BIM modeling method and system for building model

Abstract

The application relates to the technical field of data processing, in particular to a BIM modeling method and system for a building model, which comprises the following steps: acquiring all models in a BIM construction simulation animation, wherein an observation shot exists in the BIM construction simulation animation; acquiring an evaluation result of the importance degree of the models by analyzing the distance between the observation shot and the models, the observation area of the models, combining the volume, the number of vertices and the deformation state of the models; correcting the importance degree of the models at each moment according to the contact area between adjacent models of each model in the BIM construction simulation animation, and giving each model at each moment the best LOD level. The application gives each model the best LOD level by analyzing the importance degree of the models at each moment in the BIM construction simulation animation and the support degree between the models, so that the fluency of the BIM construction simulation animation is improved without losing the quality of the BIM construction simulation animation.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of data processing, in particular to a BIM modeling method and system for a building model. BACKGROUND

[0002] BIM modeling is a method of visualizing a building model by integrating three-dimensional model, construction progress, resources, technical points and other information. BIM model plays an important role in improving the design efficiency of the building model and optimizing the construction process by modeling the building structure, construction progress and other life cycle information.

[0003] When simulating construction by using a BIM model, all models involved in the BIM construction simulation animation need to be rendered. However, when rendering the models, LOD levels need to be assigned to the models for rendering. The traditional static LOD level rendering method mainly relies on pre-defined geometric simplification levels to balance performance and accuracy, which leads to the fact that the model only focuses on its own information and ignores its dynamic performance in the observation lens, resulting in insufficient accuracy of collision detection and construction scheme verification. The dynamic adaptation capability to real-time view requirements or key areas is lacking, and the models in the BIM construction simulation animation cannot be well rendered. SUMMARY

[0004] The present application provides a BIM modeling method and system for a building model to solve the existing problem that the traditional static LOD level rendering method cannot well render the models in the BIM construction simulation animation.

[0005] The BIM modeling method and system for a building model provided by the present application adopt the following technical solutions:

[0006] In a first aspect, an embodiment of the present application provides a BIM modeling method for a building model, which comprises the following steps:

[0007] All models in a BIM construction simulation animation are obtained, and the observation area of the models observed by an observation lens and the distance between the observation lens and the models at each time are obtained. There is one observation lens in the BIM construction simulation animation;

[0008] The basic importance of the models at each time is obtained according to the observation area of the models, the distance between the observation lens and the models, the volume of the models and the number of vertices of the models. The deformation period importance of the models at each time in the deformation period is obtained according to the difference between the volume change degree of the models and the observation area change degree of the models in the deformation period, combined with the basic importance, and the evaluation result of the importance of the models at each time is determined;

[0009] The downstream model connection of each model is obtained according to the adjacent models of each model in the BIM construction simulation animation; the support degree of each model to the models in the downstream model connection of each model is determined according to the contact area between the models in the downstream model connection of each model; and the evaluation result of the importance degree of each model at each time point is corrected based on the support degree, to determine the corrected importance degree of each model at each time point.

[0010] The initial LOD level and the optimal LOD level of each model at each time point are determined respectively according to the corrected importance degree of each model at each time point.

[0011] Preferably, the specific method for obtaining the basic importance degree of the model at each time point comprises:

[0012] The ratio of the volume of the model to the sum of the observation area of the model at each time point and the preset hyperparameter is calculated as the denominator;

[0013] The product of the ratio and the distance between the observation lens and the model at each time point is subjected to negative mapping by an exponential function, and the normalized result of the product of the negative mapping result and the number of vertices of the model is taken as the basic importance degree of the model at each time point.

