KR101546705B1 - Method for visualizing building-inside bim data by bim data process terminal - Google Patents

Abstract

The present invention relates to a method for visualizing BIM data in a building by a BIM data processing terminal. The BIM data processing terminal device according to the present invention receives various BIM data from a BIM server for visualizing building data based on building information modeling (BIM) in a 3D GIS platform. The BIM data processing terminal device includes a data receiving unit which receives the BIM data of a building, an inner object extracting unit, an outer object extracting unit, an LOD generating unit which generates LOD data, a storage unit which stores the DIM data, and a control unit. The present invention efficiently and quickly visualizes GIS.

Description

TECHNICAL FIELD [0001] The present invention relates to a method for visualizing a BIM data in a building of a BIM data processing terminal,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a service for processing BIM (Building Information Modeling) data, and more particularly, to a terminal device for processing large-capacity BIM data and a method for visualizing BIM data in a building of the terminal device.

BIM (Building Information Modeling) refers to the process of modeling a facility in a multi-dimensional virtual space such as planning, design, engineering (structure, facility, electricity, etc.), construction, further maintenance and disposal. In particular, it enables the design and construction of low-cost buildings with cutting-edge design and environment-friendly energy, which is a recent issue, and is a similar concept to the multi-dimensional virtual design construction (VDC). In recent years, the application of BIM has been widely used in civil and plant fields in Europe and the US because it covers all construction environments as well as construction environments.

The building of the BIM (Building Information Modeling) means the entire life cycle of the target building - design, construction, operation and management, and the information means all information included in the entire life cycle of the target building , Modeling refers to an integrated tool and platform that produces, manages, and publishes all information contained in the entire life cycle.

BIM can digitize buildings to produce numerical data, and can display 3D display effects. Data of a length connecting a start point and an end point of a line other than a simple line and a surface operation is generated and the area is data based on the closed surface. By combining the data of length and area, volume data can be obtained.

BIM expresses each property of building objects such as walls, slabs, windows, doors, roofs, stairs, etc., and recognizes each other's relations and immediately reflects the building elements to the building design. Regardless of whether the building to be designed is regular or unstructured, the data generated when building the building is integrated and managed at all levels through compatibility and sharing of each project and each process.

A geographic information system (GIS) is a computer system that collects and makes available the hardware, software, and geographic data of a computer that is designed to collect, store, update, coordinate, analyze and represent all types of geographically referential information .

GIS is a system for storing, extracting, managing, and managing information by linking geographical information that represents a spatial location for various earth surface information references and non-graphic attribute information that explains and complements its form and function with graphical and database management functions. It is an information system related technology to analyze, and it is a comprehensive analysis means that expresses the spatial relation of map by adding characteristic (attribute) information of the geographical information. Geographic data occupying spatial position and related attribute data are integrated and processed. GIS can be widely used in land information management, facility management, transportation, urban planning and management, environment, weather forecasting, agriculture, disaster and disaster, education and population prediction.

From the point of view of the purpose of use, GIS can be divided into Facility Management (FM) system and decision support system for planning support, Land Information System (LIS) (UIS: urban information system).

Recently, an integrated data model that integrates BIM (IFC) data in the construction field and GIS data in the field of spatial information is required for combining and interoperating BIM and GIS, and such studies are underway.

As the demand of 3D building model worldwide increases and the utilization field using 3D building model becomes various, the importance of platform that can serve spatial information of urban model unit by using 3D building model and terrain information Has been highlighted. In addition, since the urban model is composed of numerous buildings, a quick and efficient visualization method of the three-dimensional model is becoming an important factor. Particularly, when screen display is performed on a large-capacity three-dimensional object using a device having limited performance such as a mobile device, smooth operation due to limitation of rendering performance is impossible. In order to solve such a problem, it is essential that a technique for reducing data through a detailed step (LOD) model construction for a three-dimensional real-world model is essential.

Levels of Detail (LOD) are the level of detail in modeling information, which is one of the things that must be negotiated when performing BIM. If the configuration of the LOD model is not clear, it can be confusing to model construction information among stakeholders.

The basic idea of the detail step (LOD) is to use a more compact representation if an object is small or does not contribute to the rendered image. For example, a detailed three-dimensional object model of approximately 10,000 triangles is used when the observer is close to the object. If an observer moves away from an object, simply using a simplified model of about 100 triangles can be seen to be nearly identical to the original model because of the distance. With this method, a considerable speed increase can be expected due to the light weight of the data.

