CN116992518B

CN116992518B - Method and device for improving data transmission efficiency of three-dimensional CAD system

Info

Publication number: CN116992518B
Application number: CN202311265534.2A
Authority: CN
Inventors: 梅敬成; 苏新新; 何新; 许晓伟; 陈荣昌; 邢胜南
Original assignee: Shandong Huayun 3d Technology Co ltd
Current assignee: Shandong Huayun 3d Technology Co ltd
Priority date: 2023-09-28
Filing date: 2023-09-28
Publication date: 2023-12-26
Anticipated expiration: 2043-09-28
Also published as: CN116992518A

Abstract

The embodiment of the specification discloses a method and a device for improving data transmission efficiency of a three-dimensional CAD system, relates to the field of three-dimensional CAD modeling, and is used for solving the problem of low efficiency when the three-dimensional CAD system transmits based on full data. The method comprises the following steps: the server receives a modeling operation instruction of the browser terminal to create three-dimensional CAD model features based on the modeling operation instruction so as to obtain real-time feature data generated in the process of creating the three-dimensional CAD model features; acquiring incremental data of each real-time characteristic data relative to original data, and classifying the incremental data based on the change type and the data type of the incremental data to obtain data composition elements of various types of the incremental data; and deleting the data component elements based on the data types to obtain incremental data to be transmitted, processing the incremental data to be transmitted based on a preset serialization coding mode to generate structured CAD data, and sending the structured CAD data to the browser terminal.

Description

Method and device for improving data transmission efficiency of three-dimensional CAD system

Technical Field

The present disclosure relates to the field of data transmission technologies, and in particular, to a method and an apparatus for improving data transmission efficiency of a three-dimensional CAD system.

Background

The computer aided design (Computer Aided Design) is to use a computer and graphic equipment thereof to help a designer perform design work, and when designing by using a CAD system, people and machines can exchange information timely, and the display result of each operation can be seen from a graphic terminal screen at any time. In the process, modeling data transmission of a server to a client operation is a premise of subsequent display of product design results, so that an efficient and reliable data transmission mode is an important technology in a three-dimensional CAD system.

In the prior art, when a modeling operation is performed by using a cloud architecture CAD, if full-volume data updating is adopted, the returned information contains all data of a current document besides the change information of the modeling operation on a three-dimensional CAD scene, the data volume at the moment is related to the scale of the current model, and if the model is complex and huge, the full-volume updated data volume is correspondingly more. Because complex and huge model construction is often involved in manufacturing designs such as the existing industrial design, at the moment, a product model cannot be displayed in real time by a client because of overlarge data transmission quantity in a mode based on full data transmission, so that modeling efficiency of the client is low, real-time requirements of a cloud platform cannot be met, and meanwhile, progress of collaborative modeling is also affected.

Disclosure of Invention

In order to solve the above technical problems, one or more embodiments of the present disclosure provide a method and apparatus for improving data transmission efficiency of a three-dimensional CAD system.

One or more embodiments of the present disclosure adopt the following technical solutions:

in one aspect, one or more embodiments of the present disclosure provide a method for improving data transmission efficiency of a three-dimensional CAD system, which is applied to a server, and the method includes:

the method comprises the steps that a server receives a modeling operation instruction of a browser terminal, original data corresponding to the modeling operation instruction are determined, three-dimensional CAD model features are created based on the modeling operation instruction, and real-time feature data generated by each computing unit in the three-dimensional CAD model feature creation process are obtained;

acquiring incremental data of each real-time characteristic data relative to the original data, and classifying the incremental data based on the change type and the data type of the incremental data to obtain data composition elements of various types of incremental data; wherein the change category includes: new addition, update and deletion; the data types include: geometry, topology, display, attributes;

and deleting the data constituent elements based on the data types to obtain incremental data to be transmitted, processing the incremental data to be transmitted based on a preset serialization coding mode to generate structured CAD data, and sending the structured CAD data to the browser terminal.

Optionally, in one or more embodiments of the present disclosure, the puncturing operation is performed on the data constituent element based on the data type to obtain incremental data to be transmitted, which specifically includes:

based on the data types corresponding to the data composition elements, carrying out initial filtering on the incremental data to obtain initial deletion data associated with rendering operation of the browser terminal;

dividing the initial deletion data to obtain geometric data and non-geometric data, and obtaining object features and operation features corresponding to the geometric data; wherein the object features include: round corners, side lines, spheroids and cuboids; the operating features include: stretching, moving, chamfering and rotating;

determining the sequence of each geometric data based on the object features and the operation features of each geometric data, so as to carry out gridding processing on the geometric data based on the sequence and obtain corresponding surface triangular grid data;

acquiring vertex attribute data in the triangular mesh data of each face, summarizing the vertex attribute data, and generating a vertex attribute data set;

taking initial data in the vertex attribute data set as a vertex, traversing the vertex attribute data in the vertex attribute data set to construct a vertex attribute tree, and obtaining repeated vertex attribute data; wherein the repeated vertex attribute data is the same-layer vertex in the vertex attribute number;

Updating a vertex index comparison table corresponding to the vertex attribute data set based on the repeated vertex attribute data, so as to determine the truncated face triangular mesh data based on the vertex index comparison table, and taking geometric data corresponding to the truncated face triangular mesh data and the non-geometric data as incremental data to be transmitted.