[0014] Preferably, the specific method for obtaining the deformation period importance degree of the model at each time point in the deformation time period and determining the evaluation result of the importance degree of the model at each time point comprises:

[0015] The time period in which the model deforms is recorded as the deformation time period of the model;

[0016] The difference between the volume of the model at each time point in the deformation time period and the volume at the previous time point is taken as the numerator;

[0017] The difference between the observation area of the model in the observation lens at each time point in the deformation time period and the observation area at the previous time point is taken as the denominator;

[0018] The ratio of the numerator to the denominator is calculated, and the product of the ratio and the basic importance degree of the model at each time point in the deformation time period is taken as the deformation period importance degree of the model at each time point in the deformation time period;

[0019] The time period in which the model does not deform is recorded as the normal time period of the model, and for each time point in the normal time period of the model, the basic importance degree at the time point is taken as the evaluation result of the importance degree of the model at the time point;

[0020] The time period in which the model deforms is recorded as the deformation time period of the model, and for each time point in the deformation time period of the model, the deformation period importance degree at the time point is taken as the evaluation result of the importance degree of the model at the time point.

[0021] Preferably, the method for obtaining the downstream model association of each model comprises the following specific steps:

[0022] For any one model, the models in the BIM construction simulation animation that are in contact with the model and appear after the model in the BIM construction animation are classified into a first-level downstream model set, and the models in the first-level downstream model set are recorded as first-level downstream models;

[0023] For any first-level downstream model, the models in contact with the first-level downstream model and appearing after the first-level downstream model in the BIM construction animation are classified into a second-level downstream model set, and the models in the second-level downstream model set are recorded as second-level downstream models;

[0024] By analogy, all downstream model sets of any model are obtained, and the downstream model association of each model is constructed in the order of downstream model sets from the highest level to the lowest level; wherein the highest level is the first-level downstream model set, the second-level downstream model set is the next highest level, and the lowest level downstream model set is the last obtained downstream model set of the model.

[0025] Preferably, the method for obtaining the support degree of the model to other models comprises the following specific steps:

[0026] Any one model is recorded as a target model, and any model in any downstream model set of the target model is recorded as a reference model; according to the downstream model association of the target model, a plurality of association chains of the target model pointing to the reference model are obtained;

[0027] Any model in any association chain of the target model pointing to the reference model is recorded as a feature model, the models in the BIM construction simulation animation that are in contact with the feature model and appear after the feature model in the BIM construction animation are recorded as sub-models of the feature model, and the sum of the contact areas between the feature model and all sub-models of the feature model is taken as the total support area of the feature model;

[0028] According to the total support area of all models in all association chains of the target model pointing to the reference model, and the contact area between the downstream models of adjacent levels in all association chains of the target model pointing to the reference model, the support degree of the target model to the reference model is obtained.

[0029] Preferably, the method for obtaining the support degree of the target model to the reference model comprises the following specific steps:

[0030] For any one target model, all feature models of the target model on each association chain are obtained;

[0031] The sum of the accumulations of the total support areas of all feature models on each correlation chain is taken as the single-chain support area of the target model on each correlation chain, and the sum of the accumulations of the single-chain support areas of the target model on all correlation chains is taken as the accumulative support area of the target model;

[0032] The accumulative support areas of all target models are obtained respectively, and the accumulative support areas of all target models are normalized, and the normalized result of the accumulative support area of each target model is taken as the support degree of the target model to the reference model.

[0033] Preferably, the specific method for determining the modified importance degree of each model at each time point comprises:

[0034] The downstream model set of all levels of any one model is obtained, for any one downstream model set, the product of the support degree of each model in each downstream model set to the reference model and the evaluation result of the importance degree of each model at each time point is taken as the importance modification degree of any one model at each time point in all models in the downstream model set of all levels;

[0035] The evaluation result of the importance degree of any one model at each time point is obtained, and the normalized result of the sum of the evaluation result and the importance modification degree is taken as the modified importance degree of any one model at each time point.

[0036] Preferably, the specific method for obtaining the initial LOD level of each model at each time point according to the modified importance degree of each model at each time point comprises:

[0037] The upward rounding result of the product of the modified importance degree of the model at each time point and the preset highest LOD level is taken as the initial LOD level of the model at each time point.

[0038] Preferably, the specific method for assigning the optimal LOD level to each model at each time point comprises:

[0039] For any one model at each time point, the absolute values of the differences between the initial LOD level of each model at each time point and LOD100, LOD200, LOD300, LOD350, LOD400 and LOD500 are calculated respectively, and the LOD level with the smallest absolute value is taken as the optimal LOD level of each model at each time point.