In recent 6 to 7 years, studies on how to construct LOD data by automatically weighting 3D building model in GIS field have been actively studied. Particularly, studies related to LOD generation have been focused on soft polygonal mesh (topography) or regular prismatic three-dimensional building model. However, studies on automatic weight-reduction technology for three- , And further research and development are necessary.

With the advent of Google Earth, the three-dimensional GIS, which has become a global issue, takes the form of connecting individual objects such as terrain and buildings into a series of successive triangles. Each successive triangle is called a mesh, and a three-dimensional object based on the mesh is defined as a mesh model.

The fineness of the mesh model depends on the size of the individual triangles constituting the three-dimensional object. In order to describe a more detailed shape, the size of the triangle becomes smaller and the quantity becomes larger. However, since weight reduction and LOD construction are essential to realize fast and efficient visualization of a 3D building model in the form of a polygon mesh used in a GIS (for example, a 3D GIS platform), visualization of a large number of large- For this reason, it is necessary to construct a data structure suitable for lightweight and structured BIM data.

In order to develop various application fields through interoperability of BIM data and GIS data, efficient and fast 3D visualization is essential. Especially, in order to consider utilization through Web service, A suitable visualization algorithm (rendering process) is a must.

In order to quickly and efficiently visualize the 3D building model of polygon meshes used in GIS (eg 3D GIS platform), it is necessary to study the weight reduction of BIM data and LOD data, And to develop a BIM data processing system that can quickly and effectively visualize a large amount of BIM data through a 3D GIS platform.

The BIM data processing system that renders the BIM data to render large-scale BIM data in the building on the 3D GIS platform is still in its infancy, and concrete and realistic efforts to implement the system and terminal devices need.

It is an object of the present invention to provide a BIM data processing system for visualizing inside objects of a building that efficiently constructs lightweight and structured data and quickly performs rendering in order to visualize large-capacity BIM data in a building on a 3D GIS platform.

Additional features and advantages of the invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the invention. The objectives and other advantages of the present invention will be realized and attained by the structure particularly pointed out in the claims, as well as the following description and the annexed drawings.

The present invention contemplates a BIM data processing system that quickly and effectively visualizes a large-capacity BIM data according to a view point of a 3D GIS platform, a visualization algorithm suitable for weight reduction of BIM data, and an LOD configuration, Dimensional objects (eg, buildings, bridges, urban facilities, etc.) used in BIM-based 3D GIS platforms can be quickly and efficiently visualized.

The present invention relates to a method and apparatus for interoperating between a BIM and a GIS, that is, for visualizing large-capacity BIM data on a three-dimensional GIS platform, a BIM data is stored in a service data structure capable of fast rendering processing, Structured BIM data can be rendered efficiently.

The BIM data processing system according to the present invention can visualize and render large-capacity BIM data in a building on a 3D GIS platform, and a considerable speed improvement of the 3D GIS platform can be expected.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an exemplary view showing a configuration of a BIM data processing system according to the present invention; FIG.
2 is a block diagram of a BIM data processing terminal apparatus according to the present invention;
3 is a diagram showing a data structure of BIM data and a service model recorded in the storage unit of the present invention.
4 is a flow diagram of a method for configuring LOD data for BIM data visualization in a GIS platform in accordance with the present invention.
5 is an exemplary view showing the shape of a three-dimensional mesh model;
6 is a view illustrating a lightening procedure of a polygon mesh type among building objects.
FIG. 7 is an exemplary view illustrating a procedure for weight reduction and LOD data generation for a chair object. FIG.
8 is a flowchart of a BIM data service model generation process according to the present invention.
FIG. 9 is a detailed flowchart illustrating a procedure for visualizing an inside of a building according to the present invention; FIG.
10 is a flowchart illustrating a screen update procedure according to a reference list and block preparation according to the present invention.

In order to achieve the above object, a BIM data processing terminal apparatus according to the present invention includes BIM data receiving various BIM data from a BIM server for visualizing building data based on BIM (Building Information Modeling) in a 3D GIS platform, In the processing terminal apparatus,

An interior object extraction unit for extracting a building interior object from the input BIM data, a sheath object extraction unit for extracting a building exterior object from the input BIM data, An LOD generator for weighting the input BIM data and generating LOD data for each step; a storage unit for storing various BIM data extracted and generated for visualizing an object in a building; And determines whether or not there is a transparent object that can see the outside of the building inside the visible area of the view point, selects the node to be displayed as the view point visible area, determines the step of the LOD data And a controller.

