Parameterized modeling method for digital simulation model of GH-based dougong in Qing Dynasty of China

Abstract

The application discloses a GH-based parameterized modeling method for a Chinese Qing-dynasty dougong digital simulation model, and through parameterized modeling, the modeling of a Qing-style anqiao dougong body section and a column head section component can be driven by a computer parameter, the modeling characteristics of the component are autonomously selected to generate a related component model, the appearance modeling of the component can be calculated, the mortise-and-tenon structure meeting the installation requirements of an ancient building component can be solved, the model can be provided for virtual three-dimensional rendering, and an accurate digital model can be provided for numerical control machine tool processing. The application solves the problem in the prior art that the research on the creation of a dougong by using Grasshopper can only be used for modeling display, and the model data cannot be directly used for numerical control processing of the dougong.

Description

Technical Field

[0001] This invention relates to the field of building construction technology, specifically to a parametric modeling method for a digital simulation model of Chinese Qing Dynasty dougong (bracket sets) based on GH (Gestalt Graph). Background Technology

[0002] Dougong (bracket sets), or dougong, is a crucial component of traditional Chinese architecture, serving not only as a load-bearing element but also as a significant decorative element. During the Qing Dynasty, the form of dougong exhibited particularly distinctive characteristics. Many contemporary cultural tourism projects involve constructing Qing-style replicas. However, the manufacturing process for dougong components is complex and requires manual creation of templates and markings for each component, followed by processing using traditional tools and relatively primitive power tools. Due to the numerous and varied styles of dougong components, this process is extremely labor-intensive, and traditional methods of dougong manufacturing are gradually being abandoned by traditional building construction companies.

[0003] In modern society, some factories processing antique architectural components have begun using CNC machine tools to manufacture bracket sets (dougong). However, using CNC machine tools requires a prerequisite: a model file must be provided for computer simulation of the machining toolpath. Therefore, for a given project, considerable time is needed to create the model file on the computer. This process is time-consuming, inefficient, and because modeling is done manually, there is a certain probability of error.

[0004] With the increasing application of BIM (Building Information Modeling) technology in building construction, parametric technology is also constantly developing. Some studies have used Grasshopper (GH, a visual programming language) to create dougong (bracket sets), including those in the Qing Dynasty and Song Dynasty styles. However, some of these studies suffer from overly scattered nodes and low levels of intelligence, requiring selection from numerous nodes, resulting in low efficiency. Others fail to create reasonable mortise and tenon dougong, serving only as a display of form, and the model data cannot be directly used for CNC machining of the dougong. Summary of the Invention

[0005] To overcome the shortcomings of existing technologies, a parametric modeling method for digital simulation models of Chinese Qing Dynasty bracket sets based on Grasshopper is provided. This method addresses the problem that existing research on bracket sets created using Grasshopper can only be used for aesthetic demonstration, and the model data cannot be directly used for CNC machining of the bracket sets.

[0006] To achieve the above objectives, a parametric modeling method for a digital simulation model of Chinese Qing Dynasty dougong (bracket sets) based on GH (Gestalt Graph) is provided, comprising the following steps:

[0007] The components of the Qing Dynasty dougong structure are divided into fixed-style components and variable-style components. The variable-style components include an arch body, a front head connected to the front end of the arch body, and a rear tail connected to the rear end of the arch body. Different shapes of the front head and the rear tail form different components.

[0008] In GH software, create a set of shapes for the fixed-style components and a set of shapes for the variable-style components. The set of shapes for the variable-style components includes a subset of the arch, the front head, and the rear tail.

[0009] Obtain the structural parameters of the digital simulation model of the bracket set, including the number of bracket set layers, the value of the bracket opening, the style, quantity and installation position of the components;

[0010] Based on the structural parameters, retrieve the component shapes from the shape set and place them at the original point;

[0011] After placing the component shape at the original point and scaling it according to the bucket opening value, the component shape at the original point is used as the subject of the Boolean operation, and the horizontal arch is used as the subtrahend of the Boolean operation to perform Boolean transport to obtain the actual shape of the vertical arch.

[0012] The installation position of the horizontal arch member of the next layer is calculated and passed to the calculation node of the next layer structure to obtain the digital simulation model of the bracket set by stacking the components layer by layer from bottom to top. When the variable style component is retrieved, the variable style component is formed by splicing the shapes of the subsets of the arch body, the front head and the rear tail respectively.

[0013] Furthermore, the subsets of the arch, the front head, and the rear tail are stored in the Brep node and retrieved through a combination of parameters ValueList and SteamFilter.

[0014] Furthermore, when retrieving the variable style components of the corner bracket set, the cross-sections of the front head, the rear tail, and the body of a single horizontal arch member are determined based on the structural parameters, and then the shape of the single horizontal arch member is generated. The structural parameters include the number of layers of the upturned components of the corner bracket set, the number of layers of the single horizontal arch member in the corner bracket set, and the number of the single horizontal arch member from the center to the eaves.