Optionally, in one or more embodiments of the present disclosure, the processing the incremental data to be transmitted to generate the structured CAD data based on a preset serialization coding manner specifically includes:

grouping the incremental data to be transmitted based on operation limiting rights corresponding to the data types of the incremental data to be transmitted to obtain a plurality of incremental data transmission groups;

determining a ciphertext attribute decryption policy corresponding to each transmission incremental data group based on the operation limit authority of each transmission incremental data group;

circularly reading the incremental data to be transmitted to construct a Huffman tree, and judging whether matched data exists in each incremental data to be transmitted in the Huffman tree;

if not, acquiring a current Huffman tree node corresponding to the incremental data to be transmitted, so as to judge whether the current Huffman tree node is the node with the highest weight in the nodes with the same frequency;

If yes, increasing the frequency of the current Huffman tree node;

if not, acquiring a node with the highest weight in the same-frequency nodes corresponding to the current Huffman tree node as a replacement node, replacing the current Huffman tree node based on the replacement node, and reconstructing the Huffman tree by taking the replacement node as a father node of the current Huffman tree node to obtain the serialized coded data after the incremental data coding to be transmitted;

and encrypting each group of serialized coded data based on the ciphertext attribute decryption strategy to obtain structured CAD data.

In another aspect, one or more embodiments of the present disclosure provide a method for improving data transmission efficiency of a three-dimensional CAD system, which is applied to a browser terminal, and the method includes:

the browser terminal sends a modeling operation instruction to a server side so as to receive structured CAD data returned by the server in response to the modeling operation instruction;

analyzing the structured CAD data to obtain a classification result of the incremental data, and determining the operation sequence of each incremental data based on the classification result; in the process of creating three-dimensional CAD model features based on the modeling operation instruction by the incremental data based on the server, after acquiring initial incremental data corresponding to the real-time feature data corresponding to each feature calculation unit relative to original data, deleting and obtaining data composition elements of the initial incremental data based on data types;

Sequentially acquiring topology information of the incremental data based on the operation sequence so as to determine a logic structure under a three-dimensional CAD scene corresponding to the modeling operation instruction based on the topology information;

acquiring display data and geometric data in the incremental data to construct corresponding objects in the three-dimensional CAD scene based on the display data and the geometric data;

and determining the feature set of the corresponding object in the three-dimensional CAD scene based on the logic structure, updating different feature sets based on the corresponding object to obtain an updated feature set, and displaying the object in the three-dimensional CAD scene according to the updated feature set.

Optionally, in one or more embodiments of the present disclosure, parsing the structured CAD data to obtain a classification result of the incremental data specifically includes:

acquiring login information of a user logging in the three-dimensional CAD, and judging whether the login information accords with the operation limiting authority of a preset ciphertext attribute decryption strategy;

if yes, decrypting the structured CAD data based on a main private key of the browser terminal to obtain serialized coded data corresponding to the structured CAD data;

And sequentially determining nodes of the Huffman tree based on the serialized encoded data, and realizing reconstruction of the Huffman tree so as to decode the serialized encoded data to obtain corresponding incremental data.

Optionally, in one or more embodiments of the present disclosure, the topology structure of the incremental data is sequentially acquired based on the operation sequence, so as to construct a logic structure in a three-dimensional CAD scene corresponding to the modeling operation instruction based on the topology structure, which specifically includes:

sequentially acquiring modification indexes corresponding to the incremental data based on the operation sequence so as to inquire topology information in the server based on the modification indexes;

and determining a logic connection relation of the incremental data based on the topology information so as to construct a logic structure in a three-dimensional CAD scene corresponding to the modeling operation instruction based on the logic connection relation.

Optionally, in one or more embodiments of the present disclosure, the acquiring display data and geometric data in the incremental data to construct a corresponding object in the three-dimensional CAD scene based on the display data and geometric data specifically includes:

determining an object to be modeled corresponding to the modeling operation instruction based on the geometric data and the display data; wherein, the object to be modeled comprises: a line, a curved surface;

Sequencing the objects to be modeled based on a preset construction sequence table to obtain the processing sequence of the objects to be modeled;

and sequentially acquiring the original data of the object to be modeled based on the processing sequence, so as to modify the original data based on the geometric data and the display data and acquire the construction data of the corresponding object in the three-dimensional CAD scene.

Optionally, in one or more embodiments of the present disclosure, the presenting, according to the updated feature set, an object in the three-dimensional CAD scene specifically includes:

acquiring scene objects contained in the updated feature set, so as to group data corresponding to the updated feature set based on data to be rendered corresponding to each scene object, and acquiring a plurality of rendering data sets;

rendering the rendered data sets based on parallel threads of a preset rendering camera respectively, obtaining a rendering result and displaying the rendering result on a rendering interface;

responding to the triggering operation of a preview button of the rendering interface, and acquiring the identification of each scene object in the updated feature group so as to send a preview model acquisition command to the server side based on the identification;

Receiving the fine model searched by the server side based on the identification, and displaying the fine model on a preview interface; the fine model is obtained by modeling a modeling engine instance at the server side.

