CN106528760A

CN106528760A - IFC-standard-based analysis model working method applied to engineering project

Info

Publication number: CN106528760A
Application number: CN201610972997.6A
Authority: CN
Inventors: 许元
Original assignee: SIMUTECH Inc
Current assignee: SIMUTECH Inc
Priority date: 2016-11-04
Filing date: 2016-11-04
Publication date: 2017-03-22

Abstract

The invention provides an IFC-standard-based analysis model working method applied to an engineering project. The method comprises the following steps: S1, importing IFC-standard-based data into an analyzer to be analyzed, and then constructing the analyzed data; S2, extracting analyzed model geometrical information; S3, extracting analyzed model attribute information; and S4, performing triangulated grid modeling on the extracted model geometrical information. If the current market product needs to support an IFC-standard-based model, the product has to be analyzed; however, the method provided by the invention provides IFC analysis, the analyzed data can be applied to construction industry, railway industry and the like, and the analysis method is quick and convenient.

Description

For analytical model method of work of the engineering project based on IFC standards

Technical field

The present invention relates to computer software fields, more particularly to a kind of parsing mould for engineering project based on IFC standards Type method of work.

Background technology

Industry benchmark classification (Industry Foundation Classes, IFC) is the international co-operation for being found in nineteen ninety-five Alliance (International Alliance for Interoperability, IAI) for building industry make to measure towards right Elephant, neutral, open product model data standard.As ISO STEP building industry special case, IFC inherit and use for reference STEP a large amount of ripe achievement in research, to promote the data exchange of building industry software as target, with system, participant Independence, can effectively support the number of the data exchange and building Life cycle between building trade each application system According to management.Used as the building products data standard based on BIM theories, IFC is subject to the extensive support of people in the industry, come true on BIM model data standards.Especially in terms of building and construction of railways, IFC normal datas are needed as carrier, but it is above-mentioned There is following defect in industry：

First, IFC entities storehouse (being completely independent exploitation) are bound

IFC document parsers

IFC geometric model transducers；

Shortcoming：

Each IFC standard one is issued, and its standard content and form are i.e. it has been determined that the loaded down with trivial details repetition in binding IFC entities storehouse Work；

IFC geometry is separated with IFC resolvers, actually used loaded down with trivial details, is not incorporated into together, after obtaining IFC data, in addition it is also necessary to Incoming geometric model transducer；

2nd, using closing source resolution binding library, and using closing source geometrical processor；

Shortcoming：

Close source uncontrollable, which relies on heavier to closing source resolution storehouse developer, once go wrong, it is difficult to repair；Geometry with Parsing separately processes somewhat cumbersome.

The content of the invention

It is contemplated that at least solving technical problem present in prior art, especially innovatively propose a kind of for work Analytical model method of work of the journey project based on IFC standards.

In order to realize the above-mentioned purpose of the present invention, the invention provides a kind of solution for engineering project based on IFC standards Analysis model method of work, comprises the steps：

Data based on IFC standards are imported resolver parsing, build the data after parsing by S1；

S2, takes out the model geometric information after parsing；

S3, takes out the model attributes information after parsing；

S4, carries out triangle meshes moulding to the model geometric information after taking-up.

The described analytical model method of work for engineering project based on IFC standards, it is preferred that the S1 includes：

By the model based on IFC standards by parsing storehouse parsing, build high-level language and can know the data for taking, reflect with former data Penetrate；

S1-1, the model original data based on IFC standards adopt EXPRESS languagies performance,

S1-2, EXPRESS language is representation language, it is impossible to directly which is read out and is operated, so needing base In the data that the model original data binding construction of IFC standards is the operable reading of high-level language.

The described analytical model method of work for engineering project based on IFC standards, it is preferred that the S1-2 built Journey includes：

A, IFC standard high-level languages are mapped one by one, the IfcDoor classes in IFC standards, EXPRESS transmission expression side Formula is as follows：