Preferably, the control unit determines whether the viewpoint is inside or outside the building, and when the viewpoint enters the building, the interior objects of the building are divided into nodes included in the visible region of the current viewpoint ), Checks whether or not a node reference list for the node is stored in the storage unit, loads the corresponding node reference list, and displays a transparent object in the visible area of the view point Determining whether a building enclosure object is visible through a transparent object if it is present and determining that the enclosure object of the building is a node included in a visible region of the viewpoint when the enclosure object of the building is visible, Determining an LOD stage for expressing an outdoor building by calculating a distance between outdoor buildings visible through the object, Preparing a block of data on the phase of the outdoor building LOD looks through the transparent object, and the nodes in-domain is characterized by performing a refresh.

Preferably, in order to prepare the block data and update the screen,

The method comprising the steps of: checking whether a skin reference list related to a building external object of the determined node is stored in the storage unit, loading a corresponding skin reference list, loading block data from the storage unit, Block data, and updates the display screen when the mapping process for all references is completed.

In order to achieve the above object, a BIM data visualization method in a building according to the present invention is a BIM data visualization method of a BIM data processing system for visualizing building data based on BIM (Building Information Modeling) in a 3D GIS platform As a result,

Determining whether a viewpoint is inside or outside a building; and determining, when the viewpoint enters the building, determining internal objects of the building as nodes included in a visible region of the current viewpoint Checking whether or not a node reference list for the node is stored in the storage unit and loading the corresponding node reference list; displaying a transparent object in the visible region of the viewpoint, Determining whether a building envelope object is visible through a transparent object if it is present and determining if the envelope object of the building is visible as a node included in the visible region of the view point; , Between the viewpoints and the outdoor buildings visible through the windows in the visible area, and the LOD To prepare the process of determining the block data concerning the LOD step of outdoor buildings visible through the windows, and the nodes in the determined viewing area that comprises the step of performing a screen update.

Preferably, the step of performing the screen update includes the steps of: checking whether a skin reference list related to a building skin object of the determined node is stored in the storage unit and loading a corresponding skin reference list; Mapping the node reference and the skin reference to the block data, and updating the display screen when the mapping process for all references is completed.

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

Brief Description of the Drawings Fig. 1 is a diagram illustrating a configuration of a BIM data processing system according to the present invention.

1, the BIM data processing system according to the present invention includes a BIM data processing terminal 100 for visualizing large-capacity BIM data on a three-dimensional GIS platform, various BIM-based 3D objects (e.g., And a BIM server 200 that stores IFC data (BIM data) of stored objects (e.g., buildings, bridges, city facilities, etc.) to the BIM data processing terminal 100 side .

The BIM data processing terminal 100 efficiently stores the structured BIM data by storing the BIM data in a service data structure capable of fast rendering processing.

2 is a block diagram of a BIM data processing terminal apparatus according to the present invention.

2, the BIM data processing terminal apparatus 100 according to the present invention includes a data receiving unit 10, a data selecting unit 20, a data converting unit 30, a controller 40, An envelope object extracting unit 60, an LOD generating unit 70, and a storage unit 80. [0033] FIG.

The data receiving unit 10 may be configured to receive a BIM-based 3D object (e.g., a building, a bridge, a city facility, or the like) from a 3D GIS platform (e.g., Google Earth, V- (BIM data) of the objects (e.g., buildings, bridges, city facilities, etc.) from the BIM server 200 in order to display the IFC data (e.g., World Wind). .

The data sorting unit 20 divides the data storage format of the objects constituting the geometry information of the IFC data received from the BIM server 200 into a parametric shape or a polygon mesh shape, Data is selected.

The data converting unit 30 converts the parametric data among the received BIM data into a polygon mesh. Further, the geometry information of the received BIM data is converted into a polygon mesh form, and the attribute information of the BIM data is grouped in units of objects.

The building inner object extraction unit 50 extracts each object in the building from the received BIM data. In other words, when the camera's viewpoint is inside the building, it extracts the building endorphic objects exposed in the camera and the nodes in the building (eg, building accessories). The building interior object extraction unit 50 refers to the polygon mesh data, that is, the mesh models, and extracts the building accessories (interior objects of the building).

The LOD generation unit 70 includes a first LOD generation unit 74 and a second LOD generation unit 78. The LOD generation unit 70 reduces the input BIM data and generates stepwise LOD data.

The LOD data for the outside of the building is composed of N + 1 stages (for example, LOD 0 to LOD N), and the LOD data for the inside of the building (for example, LOD 0 to LOD M) The data consists of MN steps (eg LOD N + 1 to LOD M).