In another aspect, in one or more embodiments of the present disclosure, an apparatus for improving data transmission efficiency of a three-dimensional CAD system is provided, where the apparatus is applied to a server, and the apparatus includes:

the server receives modeling operation instructions of the browser terminal, determines original data corresponding to the modeling operation instructions, creates three-dimensional CAD model features based on the modeling operation instructions, and obtains real-time feature data generated by each computing unit in the three-dimensional CAD model feature creation process;

the acquisition module is used for acquiring incremental data of each real-time characteristic data relative to the original data, and classifying the incremental data based on the change type and the data type of the incremental data so as to acquire data composition elements of various types of the incremental data; wherein the change category includes: new addition, update and deletion; the data types include: geometry, topology, display, attributes;

and the sending module is used for deleting the data composition elements based on the data types to obtain incremental data to be transmitted, processing the incremental data to be transmitted based on a preset serialization coding mode to generate structured CAD data, and sending the structured CAD data to the browser terminal.

In another aspect, in one or more embodiments of the present disclosure, an apparatus for improving data transmission efficiency of a three-dimensional CAD system is provided, where the apparatus is applied to a browser, and the apparatus includes:

the receiving module is used for sending the modeling operation instruction to a server side so as to receive the structured CAD data returned by the server in response to the modeling operation instruction;

the analysis module is used for analyzing the structured CAD data to obtain a classification result of the incremental data, and determining the operation sequence of each incremental data based on the classification result; in the process of creating three-dimensional CAD model features based on the modeling operation instruction by the incremental data based on the server, acquiring real-time feature data corresponding to each feature calculation unit, and deleting and obtaining data composition elements of the initial incremental data based on data types after the initial incremental data is obtained relative to the initial incremental data;

the logic construction module sequentially acquires the topological structure of the incremental data based on the operation sequence so as to determine a logic structure under a three-dimensional CAD scene corresponding to the modeling operation instruction based on the topological structure;

the object construction module is used for acquiring display data and geometric data in the incremental data so as to construct a corresponding object in the three-dimensional CAD scene based on the display data and the geometric data;

And the rendering module is used for determining the characteristic groups of the corresponding objects in the three-dimensional CAD scene based on the logic structure, updating different characteristic groups based on the corresponding objects to obtain updated characteristic groups, and displaying the objects in the three-dimensional CAD scene according to the updated characteristic groups.

The above-mentioned at least one technical scheme that this description embodiment adopted can reach following beneficial effect:

and acquiring data of the real-time feature data corresponding to each feature calculation unit in the feature creation process based on the modeling operation instruction, wherein the data is changed relative to the current scene, and the data is used as incremental data. The transmission pressure caused by full data transmission is avoided by acquiring the incremental data. And classifying the incremental data through the data types and the change types to obtain data composition elements, so that the data transmission quantity is reduced by further deleting the data composition elements according to the data types corresponding to the data composition elements, and the transmission speed is further improved. In addition, the incremental data to be transmitted is processed through a preset serialization coding mode, so that the problem of data loss in the data transmission process is reduced, the incremental data to be transmitted is further compressed, and the interaction efficiency between the server side and the browser terminal is remarkably improved.

Drawings

In order to more clearly illustrate the embodiments of the present description or the technical solutions in the prior art, the drawings that are required in the embodiments or the description of the prior art will be briefly described below, it being obvious that the drawings in the following description are only some of the embodiments described in the present description, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art. In the drawings:

fig. 1 is a schematic flow chart of a data transmission method of a three-dimensional CAD system at a server side according to an embodiment of the present disclosure;

FIG. 2 is a schematic flow chart of generating structured CAD data according to embodiments of the present disclosure;

fig. 3 is a schematic flow chart of a data transmission method of a three-dimensional CAD system at a browser end according to an embodiment of the present disclosure;

fig. 4 is a flowchart of a data transmission method of a three-dimensional CAD system based on a cloud architecture according to an embodiment of the present disclosure;

fig. 5 is a schematic diagram of an internal structure of a data transmission device of a three-dimensional CAD system at a server side according to an embodiment of the present disclosure;

fig. 6 is a schematic diagram of an internal structure of a data transmission device of a three-dimensional CAD system at a browser end according to an embodiment of the present disclosure.

Detailed Description

The embodiment of the specification provides a method and a device for improving data transmission efficiency of a three-dimensional CAD system.

In order to make the technical solutions in the present specification better understood by those skilled in the art, the technical solutions in the embodiments of the present specification will be clearly and completely described below with reference to the drawings in the embodiments of the present specification, and it is obvious that the described embodiments are only some embodiments of the present specification, not all embodiments. All other embodiments, which can be made by one of ordinary skill in the art based on the embodiments herein without making any inventive effort, shall fall within the scope of the present disclosure.

As shown in fig. 1, one or more embodiments of the present disclosure provide a flow chart of a data transmission method for a three-dimensional CAD system at a server, where the method uses the server as an execution body, and the method specifically includes the following steps:

s101: the server receives a modeling operation instruction of the browser terminal, determines original data corresponding to the modeling operation instruction, creates three-dimensional CAD model features based on the modeling operation instruction, and obtains real-time feature data generated by each computing unit in the three-dimensional CAD model feature creation process.