ENTITY IfcDoor represent the category of an entity as a door entity class, the every other ENTITY entities under which Property will inherit to ENTITY entities, EXPRESS transmission representation language in, this literary style is similar to the succession in high-level language It is polymorphic, for example there are ENTITY IfcRoot entities under ENTITY IfcDoor entities, this shows that IfcDoor doors entity will be after IfcRoot entity attributes are held, so the attribute of the IfcRoot under IfcRoot will be by the entity of all succession IfcRoot Possess, wherein including：GloabId represents a global displacement mark ID for inheriting the entity to IfcRoot, OwnerHistory represents the developer's information for inheriting the entity to IfcRoot, and the value of OwnerHistory attributes is in institute It is the same in having the entity for inherit IfcRoot, Description is represented and inherited the simple of the entity to IfcRoot to one Description, certainly, an entity can be inherited to multiple other entities, it is also possible to possess other father's entity attributes, or can be after The subtype entity of its some parent is held, and the IfcObjectDefintion under IfcRoot is also inherited in IfcDoor, one Entity attributes are inherited to father's entity attributes except having, and also have some free attributes, and in IfcDoor, free attribute is only There is OverallHeight to show that wall is high, OverallWidth shows the width of body of wall；

B, from definition of the Express language to IfcDoor door entities in above-mentioned IFC, in the definition of IFC standards, IfcDoor apoplexy due to endogenous wind includes many attributes, wherein have being inherited from parent, also has oneself exclusive, but is all as expression language Speech, it illustrates some entity attributes, but can not operate on it, so needing to an IFC files institute table The information for reaching is mapped to which using high-level language, is conveniently operated with, and how explained later maps, and how to be operated：

C, an entity transmit the ENTITY of language performance equivalent to a class class, above-mentioned use EXPRESS IfcDoor entities, are class IfcDoor defined in high-level language, inherit to other entity attributes, can be without table Show, because when the entity which needs succession is defined, having been defined for those father's entity attributes, directly inheriting other class Type, can inherit its publicly-owned variable of public for possessing, and protect protection variables, automatically so using c# high-level languages During binding mapping EXPRESS language, it is only necessary to define its free attribute, in such as IfcDoor entities, attribute only needs to definition OverallWidth and OverallHeight, and the publicly-owned variables of public are defined as, because other attribute books are inherited to door reality Body, if other entities are inherited from IfcDoor, then they can equally possess the two entity attributes, our binding mappings The purpose of EXPRESS transmission language is to make the attribute for transmitting representation language expression by EXPRESS can be good at being grasped Make, and in c# high-level languages, except the attribute defined in a type, additionally it is possible to defined function, these function stands Operation to the function of this type, such as can define a bool isOpen function in IfcDoor this type, use To judge whether this door is to open, after so binding, can be to using the inoperable IFC of EXPRESS representation languages before Entity is operated；

D, certainly, in order that operation is simpler, we can also except the outer definition other types of IFC entities binding it is auxiliary Help, by measurement data structure I fcMeasure, carry out data auxiliary, in this way, it is possible to avoid re-defining this structure from And cause error rate to increase or complexity increase；

E, by IFC standards binding mapping for high-level language a series of class libraries, if IFC standards have renewal, or which is opened The standard of source place binding can not meet demand, then need oneself addition binding, such as IfcRailWay types, and this type is special For the entity type of Chinese Railway customization, so there is no the mapping of IfcRailWay entities in existing storehouse of increasing income, in reality Using in, if including this entity in an IFC file, we are can not to obtain and inoperable to its attribute, so Which can be bound as binding IfcDoor, and add conventional handling function IfcMeasure measureLenght For measuring the length of a certain section of railway track；

F, binding mapping IFC standards are previous work, it was demonstrated that have a storehouse literary for being based on IFC master patterns physics Part parse, and one based on IFC master pattern physical files be by a series of mutual references example combination into text, Before each example (#1,2 ... .) its reference name in file internal is represented, equal sign string as upper case below is represented should Type of the example in standard (binding mapping), the content behind type in bracket are corresponded with the attribute in java standard library, Thus, it is possible to parsing structure be carried out to IFC normative documents by java standard library noted earlier.

The described analytical model method of work for engineering project based on IFC standards, it is preferred that the S2 includes：

Geological information is taken out from the data after binding construction parsing；

S2-1, based on the data model of IFC standards, the component is and possesses shape data, the component parent in IFC standards For IfcProduct, which has representation attributes, i.e. shape data, travels through shape data, obtains wherein all of IfcGeometricRepresentationItem, as geometric shape item, it should be noted that there are visible components and possess outer Graphic data, but which does not possess geometric shape item, and such directly to ignore, the profile item of taking-up is boundary model (B-Rep), several What body (Solid), extrusion solid (excute-Solid), grid (Mesh), this step are first cached, and are grasped for subsequent meshesization Make.