The first LOD generation unit 74 generates stepwise LOD data (e.g., LOD N + 1 to LOD M) for building internal structures (objects) extracted by the building internal object extraction unit 50 (Generated).

The second LOD generation unit 78 constructs (generates) LOD data (for example, LOD 0 to LOD N) for building exterior for each building on the building exterior objects extracted by the exterior object extraction unit 50 )do.

The control unit 40 controls the respective components (e.g., the data receiving unit 10, the data selecting unit 20, the data converting unit 30, the building inner object extracting unit 50, the sheath object extracting unit 60, The storage unit 80), and controls the operation of the data processing terminal 100. In particular, the control unit 40 determines whether the view point is inside or outside the building.

In addition, the control unit 40 checks whether there is a transparent object (e.g., a window) or an open space that can see the outside (e.g., outside) within the view area of the view point. It then extracts building envelope objects that are exposed through transparent objects (eg, windows) or through open-ended open spaces. At this time, the control unit 40 directly reads out the view extracted by the skin object extracting unit 60, that is, the building skin object. The control unit 40 first reads necessary data such as a node reference list and a skin reference list from the cache memory 80 and writes the extracted data into the cache memories 80, And requests loading of the corresponding data (for example, a node reference list, a skin reference list, etc.) to the BIM server 200 when it is not stored in the cache memory.

The spatial data linking model stores data received from the BIM server 200 in the cache memory 80 since the data capacity thereof is not so small and the BIM server 200 does not request the data when the data is needed again The data stored in the cache memory is reused. Also, it is easy to manage resources by unloading the resources allocated to the object data out of the visible region of the camera.

The rendering process is to send the geographical information of the camera to the BIM server 200 immediately after the camera operation and to receive the list of buildings existing in the visible area of the camera, It is suitable for performance.

In addition, the control unit 40 determines whether a current view point (view point) is inside the boundary (for example, inside the building) or outside the boundary (for example, outside the building) . If the viewpoint is within the boundary (for example, inside the building), first, the node to be displayed is selected and the level of the LOD data is determined.

The control unit 40 divides the objects to be visualized on an octree basis and assigns an index thereto. The control unit 40 transmits the index information and the result data of the data conversion unit 30 and the LOD generation unit 70 to a header, an object index, a spatial index, , Geometry data, and property data in a data format consisting of five components.

The shell object extraction unit 60 extracts the building shell object from the received BIM data. The enclosure object extracting unit 60 refers to the BIM data, calculates a bounding box, sets a plurality of points outside the bounding box as photographing points, and displays the images (taken) And extracts the skin object by inspecting each pixel of the extracted 2D image in order.

The storage unit 80 stores LOD data (for example, LOD 0 to LOD M) generated by the first LOD generation unit 74 and the second LOD generation unit 78. Also, when the BIM data is converted into a format applicable to the 3D GIS platform, the converted internal structures (objects) and building exterior objects are stored, and the converted data and the structure of the format are stored. Hereinafter, the storage unit 80 according to the present invention includes a cache memory.

3 is a diagram illustrating a data structure of BIM data and a service model recorded in the storage unit of the present invention.

As shown in FIG. 3, the storage unit 80 according to the present invention is stored according to a BIM data service model, and each model (e.g., a building name) includes seven files and one folder.

The seven files of each model (eg, building name) are: Header, Ref_Skin1 to Ref_Skin [N], Ref_bone, Footprint, SpatialStructure, blocks [1] to blocks [M], blocksBone , And the folder includes inLOD [N + 1] to inLOD [M].

The header includes information about the LOD 0 stage, which is the simplest structure among LOD data for building exterior use. The LOD 0 step is composed of simple data such as a rectangular parallelepiped which can be expressed by a bounding box, and the second LOD generator 78 does not separately generate LOD 0 level data.

Ref_Skin1 to Ref_Skin [N] are files storing block reference information of objects serving as building envelopes for each building exterior LOD (e.g., LOD 0 to LOD N).

The Ref_bone is a file that stores block reference information of objects to be always displayed regardless of spatial indexing when rendering the interior of the building.

The footprint is a file that stores extended footprint information of the building. Used to determine if there is a camera inside or outside the building.

The spatial structure is a file that stores spatial structure information of a building.

The blocks [1] to blocks [M], blocksBone are the files storing the original geometry information of objects in the building by each LOD / bone.