[0040] In a second aspect, another embodiment of the present application provides a BIM modeling system of a building model, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, and the processor implements the steps of any one of the BIM modeling methods of a building model.

[0041] The beneficial effects of the technical solutions of the present application are: the present application analyzes the distance between each model and the observation lens at each time in the BIM construction simulation animation, and the model information captured by the observation lens, and combines the geometric complexity of the model itself and the deformation state of the model, to obtain the evaluation result of the importance degree of each model at each time; then, the support degree of each model to the subsequent model is obtained through the indirect contact area between the models, and the support degree of each model to the subsequent model is combined with the importance degree of the subsequent model to correct the importance degree of each model at each time, and finally the best LOD level of each model at each time is determined through the corrected importance degree of each model at each time, and each model at each time is rendered through the best LOD level of each model at each time, which improves the fluency of the BIM construction simulation animation without losing the quality of the BIM construction simulation animation. BRIEF DESCRIPTION OF DRAWINGS

[0042] In order to more clearly illustrate the technical solutions of the embodiments of the present application or the prior art, the drawings needed in the embodiment or prior art description will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0043] Figure 1 A step flowchart of a BIM modeling method of a building model provided by an embodiment of the present application;

[0044] Figure 2 A downstream model diagram of a model provided by an embodiment of the present application. DETAILED DESCRIPTION

[0045] In order to further illustrate the technical means and effects adopted by the present application to achieve the predetermined invention purpose, the specific embodiments, structures, features and effects of a BIM modeling method and system of a building model according to the present application are described in detail as follows. In the following description, different "one embodiment" or "another embodiment" do not necessarily refer to the same embodiment. In addition, the specific features, structures or characteristics in one or more embodiments can be combined in any suitable form.

[0046] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present application belongs.

[0047] The specific solutions of a BIM modeling method and system of a building model provided by the present application are described in detail below with reference to the drawings.

[0048] Please refer to Figure 1 which shows a step flow chart of a BIM modeling method of a building model provided by an embodiment of the present application, the method comprising the following steps:

[0049] Step S001: Obtain all models in the BIM construction simulation animation, the observation area of each model observed by the observation camera at each time, and the distance between the observation camera and each model.

[0050] It should be noted that the BIM construction simulation animation is a combination of three-dimensional models, construction progress, and resource information, which realizes visual management of the whole process. Before construction, the BIM construction simulation animation can be used to identify process conflicts and safety hazards, reduce engineering rework and accident risks, accurately grasp the construction progress and resource allocation, and improve the work efficiency of the construction site. However, when making the BIM construction simulation animation, all models need to be rendered. If the LOD level of the model is too high, the model rendering will be stalled in the long shot or panoramic shot, causing some constructions in the animation to suddenly simplify or disappear, affecting the visual expression of the construction logic. Especially for building construction models with high LOD levels, the rendering time may be too long. Therefore, the present embodiment proposes a BIM modeling method of a building model, which dynamically adjusts the LOD level of each model at different time periods by analyzing the importance of each model at each construction stage, thereby improving the smoothness of the BIM construction simulation animation.

[0051] Specifically, all drawings of the building construction are obtained, all models are constructed according to all drawings of the building construction, and further, a BIM construction simulation animation is made according to all construction models. Since the process of making models according to construction drawings and making a BIM construction simulation animation through models is a known prior art, it will not be described in detail in the present embodiment.

[0052] It should be further noted that there is an observation camera in the BIM construction simulation animation, which observes the complete process of the BIM construction simulation animation.

[0053] Further, the observation area of each model observed by the observation camera at each time and the distance between the observation camera and each model are obtained.

[0054] Step S002: Obtain the basic importance degree of the model at each time according to the observation area of the model, the distance between the observation camera and the model, the volume of the model, and the number of vertices of the model at each time; obtain the deformation period importance degree of the model at each time in the deformation period according to the difference between the volume change degree of the model and the observation area change degree of the model during deformation, combined with the basic importance degree; and determine the evaluation result of the importance degree of the model at each time.