When a user performs modeling operation based on a three-dimensional CAD system, for example, when the user creates a stretching boss feature, creates a fillet feature and the like, the browser terminal where the user is located sends a corresponding modeling instruction to the server side. Therefore, in the embodiment of the present disclosure, after receiving the modeling operation instruction sent by the browser terminal, the server side creates the three-dimensional CAD model feature according to the modeling operation instruction. The creating the three-dimensional CAD model features based on the modeling operation instruction includes: creating new three-dimensional CAD model features, deleting three-dimensional CAD model features, and modifying CAD model features. Then, in order to obtain the real-time feature data corresponding to each creation step in the creation process, the real-time feature data generated when each feature calculation unit is executed is sequentially obtained in the three-dimensional CAD model feature creation process. For example, taking an operation when the fillet feature is created for the portal frame model as an example, when the fillet feature needs to be created for the component, the browser terminal sends a modeling operation instruction for creating the fillet feature to the server terminal, and then the server terminal creates a corresponding fillet feature according to the modeling operation instruction after receiving the modeling operation instruction sent by the browser terminal, and data generated in real time in the process of creating the fillet feature is real-time feature data.

Taking the example of creating the fillet feature, after the server creates the corresponding fillet feature according to the modeling operation instruction, real-time feature data is returned to the server, the model is complex, if the full data is returned, the data volume is too large, the data transmission pressure is caused, the data transmission rate is low, and the modeling efficiency is affected. In order to reduce the data volume when the server transmits the feature data to the browser terminal based on the data volume transmission mode, the data in the current scene is acquired as the original data before the feature is created, namely after the modeling operation instruction is received, so that the updated data of the data in the current scene can be acquired in the subsequent feature execution process, and the transmission volume of redundant data is reduced. It will be appreciated that the raw data is the data prior to executing the modeling operation instructions to create the features. The three-dimensional CAD scene is a display scene of a component where the current modeling operation of the browser terminal is located.

S102: acquiring incremental data of each real-time characteristic data relative to the original data, and classifying the incremental data based on the change type and the data type of the incremental data to obtain data composition elements of various types of incremental data; wherein the change category includes: new addition, update and deletion; the data types include: geometry, topology, display, properties.

In order to reduce the data transmission amount and improve the data transmission speed and the modeling interaction efficiency between the server and the browser terminals, in the embodiment of the present disclosure, by comparing the feature data with the original data, the data that changes relative to the original data, that is, the data in the current scene, in the process of creating the feature based on the modeling operation instruction is obtained as the incremental data, and in order to further prune the incremental data, the data transmission amount is further reduced, and in the embodiment of the present disclosure, according to the obtained change category of the incremental data: new add, update, delete, and data type: geometry, topology, display, attributes, etc., to classify the incremental data, thereby obtaining data constituent elements of various types of incremental data. In the example of creating the rounded feature in step S101, the rounded feature is compared with the original data, which is the data in the current scene, so as to record the changed data as incremental data.

Because in the process of creating the feature, for each unit of geometric calculation, the change condition of the data is fed back, namely whether the change condition is newly added, updated or deleted, that is, the change category of the incremental data can be determined, and the incremental data comprises attribute information such as a data mode, and the changed geometric and topological information, that is, the start data type comprises: geometry, topology, display, properties, etc. Taking a certain surface as an example, if unit operations such as clipping and decoration are performed on the surface in the process of participating in modeling calculation, information of the unit operation is recorded. During execution of a feature command, many similar unit operation information is recorded. And when the result is summarized, summarizing the new, modified and deleted data, for example, classifying and summarizing to obtain information of the added, updated and deleted entities, elements, entities and the like, so that the information is assigned to the corresponding attribute according to the topology type of each increment data, such as bus type, star type, ring type and the like. In order to further clarify the association and inclusion relationship between the classification process and the change category thereof and the data composition elements of the data accumulation and increment data, the following corresponding classification procedure is provided as follows:

“{

Data pattern: "",

data: {

New added element [ solution ]

Element 1 {

Geometry {..,

the attribute { },

topology [ ]

}

],

The updating element is [ ],

.....

},

.....

}”

therefore, the visible data composition elements are divided into newly added elements, updated elements and deleted elements according to the change types, and different elements classified based on the data types are contained in each new added element, each updated element and each deleted element. The incremental data is conveniently summarized through classifying the incremental data, and the unnecessary attribute data is deleted by carrying out data screening on the incremental data after classification, so that the unnecessary incremental data is filtered.

S103: and deleting the data constituent elements based on the data types to obtain incremental data to be transmitted, processing the incremental data to be transmitted based on a preset serialization coding mode to generate structured CAD data, and sending the structured CAD data to the browser terminal.