The inLOD [N + 1] to inLOD [M] are folders for storing spatial indexing information for each of the building internal LOD data (for example, LOD N + 1 to LOD M).

4 is a flowchart illustrating a method of configuring LOD data for visualizing BIM data in a GIS platform according to the present invention.

As shown in FIG. 4, the BIM data visualization method on the GIS platform according to the present invention includes a step (S10) of receiving BIM data of a corresponding object (e.g., a building, a bridge, a city facility, etc.) A step S30 of converting the data of the parametric type into the polygon mesh form of the input data, a step of selecting the data of the polygon mesh type at step S20, A step S50 of extracting a building envelope object from the input BIM data, a step S60 of composing LOD data of the extracted building envelope object, And storing the LOD data (S70).

Each step of the method of visualizing the BIM data will be described in more detail as follows.

In order to allow a BIM-based three-dimensional object (e.g., a building, a bridge, an urban facility, etc.) to be represented on a three-dimensional GIS platform, the system 100 (data receiving unit 10) (BIM data) of a building (eg, a building, a bridge, an urban facility, etc.). (S10)

When the input of the IFC data (BIM data) is completed, it is determined whether the data storage format of the objects constituting the geometry information of the IFC data is a parametric shape or a polygon mesh shape, do. (S20) Then, the parametric data is converted into polygon mesh data. (S30)

In the present invention, it is necessary to convert the parametric data, that is, parametric based objects, into polygon mesh type data for display (visualization) on the screen, And the LOD data configuration.

The objects of the building in which the geometry information of the IFC data is stored in the form of a polygon mesh are composed of a myriad of vertices as shown in FIG. 5 as an appendage of a building having a complex shape such as a desk or a chair . Each triangular shape shown in FIG. 5 is referred to as a mesh, and a three-dimensional object constructed based on the mesh is referred to as a mesh model. 5 is an exemplary view showing the shape of a three-dimensional mesh model.

As shown in FIG. 5, the mesh model describes only the shape information of the surface of the three-dimensional object, and the inside of the mesh model represents an unfilled shape. The detail of the mesh model depends on the size of the individual triangles constituting the three-dimensional object. In order to describe a more detailed shape, the size of the triangle becomes smaller and the quantity becomes larger.

Generally, mesh-based three-dimensional GIS data has different types of detailed storage formats. However, there are basically three kinds of vertex list, face list, and UV list Item, and is usually stored in binary form.

The vertex list stores sequentially the three-dimensional coordinates of all the points constituting the three-dimensional object along with the point ID.

The face list defines an individual triangular plane composed of three vertices and is composed of only a point ID included in a vertex list.

The UV list specifies a position of a texture in a texture image to be applied to each face. The UV list includes a point ID of a vertex constituting a face, And 1: 1, respectively. If you apply a separate file type texture to each face, you do not have to save the UV list separately, but you can specify the file name directly, Use a single texture file.

Unlike mesh-based GIS data, IFC data represented by the standard format of BIM is parameter-based. In other words, in order to represent a rectangular parallelepiped such as a wall, GIS data directly stores three-dimensional coordinates of all the edges constituting the rectangular parallelepiped and the triangular plane thereof, whereas the BIM data indicates that three end points of the center line (Geometry information), the thickness of this line, and the height of the wall surface (attribute information). Therefore, unlike GIS data, BIM data is characterized in that it is required to calculate its shape every time based on the stored parameters in order to display the three-dimensional shape of the object on the screen.

In order to visualize the parametric based object (BIM data) on the screen, it is necessary to convert the data into polygon mesh type data, which is used to lighten the building envelope object and to construct the LOD data.

When the above conversion process S30 is completed, the system 100 (LOD generation unit 70) selects LOD data (e.g., LOD N + 1) of the polygon mesh data selected in step S20 and converted in step S30 To LOD M). (S40)

As described above, among the objects constituting the building, the objects stored in the form of the polygon mesh are composed of numerous vertices as an appendage of buildings having complex shapes such as desks and chairs. A method of reducing the weight of the object model and constructing the LOD data is as shown in FIG. 6 is a view illustrating a lightening process of a polygon mesh shape among building objects.

For example, if a predetermined light weighting algorithm is applied to a chair (an object in the form of a polygon mesh) that is one of the attachments of a building, stepwise LOD data (e.g., LOD N + 1 to LOD M) And the visualization performance of the 3D GIS platform can be improved. FIG. 7 is a diagram illustrating an example of a weighting and LOD data generation procedure for a chair object.