[0055] According to the observation area of the observation lens observing the model and the distance between the observation lens and the model at each time, combined with the volume and the number of vertices of the model, the basic importance degree of the model at each time in the normal time period is obtained; according to the volume change trend of the model, the observation area change trend of the observation lens observing the model and the basic importance degree, the deformation period importance degree of the model at each time in the deformation time period is obtained.

[0056] It should be noted that the embodiment is a BIM modeling method for a building model, specifically, by assigning each model in the BIM construction simulation animation at each time a best LOD level, each model in the BIM construction simulation animation at each time is rendered, and the fluency of the BIM construction simulation animation is improved without losing the quality of the BIM construction simulation animation. The BIM construction simulation animation contains a large number of models, and the geometric complexities of the models are different. In order to display the related features of the models with high geometric complexity in the BIM construction simulation animation, the models with high geometric complexity need to be assigned a high LOD level. Meanwhile, the position of the observation lens in the BIM construction simulation animation is not fixed, and when the position of the observation lens changes, the performance of each model in the BIM construction animation will be affected, therefore, the relative position change between the model and the observation lens needs to be combined to adjust the LOD level of each model in the BIM construction simulation animation.

[0057] Preferably, in one specific embodiment of the present application, for any time, taking the yth time in the normal time period of the model as an example, the normal time period is the time period when the model does not deform; according to the distance between the observation lens and the model at the yth time in the normal time period of the model, the observation area of the observation lens observing the model at the yth time in the normal time period of the model, the volume of the model and the number of vertices of the model, the basic importance degree of the model at the ith time in the normal time period is obtained, and the specific calculation formula is:

[0058]

[0059] In the formula, L y represents the basic importance degree of the model at the yth time in the normal time period; V represents the volume of the model, S y represents the observation area of the observation lens observing the model at the yth time; h yrepresents the distance between the observation camera and the model at the yth moment; D represents the number of vertices of the model; a is a preset hyperparameter, and a is a positive number not greater than 0.5, which is not specially limited in the present application, and a = 0.01 is taken as an example in the embodiment, and the purpose is to avoid the case that the denominator is 0 in the process of performing fractional operation; exp() represents an exponential function with a natural constant as a base; norm[] represents a Min-Max linear normalization function.

[0060] It should be noted that the higher the importance degree of the base model when the model does not deform, the higher the LOD level should be given to the model; represents the ratio between the volume of the model and the observation area of the model observed by the observation camera at the yth moment, when The smaller the value of h y The smaller the value of h y Compared with the influence degree of the number of vertices D on the base importance degree, the reason for such calculation is that the detail features of the model when the model does not deform have a more intuitive impact on the visual quality of the BIM construction simulation animation than the number of vertices. h y Compared with the influence degree of the number of vertices D on the base importance degree, the reason for such calculation is that the detail features of the model when the model does not deform have a more intuitive impact on the visual quality of the BIM construction simulation animation than the number of vertices.

[0061] It should be further noted that as the BIM construction simulation animation simulates the construction, some models in the BIM construction simulation animation will deform in the simulation process (such as the gradual spread of the floor and the gradual erection of the column), and the deformation process of the model reflects the core activities of the construction stage, and the process details will directly affect the feasibility and safety of the subsequent process, and when the model is completed, it is often a prerequisite for the construction of the subsequent process, therefore, when the model deforms, a higher LOD level should be given to it to display the related detail features of the model with high precision; meanwhile, the deformation of the model in the BIM construction simulation animation has a deformation direction, when the deformation direction of the deformed model and the observation direction of the observation camera tend to be perpendicular, the observation camera can more clearly present the detail features in the deformation process of the model, and therefore a higher LOD level should be given to the deformed model, and further combined with the base importance degree of the model, the importance degree of the deformed model at each moment in the deformation process is obtained.