The server side performs deletion operation on the data component elements after obtaining the data types of the incremental data in the step S103, that is, screens out partial geometric and topological information capable of representing the CAD structure, returns the partial geometric and topological information to the client side together with the display data, and deletes the unnecessary attribute data, thereby obtaining the transmission incremental data corresponding to the modeling operation instruction. In order to alleviate the problem of data loss in the serialization and deserialization processes, the embodiment of the specification processes incremental data to be transmitted according to a preset serialization coding mode to generate structured CAD data, so that the safety of data transmission is ensured on the basis of further compressing data quantity. After the server generates the structured CAD data, the obtained CAD structured data is sent to the browser terminal, so that data transmission between the server and the browser terminal is realized.

It should be noted that, the existing full-size data transmission is limited by the model scale, and when the model is more and more complex, the model file size can be increased from tens of megabytes to hundreds of megabytes, and at this time, if each operation is to transmit and update the full-size data, the network and rendering resources are wasted greatly. For example, when modeling is performed, the display data of the portal frame assembly model is about 7.4MB, and if incremental transmission is selected, only the information that changes is updated, for example, the transmission data of the created rounded feature in the above example is only 2.7KB. The transmission quantity of the incremental data transmission is only one ten thousandth of the total transmission compared with the whole assembly data of the total transmission. Therefore, the method remarkably improves the data transmission speed, further improves the modeling interaction efficiency, and can better meet the real-time requirement of the cloud platform.

Specifically, in one or more embodiments of the present disclosure, a puncturing operation is performed on a data constituent element based on a data type to obtain incremental data to be transmitted, which specifically includes the following procedures:

the server side firstly carries out initial filtering on the incremental data according to the data types corresponding to the data composition elements, so as to obtain initial deletion data associated with rendering operation of the browser terminal. The initial pruned data is then partitioned to obtain geometric data and non-geometric data, wherein it is understood that the geometric data is display data that may represent geometric computation processes involved in execution of modeling operational instructions, and may represent topological structures of geometric structure connections, and may represent geometric presentations. And the non-geometric data is attribute data having no geometric meaning, and the like. After dividing the delta data into geometric data and non-geometric data, the operating characteristics associated with the geometric data are acquired, such as: stretching, scanning, lofting, rotating, and the like. The geometric data is then ordered according to the order of the operational features, such as: and stretching and then rounding operation are carried out, and gridding treatment is carried out on the geometric data according to the determined sequence of the geometric data, so that corresponding surface triangular grid data are obtained. It should be noted that, the gridding processing mode is an existing model gridding technology, and a process of obtaining the face triangle mesh data based on gridding processing is not repeated here.

After the surface triangular mesh data are acquired, the server side acquires the vertex attribute data in the surface triangular mesh data, so that the vertex attribute data are summarized to generate a vertex attribute data set. And then taking initial data in the vertex attribute data set as a vertex, constructing a vertex attribute tree by traversing the vertex attribute data in the vertex attribute data set, taking the same-layer vertex in the vertex attribute tree as a repeated vertex, and further obtaining repeated vertex attribute data. And updating the vertex index comparison table corresponding to the vertex attribute data set by filtering the repeated vertex attribute data so as to determine the truncated face triangular mesh data according to the vertex index comparison table, and taking the truncated geometric data and the non-geometric data as incremental data to be transmitted.

Further, as shown in fig. 2, in one or more embodiments of the present disclosure, the processing of incremental data to be transmitted based on a preset serialization coding mode to generate structured CAD data specifically includes the following steps:

s1031: grouping the incremental data to be transmitted according to the operation limiting authority corresponding to the data type of each incremental data to be transmitted, thereby obtaining a plurality of incremental data transmission groups.

S1032: and then determining ciphertext attribute decryption strategies corresponding to the transmission incremental data groups according to the operation limit authority of the transmission incremental data groups, so that the browser terminal with the corresponding decryption attribute decrypts and acquires the data, and the data transmission safety of the three-dimensional CAD system in the collaborative modeling process is enhanced.

S1033: and then circularly reading in the incremental data to be transmitted so as to construct a Huffman tree, and judging whether the matched data exists in the Huffman tree or not in each incremental data to be transmitted.

S1034: and if the matched data does not exist, acquiring the current Huffman tree node corresponding to the incremental data to be transmitted so as to judge whether the current Huffman tree node is the node with the highest weight in the nodes with the same frequency.

S1035: if the current Huffman tree node is the highest weighted node of the same frequency nodes, then the frequency of the current Huffman tree node is increased.

S1036: if the current Huffman tree node is not the node with the highest weight in the nodes with the same frequency, the node with the highest weight in the nodes with the same frequency corresponding to the current Huffman tree node is obtained to be used as a replacement node, the current Huffman tree node is replaced according to the replacement node, and the replacement node is used as a father node of the current Huffman tree node to reconstruct the Huffman tree, so that the serialized coded data after the incremental data to be transmitted is coded is obtained.

S1037: and encrypting each group of serialized coded data according to the ciphertext attribute decryption strategy determined in the process, so as to obtain the structured CAD data.

Based on the above steps S1031-S1037, it can be known that by performing serialization encoding on the incremental data and adding a ciphertext attribute decryption policy in the serialization encoding process, not only is further compression on the incremental data to be transmitted realized, but also encryption on the incremental data to be transmitted is realized, thereby improving the speed and reliability of data transmission.