Then, as shown in FIG. 7, when the object lightening and the LOD data configuration procedure S40 are all completed, the system 100 extracts the building interior object and building exterior object from the input BIM data. (S50)

When the object extraction process (S50) of the building is completed, the system 100 (LOD generation unit 70) extracts the LOD data of the extracted building objects (e.g., internal objects & LOD M). (S60)

The system 100 and the control unit 40 store the LOD data configured in the above procedures (e.g., S40 and S60) in the storage unit 80 as shown in FIG. (S70)

8 is a flowchart of a BIM data service model generation process according to the present invention.

As shown in FIG. 8, the controller 40 first receives an index list of the building from the BIM server 200, and checks whether a header file for the designated building is stored in the cache memory. (S110 to S120)

If the header file is in the cache memory, the control unit 40 loads the header file from the cache memory, and the LOD generation unit 70 reduces the weight of the BIM data of the designated building and generates LOD data for each step. (S130)

If the header file is not in the cache memory, the control unit 40 requests the BIM server 200 to load the header file from the BIM server 200 and instructs the LOD generation unit 70 to send the LOD Data is generated. (S140)

The above procedure is performed for all the buildings on the index list (S150)

Then, the control unit 40 determines whether the view point is inside or outside the building (S160). If it is determined that the view point is inside the building, Extracts the building endothelium objects contained in the area and the nodes in the building (for example, building accessories), and determines the LOD data of the appropriate stage. (S170)

If it is determined in step S160 that the viewpoint is located outside the building, the controller 40 determines whether the enclosure object of the building is a node included in the visible region of the viewpoint, And determines an LOD step regarding the building envelope object. (S200)

A check is made to see if the skin reference list related to the building shell object of the determined node is stored in the cache memory and if the skin reference list is in the cache memory, the list is loaded from the cache memory. (S305, S310)

If the skin reference list does not exist in the cache memory, the BIM server 200 is requested to download all related skin reference lists. (S320)

The above steps S305 to S320 are performed for all building envelope related nodes included in the visible region of the view point. When the above steps S305 to S320 are completed (S330), the control unit 40 Prepare corresponding block data (for example, blocks [1] to blocks [M]). (S340)

Then, this block mapping process is performed on all the skin references to prepare a three-dimensional object creation and drawing (S350). After completion of the block mapping process, the display screen is updated. (S360 to S370)

If it is determined in step S160 that the viewpoint is located inside the building, the controller 40 determines whether the building endothelium objects included in the visible region of the viewpoint and the in- (Eg, building appendages, etc.), and determines the LOD data for the appropriate stage.

FIG. 9 is a detailed flowchart illustrating an internal visualization procedure according to the present invention.

As shown in FIG. 9, when the viewpoint is determined to be inside the building, the controller 40 adjusts the indoor moving speed of the viewpoint according to the mouse operation (movement) of the user. (S171) At a view point over the entire city or several tens of buildings, the moving speed of the viewpoint due to the mouse movement is greatly different from the moving speed of the viewpoint inside the building.

Accordingly, when the view point is located inside the boundary of the outside of the building (for example, inside the building), that is, when the view point enters inside the building, the control unit 40 calculates the difference So that the indoor moving speed of the view point according to the mouse operation is appropriately adjusted.

In addition, when the view point enters the inside of the building, the control unit 40 defines the interior objects of the building as an octree node included in the visible region of the current view point, and displays the LOD Step is determined. (S172) At this time, the determined LOD level will be one of LOD N + 1 to LOD M.

Then, the control unit 40 checks whether the reference list for the determined node, i.e., the node reference list, is stored in the cache memory. (S173). If the node reference list is in the cache memory, the node reference list is loaded from the cache memory. (S174)

If the node reference list does not exist in the cache memory, the BIM server 200 is requested to download all related node reference lists. (S175)

When the above steps S173 to S175 are completed (S176), the control unit 40 determines whether or not the visible region of the viewpoint Check if there is a transparent object (eg a window) or open space in which you can see outdoors. (S177)

The control unit 40 recognizes whether there is a transparent object (e.g., a window) or an open space that can see the outside of the building and displays the object (e.g., a building Envelope object) is visible. (S178). If an enclosure object of a building is visible through a window or an open space, the enclosure object of these buildings is determined as a node included in the visible region of the viewpoint. (S179)

Then, the LOD level is determined for the outdoor buildings that are visible through the windows or open spaces inside the building. (S180) At this time, the determined LOD level will be one of LOD 0 to LOD N. The controller 40 determines the LOD level for expressing the outdoor buildings by calculating the distance between the current view point and the outdoor buildings visible through the window in the visible area.