[0062] Preferably, in one specific embodiment of the present application, the time period in which the model is deformed is recorded as the deformation time period of the model, for the i-th time point in the deformation time period of any model, the deformation period importance of the i-th time point in the deformation time period of the model is obtained, combined with the observation area of the model observed by the observation lens at the i-th time point and the i-1-th time point in the deformation time period of the model, and the volume of the model at the i-th time point and the i-1-th time point in the deformation time period of the model, the deformation period importance of the i-th time point in the deformation time period of the model is obtained, and the specific calculation formula is:

[0063]

[0064] In the formula, A i represents the deformation period importance of the i-th time point in the deformation time period of the model; L' i represents the basic importance of the i-th time point in the deformation time period of the model; ΔV' i,i-1 represents the difference between the volumes of the model at the i-th time point and the i-1-th time point in the deformation time period; ΔS' i,i-1 represents the difference between the observation areas of the model observed by the observation lens at the i-th time point and the i-1-th time point in the deformation time period.

[0065] It should be noted that ΔV' i,i-1 represents the change in volume of the model at two adjacent time points, reflecting the actual deformation degree of the model at the i-th time point, and the greater the value of ΔV' i,i-1 , the greater the deformation degree of the model at the i-th time point; ΔS ′ i,i-1 represents the change in the observation area of the model obtained by the observation lens, reflecting the deformation degree of the model at the i-th time point in the observation lens, and the greater the ratio between them represents the difference between the deformation degree of the model observed in the observation lens and the actual deformation degree of the model, and the greater the ratio, the more difficult it is for the observation lens to reflect the actual deformation speed of the model, that is, the observation direction of the observation lens and the deformation direction of the model tend to be parallel, at this time, even if the model is given a high LOD level, the observation lens still cannot capture the detailed features in the deformation process of the model, and the necessity of giving the model a high LOD level is smaller.

[0066] It is further needed to be explained that if the model is in a stable state without deformation, the basic importance degree of the model at each time in the normal time period is taken as the evaluation result of the model importance degree at the time; and for the model in the deformation period, the deformation period importance degree of each time determined on the basis of the basic importance degree and the real deformation and the observed deformation is taken as the evaluation result of the importance degree of the model at each time in the deformation period.

[0067] Up to now, the evaluation result of the importance degree of the model at each time is obtained.

[0068] Step S003: obtaining the downstream model connection of each model according to the adjacent models of each model in the BIM construction simulation animation; determining the support degree of each model to the models in the downstream model connection of each model according to the contact area between the models in the downstream model connection of each model; correcting the evaluation result of the importance degree of the model at each time based on the support degree to determine the corrected importance degree of each model at each time.

[0069] It is needed to be explained that the model in the subsequent process in the BIM construction simulation animation is established on the basis of the previous process model, i.e. each model will provide support for the model after it, and the more important the model supported by the model, the more important the model providing support, so after obtaining the importance degree of the model at each time through step S002, the importance degree of the model at each time is further corrected in combination with the importance degree of the model after each model in the BIM construction animation to obtain the corrected importance degree of the model at each time.

[0070] Preferably, in one specific embodiment of the present application, for any model, the models in the BIM construction simulation animation in contact with the model and appearing after the model in the BIM construction animation are classified into a first-level downstream model set, and the models in the first-level downstream model set are recorded as first-level downstream models.

[0071] For any first-level downstream model, the models in contact with the first-level downstream model and appearing after the first-level downstream model in the BIM construction animation are classified into a second-level downstream model set, and the models in the second-level downstream model set are recorded as second-level downstream models.

[0072] By analogy, until all downstream model sets of any model are obtained, and the downstream model connection of each model is constructed in the order of the downstream model set from the highest level to the lowest level, the highest level is the first-level downstream model set, the second-level downstream model set is the next highest level, and the lowest level downstream model set is the last obtained downstream model set of the model. As shown in Figure 2 Fig. 1 is a downstream model connection diagram of a model with n-level downstream model sets.

[0073] It should be noted that generally the greater the contact area between the model and its downstream model, the greater the support provided by the model to its downstream model, and therefore the support provided by the model to its downstream model can be obtained therefrom, and the importance of the model can be corrected according to the support provided by the model to its downstream model and the importance of the downstream model.