By the method of S101 to S103, partial geometric and topology information capable of representing the CAD structure is selected for the acquisition of the incremental data and for the further deletion of the incremental data, and returned to the browser terminal together with the display data. By the method, on one hand, only the change data related to the operation is returned, on the other hand, the geometric and topological information with higher data volume ratio is deleted, and only the display data and part of topological data which can support the client rendering and the subsequent operation are returned, so that the data transmission volume is further reduced, and the interaction efficiency of modeling data is also improved.

As shown in fig. 3, in one or more embodiments of the present disclosure, a flow chart of a data transmission method of a three-dimensional CAD system for a browser terminal is provided. The execution subject of the method is a browser terminal, and the method specifically comprises the following steps:

S201: and the browser terminal sends the modeling operation instruction to a server side so as to receive the structured CAD data returned by the server in response to the modeling operation instruction.

When the browser terminal performs modeling operation in the three-dimensional CAD system to create model features, the browser terminal sends a modeling operation instruction to the server side, so that structured CAD data returned by the server in response to the modeling operation instruction is received. It can be understood that the structured CAD data is generated by the server based on the sequential encoding of the incremental data in step S104 in the embodiment of the server, and adding the ciphertext attribute decryption policy in the encoding process.

S202: analyzing the structured CAD data to obtain a classification result of the incremental data, and determining the operation sequence of each incremental data based on the classification result; and in the process of creating the three-dimensional CAD model features based on the modeling operation instruction by the incremental data based on the server, acquiring real-time feature data corresponding to each feature calculation unit, and deleting the initial incremental data based on the data type after acquiring the initial incremental data relative to the original data.

After receiving the structured CAD data returned by the server in response to the modeling operation instruction, the browser terminal analyzes the structured CAD data to obtain a classification result of the incremental data, so that corresponding operation is performed according to the classification result of the incremental data, for example, when the type is newly added, a corresponding object displayed by the client is constructed according to the incremental data, and a scene is updated. And if a plurality of increment data exist, determining the operation sequence of each increment data based on the classification result of the increment data.

Specifically, in one or more embodiments of the present disclosure, parsing the structured CAD data to obtain a classification result of the incremental data specifically includes:

firstly, login information of a user logging in the three-dimensional CAD is obtained, and whether the login information accords with operation limiting authority of a preset ciphertext attribute decryption strategy is judged according to the login information. That is to say, whether the role of the user in the current login information is in the preset ciphertext attribute decryption policy is judged, if the role of the user in the current login information is in the preset ciphertext attribute decryption policy, the operation restriction authority corresponding to the policy is met, and in order to obtain the serialized encoded data encrypted by the main public key based on the policy, in this case, the embodiment of the present disclosure decrypts the structured CAD data according to the main private key of the browser terminal, so as to obtain the serialized encoded data corresponding to the structured CAD data. And sequentially determining nodes of the Huffman tree according to the decrypted serialized encoded data, so that reconstruction of the Huffman tree, namely decoding of the serialized encoded data is realized, and a classification result of the parsed incremental data is obtained.

S203: sequentially acquiring topology information of the incremental data based on the operation sequence so as to determine a logic structure under the three-dimensional CAD scene corresponding to the modeling operation instruction based on the topology information.

After determining the operation sequence of each increment data according to the classification result of the increment data, for example, the increment data is updated after the new increment operation is performed, and at this time, the operation sequence of the increment data is that the increment data of the new increment type is operated first and then the increment data of the update type is operated. After determining the operation sequence, in the embodiment of the present disclosure, in order to determine the logic information of each incremental data, the object corresponding to the incremental data is constructed according to the logic information. In the embodiment of the specification, topology information of incremental data is sequentially acquired according to the operation sequence, so that a logic structure under a three-dimensional CAD scene corresponding to a modeling operation instruction is determined according to the topology information.

Specifically, in one or more embodiments of the present disclosure, a topology structure of incremental data is sequentially acquired based on an operation sequence, so as to construct a logic structure in a three-dimensional CAD scene corresponding to an operation instruction for modeling according to the topology structure, which specifically includes the following steps: and sequentially acquiring modification indexes corresponding to the incremental data according to the operation sequence, so as to inquire topology information in the server according to the modification indexes. And then determining the logic connection relation of the incremental data based on the topology information, and constructing a logic structure under the three-dimensional CAD scene corresponding to the modeling operation instruction according to the logic connection relation. That is, the client queries the corresponding logic structure in the scene according to the index of the modification information in the incremental data, and it can be understood that the object actually displayed in the scene is maintained under the logic structure. For example, the incremental data of a certain update type contains modified attribute information and modified geometric information, at this time, according to the modified attribute information, the corresponding attribute in the logic structure is updated, then according to the modified geometric information, the geometric object is reconstructed, the original object under the logic structure is replaced, and if the operation is deleted, the browser terminal searches and deletes the related data from the scene, so that modeling interaction based on the incremental data is realized.

S204: and acquiring display data and geometric data in the incremental data to construct a corresponding object in the three-dimensional CAD scene based on the display data and the geometric data.