The described analytical model method of work for engineering project based on IFC standards, it is preferred that the S3 includes：

Model attributes information is taken out from data of the binding construction based on IFC standards

S3-2, based on the data model of IFC standards, the component be possess body parent be IfcProduct, which has Property attributes and propertySet property sets, i.e. attribute data, due to all models of binding construction of step before Data, this portion can directly take out model geometric data property, for subsequent development.

To the model geometric data gridding moulding after taking-up

S3-A, below the data model of IFC standards, its geometric data for getting：

Cylinder：Based on IFC standards data model definitions cylinder geological information be two points, three faces, wherein three Face includes two planes, a curved surface；

Plane：Data model definitions plane geometry information based on IFC standards is a vertex set, a series of and faces, If there is gap in plane, inner boundary is defined as；

Boolean：The components such as the model window based on IFC standards are IfcOpening, represent gap；

Type is produced as described in second step around here, and the geometric shape item after taking-up is the type in polytype, and It is more than above-mentioned several, such as following table：

Grey parts are geometric type, although geometric type is a lot, but the grid moulding talked about below, can by it is various not Same type geometry item is output as same format.

S3-B, carries out geometric modeling using opencascade (OCC), and the meaning of geometric modeling is to retouch IFC standards The geological information stated is converted to the data (being commonly called as triangle gridding data) for being available for renderer to render, this kind of data not classifying type, Form is all unified, below the citing rasterizing process by taking cylinder as an example

In IFC expression, by three faces, two points are constituted cylinder, and modeling process is：

Each face possesses area, and two points possess coordinate, thus can calculate, the upper and lower two disks boundary perimeter of cylinder, And Cylinder Surface, before moulding device gridding, it is processed as plane, that is to say, that equally can determine four edge lengths of curved surface, Before moulding, a Modeling precision can be transmitted to moulding device, according to this Modeling precision, two sides up and down to curved surface, be pinpointed, And determining radius, thus moulding is completed；

Certainly, a kind of formative method of each type correspondence, but substantially thinking is the same；Data after moulding are pressed Certain format is stored, and can deposit gridded data using text by binary system, this method by text；

S3-C, the different type geometric data grid that IFC standards are provided is turned to after tri patch data, then write-read takes grid Include vertex list, normal list, and topology to close in the interface of dough sheet data of formatting, wherein rasterizing tri patch data System：

Triangle：If Atria summit is respectively：

P1：(X1, Y1, Z1)

P2：(X2, Y2, Z2)

P3：(X3, Y3, Z3)

So vertex list：P_list { X1, Y1, Z1, X2, Y2, Z2, X3, Y3, Z3 }

Topological relation list：T_list { Pcount, P1_Index, P2_Index, P3_Index }

I.e.：{ 3,0,1,2 }

Normal follows right hand rule, and the data of rasterizing render use for rendering tool below.

In sum, as a result of above-mentioned technical proposal, the invention has the beneficial effects as follows：

Existing market product if desired supports the model based on IFC standards, it is necessary to which, through resolving, this method is provided The parsing of IFC, the data after parsing are available for building trade, railway systems etc. to use, and analytic method is quick.

The additional aspect and advantage of the present invention will be set forth in part in the description, and partly will become from the following description Obtain substantially, or recognized by the practice of the present invention.

Description of the drawings

The above-mentioned and/or additional aspect and advantage of the present invention will become from the description with reference to accompanying drawings below to embodiment It is substantially and easy to understand, wherein：

Fig. 1 is fundamental diagram of the present invention.

Specific embodiment

Embodiments of the invention are described below in detail, the example of the embodiment is shown in the drawings, wherein from start to finish Same or similar label represents same or similar element or the element with same or like function.Below with reference to attached The embodiment of figure description is exemplary, is only used for explaining the present invention, and is not considered as limiting the invention.

In describing the invention, it is to be understood that term " longitudinal direction ", " horizontal ", " on ", D score, "front", "rear", The orientation or position relationship of the instruction such as "left", "right", " vertical ", " level ", " top ", " bottom " " interior ", " outward " is based on accompanying drawing institute The orientation for showing or position relationship, are for only for ease of the description present invention and simplify description, rather than indicate or imply the dress of indication Put or element must have specific orientation, with specific azimuth configuration and operation, therefore it is not intended that to the present invention limit System.

In describing the invention, unless otherwise prescribed and limit, it should be noted that term " installation ", " being connected ", " connection " should be interpreted broadly, and for example, can be mechanically connected or electrically connect, it is also possible to be the connection of two element internals, energy Enough it is joined directly together, it is also possible to be indirectly connected to by intermediary, for the ordinary skill in the art, being capable of basis Concrete condition understands the concrete meaning of above-mentioned term.