As described above, when the LOD stage to represent the nodes and the outdoor buildings included in the visible region of the view point is determined (S179 to S180), the controller 40 displays the reference list and the block preparation screen After the update procedure S300 is performed to load the reference list of the outdoor buildings of the node determined in the step S179, the building internal objects included in the visible region of the current view point (Such as an image, an object, an attachment, etc.).

10 is a flowchart illustrating a screen update procedure according to the reference list and block preparation according to the present invention.

As shown in FIG. 10, the controller 40 first checks whether a reference list, that is, a skin reference list, for the outdoor buildings of the node determined in step S179 is stored in the cache memory. (S305). If the skin reference list is in the cache memory, the corresponding skin reference list is loaded from the cache memory. (S310)

If the skin reference list does not exist in the cache memory, the BIM server 200 is requested to download all related skin reference lists. (S320)

The above steps S305 to S320 are performed for all building envelope related nodes included in the visible region of the view point. When the above steps S305 to S320 are completed (S330), the control unit 40 Prepare corresponding block data (for example, blocks [1] to blocks [M]). (S340)

Then, this block mapping process is performed for all the references. (S350) The controller 40 maps each node reference to corresponding block data, maps each skin reference to corresponding block data, and prepares for three-dimensional object creation and drawing.

Thereafter, when the block mapping for all the references is completed, the display screen is updated. (S360 to S370)

As shown in FIG. 10, when the corresponding block is in the cache memory, the control unit 40 loads the corresponding block from the cache memory. If the block is not in the cache memory, the control unit 40 requests the BIM server 200, Load the block. (S380 to S395)

The control unit 40 of the BIM data processing system and the terminal apparatus according to the present invention is preferably implemented in a 3D GIS platform in the form of an ADD-ON program.

As described above, the BIM data processing system according to the present invention can be implemented as a computer-readable code on a medium on which a program is recorded. The computer-readable medium includes all kinds of recording devices in which data that can be read by a computer system is stored.

Examples of the computer-readable medium include a ROM, a RAM, a CD-ROM, a magnetic tape, a floppy disk, an optical data storage device and the like, and also implemented in the form of a carrier wave (for example, transmission over the Internet) . The computer may include a control unit 40 of a BIM data processing system or a terminal device.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those skilled in the art that various changes and modifications may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. May be constructed by selectively or in combination. Accordingly, the true scope of the present invention should be determined by the technical idea of the appended claims.

As described above, the present invention has devised a BIM data processing system for quickly and effectively visualizing a large-capacity BIM data according to a view point of a 3D GIS platform, a visualization algorithm suitable for weight reduction of BIM data, and LOD configuration We have implemented a method to visualize BIM-based 3D objects (eg, buildings, bridges, urban facilities, etc.) used in GIS (eg 3D GIS platform) more quickly and efficiently.

The present invention relates to a method and apparatus for interoperating between a BIM and a GIS, that is, for visualizing large-capacity BIM data on a three-dimensional GIS platform, a BIM data is stored in a service data structure capable of fast rendering processing, Structured BIM data can be rendered efficiently.

The BIM data processing system according to the present invention can visualize and render large-capacity BIM data in a building on a 3D GIS platform, and a considerable speed improvement of the 3D GIS platform can be expected.

10: Data receiving unit 20: Data sorting unit
30: Data conversion unit 40:
50: building interior object extraction unit 60: exterior object extraction unit
70: LOD generation unit 80:
100: BIM data processing terminal apparatus 200: BIM server

Claims (15)

