process is configured to intercept data generated as a by-product of said first software process.
10. A method as claimed in claim 7, 8 or 9 wherein said second software process is configured to intercept data generated by said first software process, and to invoke procedures of said CAD system to create said objects in said CAD system.
11. A method as claimed in any preceding claim wherein said processing of said GIS data further coniprises extracting attribute data for said objects from said GIS data, and wherein said object data for said objects in said CAD system includes corresponding attribute or layer identification data derived from said object attribute data from said GIS data.
12. A method as claimed in any preceding claim wherein said computer aided design comprises a geographical design and wherein said CAD data comprises geographical data.
13. A method as claimed in claim 12 wherein said GIS data representing said geographical information is provided by a second CAD system, wherein the method comprises combining two computer aided geographical designs for said further processing.
14. A method as claimed in any preceding claim implemented as a plugin to a computer program implementing said CAD system.
15. A carrier canying computer program code to, when running, implement the method of any preceding claim.
16. A computer aided design computer program configured to implement the method of any one of claims ito 14.
1 7. A computer aided design (CAD) computer system, the system comprising: a user interface; an interface to receive geographical information system (GIS) data from a geographical information system (GIS) server; working memory for storing working data and computer aided design (CAD) data representing a computer-aided design to be combined with geographical information fbr further processing; program memory storing computer aided design (CAD) computer program code to implement said computer aided design (CAD) system using said user interface; and a processor coupled to said user interface, said interface to receive said GIS data, said working memory and said program memory; and wherein said program memory further stores computer program code to: input data identifying a spatial region oor for said computer aided design for combining with said geographical information, wherein said selected spatial region is defined by geographical coordinates; retrieve from said (iTS server geographical information system (GIS) data for said selected spatial region using said geographical coordinates, said GIS data representing said geographical information; process said GIS data to convert said GIS data into object data representing objects to said CAD system, said object data comprising said geographical information; and further process said object data using said CAD computer program code; and wherein said further processing comprises combined processing of said CAD data representing said computer aided design and said object data comprising said geographical information.
18. A computer aided design (CAD) computer system as claimed in claim 17 wherein said computer program code stored in said program memory further comprises code to implement a first software process to provide an interface to a plurality of different GIS data sources, and a second software process to provide said object data to said CAD computer program code, and wherein said first and second software process are configured to communicate via a data stream at least part of which is temporarily stored using a shared portion of said working memory.