As shown in figure 1, the present invention discloses a kind of analytical model method of work for engineering project based on IFC standards, wrap Include following steps：

S2, takes out the model geometric information after parsing；

S3, takes out the model attributes information after parsing；

ENTITY IfcDoor represent the category of an entity as a door entity class, the every other ENTITY entities under which Property will inherit to ENTITY entities, EXPRESS transmission representation language in, have ENTITY under ENTITY IfcDoor entities IfcRoot entities, this shows that IfcDoor doors entity will inherit IfcRoot entity attributes, so under IfcRoot The attribute of IfcRoot will be possessed by the entity of all succession IfcRoot, wherein including：GloabId represent one inherit to The global displacement mark ID of the entity of IfcRoot, OwnerHistory represent a developer for inheriting the entity to IfcRoot Information, the value of OwnerHistory attributes is the same in the entity of all succession IfcRoot, and Description represents right One is inherited being briefly described for the entity to IfcRoot, and certainly, an entity can be inherited to multiple other entities, it is also possible to Possess other father's entity attributes, or the subtype entity of its some parent can be inherited, also inherit in IfcDoor IfcObjectDefintion under IfcRoot, entity attributes are inherited to father's entity attributes except having, and are also had Free attribute, in IfcDoor, free attribute only OverallHeight shows that wall is high, and OverallWidth shows body of wall Width；

C, an entity transmit the ENTITY of language performance equivalent to a class rank class, above-mentioned use EXPRESS IfcDoor entities, are class IfcDoor defined in high-level language, inherit to other entity attributes, can be without table Show, because when the entity which needs succession is defined, having been defined for those father's entity attributes, directly inheriting other class Type, can inherit its publicly-owned variable of public for possessing, and protect protection variables, automatically so using c# high-level languages During binding mapping EXPRESS language, it is only necessary to define its free attribute, in such as IfcDoor entities, attribute only needs to definition OverallWidth and OverallHeight, and the publicly-owned variables of public are defined as, because other attribute books are inherited to door reality Body, if other entities are inherited from IfcDoor, then IfcDoor can equally possess the two entity attributes, our binding mappings The purpose of EXPRESS transmission language is to make the attribute for transmitting representation language expression by EXPRESS can be good at being grasped Make, and in c# high-level languages, except the attribute defined in a type, additionally it is possible to defined function, these function stands Operation to the function of this type, such as can define a bool isOpen function in IfcDoor this type, use To judge whether this door is to open, after so binding, can be to using the inoperable IFC of EXPRESS representation languages before Entity is operated；

D, certainly, has asked and has caused operation simpler, we can also except the outer definition other types of IFC entities binding it is auxiliary Help, by measurement data structure I fcMeasure, carry out data auxiliary, in this way, it is possible to avoid re-defining this structure from And cause error rate to increase or complexity increase；

To the model geometric data gridding moulding after taking-up

S3-A, below the data model of IFC standards, its geometric data for getting：

S3-2, carries out geometric modeling using opencascade (OCC), and the meaning of geometric modeling is to retouch IFC standards The geological information stated is converted to the data (being commonly called as triangle gridding data) for being available for renderer to render, this kind of data not classifying type, Form is all unified, below the citing rasterizing process by taking cylinder as an example

S3-3, the different type geometric data grid that IFC standards are provided is turned to after tri patch data, then write-read takes grid Include vertex list, normal list, and topology to close in the interface of dough sheet data of formatting, wherein rasterizing tri patch data System：

Triangle：If Atria summit is respectively：

P1：(X1, Y1, Z1)

P2：(X2, Y2, Z2)

P3：(X3, Y3, Z3)

So vertex list：P_list { X1, Y1, Z1, X2, Y2, Z2, X3, Y3, Z3 }

Topological relation list：T_list { Pcount, P1_Index, P2_Index, P3_Index }

I.e.：{ 3,0,1,2 }

A complete resolver is integrated into, comprising all relevant treatment, the incoming model based on IFC standards is only needed, just Can direct access model and geometric data.

Advantage：

For the entity storehouse binding of IFC standards need not be done it yourself, reusability is higher.

Wrong modification ability is sought using the process positioning well that goes wrong to developer and subsequent user in storehouse of increasing income.

Incorporate the operation of IFC all related resolutions, comprising it is several how, error rate is reduced, easy to operate, once incoming IFC Model, user without the need for being concerned about operation, without importing geometrical processor again.