1. A BIM data processing terminal apparatus for receiving various BIM data from a BIM server (200) for visualizing building data based on BIM (Building Information Modeling) in a 3D GIS platform,
A data receiving unit 10 for receiving the BIM data of the building from the BIM server 200,
An internal object extraction unit 50 for extracting a building internal object from the input BIM data,
An enclosure object extractor 60 for extracting a building exterior object from the input BIM data,
An LOD generator 70 for weighting the inputted BIM data and generating LOD data for each step,
A storage unit 80 for storing various BIM data extracted and generated for visualizing an object in a building,
It is judged whether or not the current position of the view point is inside the building and it is checked whether or not there is a transparent object which can see the outdoor inside the building in the visible region of the view point, And a controller 40 for selecting a step of the LOD data,
The control unit (40)
First, it is judged whether the view point is inside the building or outside,
When the view point enters the inside of the building, the interior objects of the building are determined as nodes included in the visible region of the current view point,
It is checked whether or not the node reference list for that node is stored in the storage unit 80, the corresponding node reference list is loaded,
Check whether there is a transparent object that can see the outside of the building in the visible area of the view point, and if it exists, check whether the building exterior object is visible through the transparent object,
When the exterior object of the building is visible, the exterior object of the building is determined as a node included in the visible region of the view point,
Determining an LOD stage for expressing an outdoor building by calculating a distance between outdoor buildings visible through the transparent object,
Wherein the BIM data processing terminal performs the screen update by preparing block data related to the LOD steps of the nodes in the determined visible area and the outdoor buildings visible through the transparent object. delete 2. The method according to claim 1, wherein the controller (40)
Checks whether or not a skin reference list related to a building external object of the determined node is stored in the storage unit 80, loads the corresponding skin reference list,
Loads the block data from the storage unit 80,
Mapping the node reference and the skin reference to the block data,
And updates the display screen when the mapping process for all references is completed. The apparatus of claim 1, wherein the LOD generator (70)
A first LOD generation unit 74 for building internal building LOD data for building internal objects extracted by the building internal object extraction unit 50,
And a second LOD generation unit (78) for constructing LOD data for external building by building exterior objects extracted by the exterior object extraction unit (50) . The apparatus of claim 1, wherein the controller (40)
And determining whether or not the current view point is inside the building by using the boundary information of the outside of the building. The apparatus of claim 1, wherein the controller (40)
And adjusts the indoor moving speed of the view point according to a user's mouse operation (movement). The apparatus of claim 1, wherein the controller (40)
If the node reference list is not stored in the storage unit 80, the BIM server 200 requests the BIM server 200 to load the related node reference list into the storage unit 80. [ The apparatus of claim 1, wherein the storage unit (80)
And the BIM data service model, wherein the model includes seven files and one folder, respectively. 9. The method according to claim 8,
A header file including information on the LOD 0 stage, which is the simplest structure among LOD data for building exterior,
Ref_Skin1 to Ref_Skin [N] files for storing block reference information of objects serving as building envelopes for each building exterior LOD (for example, LOD 0 to LOD N)
A Ref_bone file for collecting and storing block reference information of objects to be always displayed regardless of spatial indexing when rendering the inside of a building,
A footprint file that stores extended footprint information of the building to determine if there is a camera in /
A spatial structure file for storing spatial structure information of a building,
And blocks [1] to blocks [M] files and blocksBone files for storing the original geometry information of objects in the building for each LOD / bone. 9. The method according to claim 8,
Wherein the inLOD [N + 1] to inLOD [M] stores spatial indexing information for each step of the building internal LOD data (e.g., LOD N + 1 to LOD M). A method of visualizing BIM data in a BIM data processing system for visualizing building data based on BIM (Building Information Modeling) in a 3D GIS platform,
Determining whether the view point is inside or outside the building;
Determining interior objects of a building as nodes included in a visible region of a current view point when the view point enters an interior of a building;
Checking whether a node reference list for the node is stored in the storage unit 80 and loading the node reference list,
Checking whether or not a transparent object that can see the outside of the building is present in the visible area of the view point and checking if the building exterior object is visible through the transparent object if it exists;
Determining an enclosure object of the building as a node included in a visible region of the viewpoint when the enclosure object of the building is visible;
Determining an LOD level for expressing an outdoor building by calculating a distance between a viewpoint and an outdoor building viewed through a window in a visible region,
And performing screen updating by preparing block data related to LOD steps of nodes in the determined visible area and outdoor buildings visible through the window,
The step of performing the screen update comprises:
Checking whether a skin reference list related to a building envelope object of the determined node is stored in the storage unit 80 and loading the corresponding skin reference list;
Loading block data from the storage unit 80,
Mapping the node reference and the skin reference to the block data,
And updating the display screen when the mapping process for all references is completed. The method of claim 11, wherein the step of determining whether the view point is inside the building comprises:
And determining whether the current view point is inside the building by using the boundary information of the exterior of the building. 12. The method of claim 11,
Further comprising the step of adjusting an indoor moving speed of a view point according to a mouse operation (movement) of the user when the view point enters the inside of the building. 12. The method of claim 11, wherein the step of loading the node reference list comprises:
If the node reference list is not stored in the storage unit 80, requesting the BIM server 200 to load all related node reference lists into the storage unit 80. [ BIM data visualization method. delete

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