In order to redisplay the updated model object and the front end interface of the browser terminal, display data and geometric data in the incremental data are acquired in the embodiment of the specification, so that corresponding objects in the three-dimensional CAD scene are constructed according to the display data and the geometric data. Specifically, in one or more embodiments of the present disclosure, the method for obtaining display data and geometric data in the incremental data to construct a corresponding object in the three-dimensional CAD scene based on the display data and geometric data specifically includes: determining an object to be modeled corresponding to the modeling operation instruction based on the geometric data and the display data; wherein, the object to be modeled comprises: geometric elements such as lines, curved surfaces, and the like. And then sequencing the objects to be modeled according to a preset modeling object construction sequence table, so as to obtain the processing sequence of the objects to be modeled. And sequentially acquiring the original data of the object to be modeled according to the acquired processing sequence, so as to modify the original data according to the geometric data and the display data and acquire the corresponding object in the three-dimensional CAD scene.

S205: and determining the feature set of the corresponding object in the three-dimensional CAD scene based on the logic structure, updating different feature sets based on the corresponding object to obtain an updated feature set, and displaying the object in the three-dimensional CAD scene according to the updated feature set.

And determining the characteristic groups of the corresponding objects in the three-dimensional CAD scene according to the logic structure, updating different characteristic groups according to the corresponding objects, obtaining updated characteristic groups, and displaying the objects in the three-dimensional CAD scene according to the updated characteristic groups. Specifically, in one or more embodiments of the present disclosure, the displaying, according to the updated feature set, the object in the three-dimensional CAD scene includes the following steps:

scene objects contained in the updated feature set are obtained, so that data corresponding to the updated feature set are grouped according to data to be rendered corresponding to each scene object, and a plurality of rendering data sets are obtained. And then respectively rendering the rendering data sets according to the preset parallel threads of the rendering camera to obtain rendering results and displaying the rendering results on a rendering interface for display. The transmission speed is improved based on the transmission of the incremental data, so that the real-time requirement of the cloud platform, namely, the speed of a display model is high, and the modeling efficiency of a user at a browser terminal is improved. Because the display interface displays the rough model rendered based on the incremental data, when the fine model needs to be acquired, responding to the triggering operation of the preview button of the rendering interface, the browser terminal acquires the identification of each scene object in the updated feature group, and accordingly, a preview model acquisition command is sent to the server side according to the acquired identification of the scene object. The server searches a corresponding fine model according to the identification, and sends the fine model to the browser terminal to be displayed on a preview interface of the browser terminal; the fine model is obtained by modeling a modeling engine instance at the server side.

The embodiment of the present specification as shown in fig. 4 provides a flow chart of a data transmission method of a three-dimensional CAD system based on a cloud architecture, which can be known from the chart: after the user logs in, the user carries out modeling operation, and generates a modeling instruction to be sent to the server. After receiving the modeling instruction sent by the browser terminal, the server executes the modeling instruction to create a feature, and generates feature data corresponding to the modeling instruction in real time so as to generate incremental data by comparing data in a scene in real time. That is, the method and the device can compare with the data in the current scene in the process of creating the features so as to record the changed data, thereby generating the incremental data when the features are created and sending the incremental data to the browser terminal. And after receiving the incremental data, the browser terminal analyzes the incremental data, so that the operation is performed according to the corresponding data classification to realize scene update. In addition, incremental transmission, while capable of significantly reducing the amount of data, is a difficult problem in terms of how to guarantee subsequent modeling operations for the client in the case of display data alone. On the one hand, when the incremental data is calculated, the accuracy of the incremental data of each step is ensured; on the other hand, because only the data is displayed, the identification and attribute information of the element cannot be acquired, and the subsequent modeling operation depends on the information. Thus, in one embodiment of the present description, in addition to transmitting incremental data, more information needed for modeling may be obtained through an interface at the time of use, such as element identification and attribute information needed for creating features, may be obtained through an interface prior to creation and used in creation. In this way, the subsequent modeling operation is ensured to be carried out normally.

As shown in fig. 5, the embodiment of the present disclosure provides a schematic internal structure of a data transmission device of a three-dimensional CAD system applied to a server. A device for improving data transmission efficiency of a three-dimensional CAD system is applied to a server side, and comprises:

the receiving module 701 is configured to receive a modeling operation instruction of a browser terminal, determine original data corresponding to the modeling operation instruction, and create three-dimensional CAD model features based on the modeling operation instruction, so as to obtain real-time feature data generated by each computing unit in the three-dimensional CAD model feature creation process;

the acquiring module 702 is configured to acquire incremental data of each real-time feature data relative to the original data, and classify the incremental data based on a change type and a data type of the incremental data, so as to obtain data constituent elements of each type of incremental data; wherein the change category includes: new addition, update and deletion; the data types include: geometry, topology, display, attributes;

and the sending module 703 is configured to perform a pruning operation on the data component elements based on the data type to obtain incremental data to be transmitted, process the incremental data to be transmitted based on a preset serialization coding mode to generate structured CAD data, and send the structured CAD data to the browser terminal.