Secondary development can be carried out to storehouse of increasing income, it is ensured that last result meets the requirement of oneself.

In the description of this specification, reference term " one embodiment ", " some embodiments ", " example ", " specifically show Example ", or the description of " some examples " etc. mean specific features with reference to the embodiment or example description, structure, material or spy Point is contained at least one embodiment or example of the present invention.In this manual, to the schematic representation of above-mentioned term not Identical embodiment or example are referred to necessarily.And, the specific features of description, structure, material or feature can be any One or more embodiments or example in combine in an appropriate manner.

Although an embodiment of the present invention has been shown and described, one of ordinary skill in the art it will be appreciated that：Not These embodiments can be carried out with various changes, modification, replacement and modification in the case of the principle and objective that depart from the present invention, this The scope of invention is limited by claim and its equivalent.

Claims

1. a kind of analytical model method of work for engineering project based on IFC standards, it is characterised in that comprise the steps：

S2, takes out the model geometric information after parsing；

S3, takes out the model attributes information after parsing；

2. the analytical model method of work for engineering project based on IFC standards according to claim 1, its feature exist In the S1 includes：

By the model based on IFC standards by parsing storehouse parsing, build high-level language and can know the data for taking, map with former data；

S1-2, EXPRESS language is representation language, it is impossible to directly which is read out and is operated, so needs will be based on IFC Data of the model original data binding construction of standard for the operable reading of high-level language.

3. the analytical model method of work for engineering project based on IFC standards according to claim 2, its feature exist In the S1-2 building processs include：

A, IFC standard high-level languages are mapped one by one, the IfcDoor classes in IFC standards, and EXPRESS transmission expression way is such as Under：

Used as a door entity class, the every other ENTITY entities under which represent that an entity attributes will to ENTITY IfcDoor Can inherit to ENTITY entities, in EXPRESS transmission representation languages, this literary style is more similar to the succession in high-level language State, for example, have ENTITY IfcRoot entities under ENTITY IfcDoor entities, and this shows that IfcDoor doors entity will be inherited IfcRoot entity attributes, so the attribute of the IfcRoot under IfcRoot will be gathered around by the entity of all succession IfcRoot Have, wherein including：GloabId represents global displacement mark an ID, OwnerHistory for inheriting the entity to IfcRoot The developer's information for inheriting the entity to IfcRoot is represented, the value of OwnerHistory attributes is in all succession IfcRoot Entity in be the same, Description is represented and is inherited being briefly described for the entity to IfcRoot to one, certainly, one Entity can be inherited to multiple other entities, it is also possible to possessed other father's entity attributes, or can be inherited its some parent Subtype entity, also inherit the IfcObjectDefintion under IfcRoot in IfcDoor, entity attributes except There is succession to father's entity attributes, also have some free attributes, in IfcDoor, free attribute only has OverallHeight Show that wall is high, OverallWidth shows the width of body of wall；

B, from definition of the Express language to IfcDoor door entities in above-mentioned IFC, in the definition of IFC standards, IfcDoor Apoplexy due to endogenous wind includes many attributes, wherein have being inherited from parent, also has oneself exclusive, but is all that, used as representation language, it opens up Some entity attributes is shown, but can not operate on it, so needing to the information expressed by an IFC file Which is mapped using high-level language, conveniently operated with, how explained later maps, and how to be operated：

C, an entity transmit the ENTITY IfcDoor realities of language performance equivalent to a class class, above-mentioned use EXPRESS Body, is class IfcDoor defined in high-level language, inherits to other entity attributes, can be without representing, because fixed When adopted its needs the entity inherited, those father's entity attributes are had been defined for, directly inherit other class types, can be automatic Its publicly-owned variable of public for possessing, and protect protection variables are inherited, so using c# high-level language binding mappings During EXPRESS language, it is only necessary to define its free attribute, in such as IfcDoor entities, attribute only needs to definition OverallWidth and OverallHeight, and the publicly-owned variables of public are defined as, because other attribute books are inherited to door reality Body, if other entities are inherited from IfcDoor, then they can equally possess the two entity attributes, our binding mappings The purpose of EXPRESS transmission language is to make the attribute for transmitting representation language expression by EXPRESS can be good at being grasped Make, and in c# high-level languages, except the attribute defined in a type, additionally it is possible to defined function, these function stands Operation to the function of this type, such as can define a bool isOpen function in IfcDoor this type, use To judge whether this door is to open, after so binding, can be to using the inoperable IFC of EXPRESS representation languages before Entity is operated；