[0074] Preferably, in one specific embodiment of the present application, any model is recorded as a target model, and any downstream model of the target model is recorded as a reference model; a plurality of association chains of the target model pointing to the reference model are obtained according to the association of the downstream model of the target model;

[0075] Any model in any association chain of the target model pointing to the reference model is recorded as a feature model, and a model in the BIM construction simulation animation that is in contact with the feature model and appears after the feature model in the BIM construction animation is recorded as a sub-model of the feature model, and the sum of the contact areas between the feature model and all the sub-models of the feature model is taken as the total support area of the feature model;

[0076] The support degree of the target model to the reference model is obtained according to the total support area of all the models in all the association chains of the target model pointing to the reference model and the contact area between the adjacent level downstream models in all the association chains of the target model pointing to the reference model, and the specific calculation process is as follows:

[0077] For any target model, first, all the feature models of the target model on each association chain are obtained; second, the cumulative sum of the total support areas of all the feature models on each association chain is taken as the single-chain support area of the target model on each association chain; then, the cumulative sum of the single-chain support areas of the target model on all the association chains is taken as the cumulative support area of the target model.

[0078] Further, the cumulative support areas of all the target models are obtained respectively, and the cumulative support areas of all the target models are normalized, and the normalized result of the cumulative support area of each target model is taken as the support degree of the target model to the reference model.

[0079] Wherein, normalization is a well-known technology in the field of data processing, and the specific process will not be repeated, and the normalization methods include but are not limited to maximum-minimum normalization and exponential normalization, and the present application does not specially limit the normalization method. Preferably, in the present embodiment, the exponential normalization function softmax function is used to normalize the cumulative support areas of all the target models.

[0080] It should be noted that the model directly supports its first-level downstream model, but indirectly supports all downstream models of the second level and below, for example, the model supports its second-level downstream model through its first-level downstream model; the greater the contact area between the model and its downstream model, the greater the degree of support provided by the model to its downstream model, and therefore the degree of support provided by the model to the downstream model is obtained through the contact area between the adjacent level downstream model sets of the model, and the evaluation result of the importance degree of the model is further corrected by taking the degree of support provided by the model to the downstream model as a weight.

[0081] Preferably, in one specific embodiment of the present application, for any model at the jth moment, the corrected importance degree of the model at the jth moment is obtained according to the evaluation result of the importance degree of all models related to the model and the downstream models of the model at the jth moment, and the degree of support of the model to all models related to the downstream models of the model at the jth moment, and the specific calculation process is as follows:

[0082] First, obtain all level downstream model sets of any one model, for any one downstream model set, take the quadratic accumulation result of the product of the support degree of each model in each downstream model set to the reference model and the evaluation result of the importance degree of each model at the jth moment on all models in all level downstream model sets as the importance correction degree of any one model at the jth moment;

[0083] Secondly, obtain the evaluation result of the importance degree of any one model at the jth moment, and take the normalization result of the sum of the evaluation result and the importance correction degree as the corrected importance degree of any one model at the jth moment.

[0084] Wherein, normalization is a well-known technology in the field of data processing, and the specific process will not be repeated, and the normalization methods include but are not limited to maximum-minimum normalization and exponential normalization, and the present application does not specially limit the normalization method. Preferably, in the present embodiment, the maximum-minimum normalization method is used to calculate the corrected importance degree of the model.

[0085] It should be noted that the model is a prerequisite for the construction of the downstream model in the subsequent process, so the more important the downstream model is and the higher the support degree of the model to the downstream model is, the more important the model is, and therefore the support degree of each model in each downstream model set of the model is taken as a weight, and the importance degree of all downstream models of the model is combined to correct the importance degree of the model, so as to accurately evaluate the importance degree of the model.

[0086] At this point, the corrected importance degree of all models at each moment is obtained.

[0087] Step S004: According to the correction importance of each model at each time, the initial LOD level and the best LOD level of each model at each time are determined respectively.

[0088] It should be noted that after obtaining the correction importance of all models at each time through step S003, the LOD level of the model at each time can be assigned according to the correction importance of all models at each time, so as to render each model in the BIM construction simulation animation at each time, thereby improving the fluency of the BIM construction simulation animation without losing the quality of the BIM construction simulation animation.