As shown in fig. 6, an embodiment of the present disclosure provides an internal structure schematic diagram of a data transmission device of a three-dimensional CAD system applied to a browser terminal, where the device includes:

a receiving module 801, configured to send a modeling operation instruction to a server side, so as to receive structured CAD data returned by the server in response to the modeling operation instruction;

a parsing module 802, configured to parse the structured CAD data to obtain a classification result of the incremental data, so as to determine an operation sequence of each of the incremental data based on the classification result; in the process of creating three-dimensional CAD model features based on the modeling operation instruction by the incremental data based on the server, after acquiring initial incremental data corresponding to the real-time feature data corresponding to each feature calculation unit relative to original data, deleting and obtaining data composition elements of the initial incremental data based on data types;

the logic construction module 803 sequentially acquires the topological structure of the incremental data based on the operation sequence so as to determine a logic structure under a three-dimensional CAD scene corresponding to the modeling operation instruction based on the topological structure;

an object construction module 804, configured to acquire display data and geometric data in the incremental data, so as to construct a corresponding object in the three-dimensional CAD scene based on the display data and geometric data;

And the rendering module 805 is configured to determine a feature set of the corresponding object in the three-dimensional CAD scene based on the logical structure, update different feature sets based on the corresponding object to obtain an updated feature set, and display the object in the three-dimensional CAD scene according to the updated feature set.

In this specification, each embodiment is described in a progressive manner, and identical and similar parts of each embodiment are all referred to each other, and each embodiment mainly describes differences from other embodiments. In particular, for apparatus, devices, non-volatile computer storage medium embodiments, the description is relatively simple, as it is substantially similar to method embodiments, with reference to the section of the method embodiments being relevant.

The foregoing describes specific embodiments of the present disclosure. Other embodiments are within the scope of the following claims. In some cases, the actions or steps recited in the claims can be performed in a different order than in the embodiments and still achieve desirable results. In addition, the processes depicted in the accompanying figures do not necessarily require the particular order shown, or sequential order, to achieve desirable results. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

The foregoing is merely one or more embodiments of the present description and is not intended to limit the present description. Various modifications and alterations to one or more embodiments of this description will be apparent to those skilled in the art. Any modification, equivalent replacement, improvement, or the like, which is within the spirit and principles of one or more embodiments of the present description, is intended to be included within the scope of the claims of the present description.

Claims

1. A method for improving data transmission efficiency of a three-dimensional CAD system, which is applied to a server, the method comprising:

Performing deleting operation on the data composition elements based on the data types to obtain incremental data to be transmitted, processing the incremental data to be transmitted based on a preset serialization coding mode to generate structured CAD data, and sending the structured CAD data to the browser terminal;

and deleting the data composition elements based on the data type to obtain incremental data to be transmitted, wherein the incremental data to be transmitted comprises the following specific steps:

updating a vertex index comparison table corresponding to the vertex attribute data set based on the repeated vertex attribute data to determine truncated face triangular mesh data based on the vertex index comparison table, and taking geometric data corresponding to the truncated face triangular mesh data and the non-geometric data as incremental data to be transmitted;

the processing of the incremental data to be transmitted based on the preset serialization coding mode to generate structured CAD data specifically comprises the following steps:

if yes, increasing the frequency of the current Huffman tree node;

2. A method for improving data transmission efficiency of a three-dimensional CAD system according to claim 1, wherein said method when applied to a browser terminal comprises:

3. The method for improving data transmission efficiency of a three-dimensional CAD system according to claim 2, wherein analyzing the structured CAD data to obtain the classification result of the incremental data comprises:

4. The method for improving data transmission efficiency of a three-dimensional CAD system according to claim 2, wherein sequentially obtaining the topology of the incremental data based on the operation sequence to construct a logic structure in a three-dimensional CAD scene corresponding to the modeling operation instruction based on the topology, specifically comprises:

5. The method for improving data transmission efficiency of a three-dimensional CAD system according to claim 2, wherein obtaining the display data and the geometric data in the incremental data to construct the corresponding object in the three-dimensional CAD scene based on the display data and the geometric data, specifically comprises:

6. The method for improving the data transmission efficiency of the three-dimensional CAD system according to claim 2, wherein the displaying the object in the three-dimensional CAD scene according to the updated feature set specifically comprises:

7. A device for improving data transmission efficiency of a three-dimensional CAD system, for implementing the method for improving data transmission efficiency of a three-dimensional CAD system according to claim 1, applied to a server, the device comprising:

the receiving module is used for receiving modeling operation instructions of the browser terminal, determining original data corresponding to the modeling operation instructions, creating three-dimensional CAD model features based on the modeling operation instructions, and obtaining real-time feature data generated by each computing unit in the three-dimensional CAD model feature creation process;

8. The apparatus for improving data transmission efficiency of a three-dimensional CAD system according to claim 7, wherein said apparatus when applied to a browser comprises:

the analysis module is used for analyzing the structured CAD data to obtain a classification result of the incremental data, and determining the operation sequence of each incremental data based on the classification result; in the process of creating three-dimensional CAD model features based on the modeling operation instruction by the incremental data based on the server, after acquiring initial incremental data corresponding to the real-time feature data corresponding to each feature calculation unit relative to original data, deleting and obtaining data composition elements of the initial incremental data based on data types;