D, certainly, in order that operation is simpler, we can also aiding in except the outer other types that define of IFC entities binding, By measurement data structure I fcMeasure, data auxiliary is carried out, in this way, it is possible to avoid re-defining this structure so as to lead Error rate is caused to increase or complexity increase；

E, by IFC standards binding mapping for high-level language a series of class libraries, if IFC standards have renewal, or its storehouse of increasing income Bound standard can not meet demand, then need oneself addition binding, such as IfcRailWay types, and this type is exclusively in The entity type of state's railway customization, so there is no the mapping of IfcRailWay entities in existing storehouse of increasing income, in practical application In, if including this entity in an IFC file, we are can not to obtain and inoperable to its attribute, so can picture Binding IfcDoor is equally bound to which, and the conventional handling function IfcMeasure measureLenght of addition are used for Measure the length of a certain section of railway track；

F, binding mapping IFC standards are previous work, it was demonstrated that have the storehouse can be for based on IFC master pattern physical file solutions Analysis, and one based on IFC master pattern physical files be by a series of mutual references example combination into text, every Before one example (#1,2 ... .) its reference name in file internal is represented, equal sign string as upper case below represents the example Type in standard (binding mapping), the content behind type in bracket are corresponded with the attribute in java standard library, thus Parsing structure can be carried out to IFC normative documents by java standard library noted earlier.

4. the analytical model method of work for engineering project based on IFC standards according to claim 1, its feature exist In the S2 includes：

S2-1, based on the data model of IFC standards, the component is and possesses shape data, and in IFC standards, component parent is IfcProduct, which has representation attributes, i.e. shape data, travels through shape data, obtains wherein all of IfcGeometricRepresentationItem, as geometric shape item, it should be noted that there are visible components and possess outer Graphic data, but which does not possess geometric shape item, and such directly to ignore, the profile item of taking-up is boundary model (B-Rep), several What body (Solid), extrusion solid (excute-Solid), grid (Mesh), this step are first cached, and are grasped for subsequent meshesization Make.

5. the analytical model method of work for engineering project based on IFC standards according to claim 4, its feature exist In the S3 includes：

6. the analytical model method of work for engineering project based on IFC standards according to claim 1, its feature exist In the S3 includes：

To the model geometric data gridding moulding after taking-up

S3-A, below the data model of IFC standards, its geometric data for getting：

Cylinder：Based on IFC standards data model definitions cylinder geological information be two points, three faces, wherein three bread Include two planes, a curved surface；

Plane：Data model definitions plane geometry information based on IFC standards is a vertex set, a series of and faces, if There is gap in plane, be defined as inner boundary；

Type is produced as described in second step around here, and the geometric shape item after taking-up is the type in polytype, and incessantly It is above-mentioned several, such as following table：

Grey parts are geometric type, although geometric type is a lot, but the grid moulding talked about below, can be by various inhomogeneities Type geometry item is output as same format.

S3-B, carries out geometric modeling using opencascade (OCC), and the meaning of geometric modeling is by described by IFC standards Geological information is converted to the data (being commonly called as triangle gridding data) for being available for renderer to render, this kind of data not classifying type, form Whole is unified, below the citing rasterizing process by taking cylinder as an example

Each face possesses area, and two points possess coordinate, thus can calculate, the upper and lower two disks boundary perimeter of cylinder, and justifies Curved surface of column, before moulding device gridding, is processed as plane, that is to say, that equally can determine four edge lengths of curved surface, in moulding Before, a Modeling precision can be transmitted to moulding device, according to this Modeling precision, two sides up and down to curved surface, be pinpointed, and really Determine radius, thus moulding is completed；

Certainly, a kind of formative method of each type correspondence, but substantially thinking is the same；By the data after moulding by certain Form is stored, and can deposit gridded data using text by binary system, this method by text；

S3-C, the different type geometric data grid that IFC standards are provided is turned to after tri patch data, then write-read takes rasterizing Vertex list, normal list, and topological relation are included in the interface of dough sheet data, wherein rasterizing tri patch data：

Triangle：If Atria summit is respectively：

P1：(X1, Y1, Z1)

P2：(X2, Y2, Z2)

P3：(X3, Y3, Z3)

So vertex list：P_list { X1, Y1, Z1, X2, Y2, Z2, X3, Y3, Z3 }

Topological relation list：T_list { Pcount, P1_Index, P2_Index, P3_Index }

I.e.：{ 3,0,1,2 }