[0089] Preferably, in one specific embodiment of the present application, a highest LOD level γ is preset, and the specific value of the γ can be set by itself in combination with the actual situation, and the present embodiment does not make hard requirements, and in the present embodiment, γ = 500 is taken as an example for description; for any model at the jth time; the correction importance of the model at the jth time is combined with the preset highest LOD level γ to obtain the initial LOD level of the model at the jth time, and the specific calculation formula is:

[0090] R j = round(γ × W j )

[0091] In the formula, R j represents the initial LOD level of the model at the jth time; γ represents the preset highest LOD level; W j represents the correction importance of the model at the jth time, and round() is a rounding function.

[0092] Further, the absolute values of the differences between the initial LOD level of the model at the jth time and LOD100, LOD200, LOD300, LOD350, LOD400, and LOD500 are calculated respectively, and the corresponding LOD level with the smallest absolute value is taken as the best LOD level of the model at the jth time.

[0093] Similarly, the best LOD level of each model at each time is obtained, and each model at each time is rendered through the best LOD level of each model at each time, so as to improve the fluency of the BIM construction simulation animation without losing the quality of the BIM construction simulation animation.

[0094] Another embodiment of the present application provides a BIM modeling system of a building model, which comprises a memory, a processor, and a computer program stored in the memory and executable on the processor, and the processor implements a BIM modeling method of a building model in steps S001 to S004 when executing the computer program.

[0095] It should be noted that the above-mentioned examples are only used to illustrate the technical solutions of the present application, but not limit the same; although the present application has been described in detail with reference to the foregoing examples, those skilled in the art should understand that the technical solutions recorded in the foregoing examples can still be modified, or some technical features can be replaced by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application, and should be included in the protection scope of the present application.

[0096] Each of the embodiments in the specification is described in a progressive manner, and the same or similar parts between the embodiments can be referred to each other, and each embodiment mainly describes the difference from other embodiments.

Claims

1. A BIM modeling method of an architectural model, characterized by, The method comprises the following steps: Obtaining all models in a BIM construction simulation animation, an observation area of a model observed by an observation camera at each time and a distance between the observation camera and the model, wherein there is one observation camera in the BIM construction simulation animation; Obtaining a basic importance degree of the model at each time according to the observation area of the model at each time, the distance between the observation camera and the model, a volume of the model and a number of vertices of the model, obtaining a deformation period importance degree of the model at each time in a deformation time period of the model according to a difference between a volume change degree of the model and an observation area change degree of the model in the deformation time period, combining the basic importance degree, determining an evaluation result of the importance degree of the model at each time; Obtaining a downstream model connection of each model according to adjacent models of each model in the BIM construction simulation animation, determining a support degree of each model to the models in the downstream model connection of each model according to a contact area between the models in the downstream model connection of each model, correcting the evaluation result of the importance degree of the model at each time based on the support degree, and determining a corrected importance degree of each model at each time. The basic importance degree of the model at each time is obtained by the following specific method:

2. The BIM modeling method of an architectural model according to claim 1, wherein, The sum of the observation area of the model at each time and a preset hyperparameter is taken as a denominator, and a ratio of the volume of the model to the denominator is calculated. The product of the ratio and the distance between the observation camera and the model at each time is subjected to exponential function negative mapping, and a normalized result of the product of the negative mapping result and the number of vertices of the model is taken as the basic importance degree of the model at each time. The deformation period importance degree of the model at each time in the deformation time period of the model is obtained by the following specific method:

3. The BIM modeling method of an architectural model according to claim 2, wherein, The time period in which the model deforms is recorded as a deformation time period of the model. The difference between the volume of the model at each time and the volume at the previous time in the deformation time period is taken as a numerator. The difference between the observation area of the model at each time and the observation area of the model at the previous time in the observation camera in the deformation time period is taken as a denominator. The ratio of the numerator to the denominator is calculated, and the product of the ratio and the basic importance degree of the model at each time in the deformation time period is taken as the deformation period importance degree of the model at each time in the deformation time period. The time period in which the model does not deform is recorded as a normal time period of the model, and for each time in the normal time period of the model, the basic importance degree at each time is taken as the evaluation result of the importance degree of the model at the time. The time period in which the model deforms is recorded as a deformation time period of the model, and for each time in the deformation time period of the model, the deformation period importance degree at each time is taken as the evaluation result of the importance degree of the model at the time. The downstream model connection of each model is obtained by the following specific method:

4. The BIM modeling method of an architectural model according to claim 1, wherein, ​ For any one model, models in the BIM construction simulation animation that are in contact with the model and appear after the model in the BIM construction animation are classified into a first-level downstream model set, and the models in the first-level downstream model set are recorded as first-level downstream models; For any first-level downstream model, models that are in contact with the first-level downstream model and appear after the first-level downstream model in the BIM construction animation are classified into a second-level downstream model set, and the models in the second-level downstream model set are recorded as second-level downstream models; The process is repeated until all downstream model sets of any model are obtained, and a downstream model association network of each model is constructed in the order of downstream model sets from the highest level to the lowest level; wherein the highest level is the first-level downstream model set, the second-level downstream model set is the next highest level, and the lowest level downstream model set is the last obtained downstream model set of the model.

5. The BIM modeling method of an architectural model according to claim 1, wherein, The specific method for obtaining the support degree of the model to other models includes: Any one model is recorded as a target model, and any model in any downstream model set of the target model is recorded as a reference model; according to the downstream model association network of the target model, a plurality of association chains of the target model pointing to the reference model are obtained; Any model in any association chain of the target model pointing to the reference model is recorded as a feature model, models in the BIM construction simulation animation that are in contact with the feature model and appear after the feature model in the BIM construction animation are recorded as child models of the feature model, and the sum of the contact areas between the feature model and all child models of the feature model is taken as the total support area of the feature model; The support degree of the target model to the reference model is obtained according to the total support area of all models in all association chains of the target model pointing to the reference model, combined with the contact areas between downstream models of adjacent levels in all association chains of the target model pointing to the reference model.

6. The BIM modeling method of an architectural model according to claim 5, wherein, The specific method for obtaining the support degree of the target model to the reference model includes: For any one target model, all feature models of the target model on each association chain are obtained; The cumulative sum of the total support areas of all feature models on each association chain is taken as the single-chain support area of the target model on each association chain; The cumulative sum of the single-chain support areas of the target model on all association chains is taken as the cumulative support area of the target model; The cumulative support areas of all target models are obtained respectively, and the cumulative support areas of all target models are normalized, and the normalized result of the cumulative support area of each target model is taken as the support degree of the target model to the reference model.

7. The BIM modeling method of an architectural model according to claim 4, wherein, The specific method for determining the correction importance degree of each model at each time includes: For any one model, all levels of downstream model sets are obtained, for any one downstream model set, the product of the support degree of each model in each downstream model set to the reference model and the evaluation result of the importance degree of each model at each time is taken as the importance correction degree of any one model at each time in all models in all levels of downstream model sets; The evaluation result of the importance of any one model at each time is obtained, and a normalized result of the sum of the importance correction degrees is taken as a corrected importance of any one model at each time.

8. The BIM modeling method of an architectural model according to claim 1, wherein, The specific method for obtaining the initial LOD level of each model at each time according to the corrected importance of each model at each time comprises: The product of the corrected importance of the model at each time and the preset highest LOD level is taken as the initial LOD level of the model at each time.

9. The BIM modeling method of an architectural model according to claim 1, wherein, The specific method for assigning the optimal LOD level to each model at each time comprises: For any one model at each time, the absolute values of the differences between the initial LOD level of each model at each time and LOD100, LOD200, LOD300, LOD350, LOD400 and LOD500 are calculated respectively, and the LOD level with the smallest absolute value is taken as the optimal LOD level of each model at each time. 10.A BIM modeling system of an architectural model, comprising a memory, a processor, and a computer program stored on the memory and executable on the processor, wherein the computer program comprises the following steps of: The computer program is executed by the processor to realize the steps of the BIM modeling method of the building model according to any one of claims 1-9.

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