[0015] Furthermore, when the number of layers of the upturned members of the corner bracket is equal to 1, it is determined that the front head of the single transverse arch member is a grasshopper head or other members that do not protrude outwards.

[0016] When the number of layers of the ang and qiao members of the corner bracket set is greater than 1, the number of layers of the ang and qiao members of the corner bracket set is equal to the number of layers of the single horizontal arch member in the corner bracket set, and the number of the single horizontal arch member from the center to the eave overhang is equal to the number of layers of the single horizontal arch member in the corner bracket set, the front protruding head of the single horizontal arch member is a xiang gong, otherwise the front protruding head of the single horizontal arch member is a grasshopper head or other member that does not protrude outward;

[0017] When the number of layers of the ang and qiao members of the corner bracket set is greater than 1, and the number of layers of the ang and qiao members of the corner bracket set is not equal to the number of layers of the single horizontal arch member in the corner bracket set, the front protruding head of the single horizontal arch member is an ang head or a qiao head.

[0018] Further, when the number of layers of the ang and qiao members of the corner bracket set corresponds to the number of layers of the single horizontal arch member in the corner bracket set, and the number of layers of the ang and qiao members of the corner bracket set is greater than 1, the cross section of the single horizontal arch member is a full-material arch, otherwise it is a single-material arch.

[0019] Further, when the number of the single horizontal arch member from the center to the eave overhang is equal to 1, the rear tail part is a center melon arch; when the number of the single horizontal arch member from the center to the eave overhang is equal to 2, the rear tail part is a center wan arch; when the number of the single horizontal arch member from the center to the eave overhang is equal to 3, the rear tail part is a center arch plate;

[0020] If the number of the single horizontal arch member from the center to the eave overhang is not equal to 1, and the number of layers of the ang and qiao members of the corner bracket set is equal to the number of layers of the single horizontal arch member in the corner bracket set: when the number of the single horizontal arch member from the center to the eave overhang is equal to the number of layers of the single horizontal arch member in the corner bracket set, the rear tail part is a xiang gong; when the difference between the number of the single horizontal arch member from the center to the eave overhang and the number of layers of the single horizontal arch member in the corner bracket set is 1, the rear tail part is a single-material wan arch; when the difference between the number of the single horizontal arch member from the center to the eave overhang and the number of layers of the single horizontal arch member in the corner bracket set is 2, the rear tail part is a drag arch plate; when the difference between the number of the single horizontal arch member from the center to the eave overhang and the number of layers of the single horizontal arch member in the corner bracket set is greater than 2, the rear tail part is not processed;

[0021] If the number of individual horizontal arch members from the center to the eaves is not equal to 1, and the number N of the upturned members in the corner bracket is not equal to the number of layers of the individual horizontal arch member in the corner bracket, then the rear end is a single-tiered bracket set when the number of individual horizontal arch members from the center to the eaves is equal to the number of layers of the individual horizontal arch member in the corner bracket; when the difference between the number of individual horizontal arch members from the center to the eaves and the number of layers of the individual horizontal arch member in the corner bracket is 1, the rear end is a single-tiered bracket set; when the difference between the number of individual horizontal arch members from the center to the eaves and the number of layers of the individual horizontal arch member in the corner bracket is 2, the rear end is a tie beam; when the difference between the number of individual horizontal arch members from the center to the eaves and the number of layers of the individual horizontal arch member in the corner bracket is greater than 2, the rear end is not processed.

[0022] The beneficial effects of this invention are that the parametric modeling method for digital simulation models of Qing Dynasty dougong (bracket sets) based on GH (Gesture Theory) can use computer parameters to drive the shape of the body and column heads of Qing-style dougong, and autonomously select the shape characteristics of the components to generate relevant component models. It can not only calculate the appearance shape, but also find the mortise and tenon structure that meets the installation requirements of ancient building components, provide models for virtual 3D rendering, and provide accurate digital models for CNC machine tool processing. Attached Figure Description

[0023] Other features, objects, and advantages of this application will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0024] Figure 1 This is a flowchart illustrating the modeling method for the bracket sets of the Platycladus and Stigmata families according to an embodiment of the present invention.

[0025] Figure 2 This is a flowchart of the method for modeling corner brackets according to an embodiment of the present invention.

[0026] Figure 3 This is a schematic diagram of the partitioning of the rear bumper with two humps according to an embodiment of the present invention.

[0027] Figure 4 This is a schematic diagram illustrating the combined use of parameters ValueList and SteamFilter in a standardized component application according to an embodiment of the present invention.

[0028] Figure 5 This is a schematic diagram showing the variation in the width of the arch eye and tenon of the column head arch bracket in an embodiment of the present invention.

[0029] Figure 6 This is a schematic diagram showing the placement points of the components of the double-curved three-angled flat-body bracket set according to an embodiment of the present invention.

[0030] Figure 7 This is a plan view of the sixth layer of the dougong (bracket set) of the Chongqiao San'angjiaoke (double-curved three-cornered bracket set) according to an embodiment of the present invention.

[0031] Figure 8 This is a partition diagram of the corner bracket arch components according to an embodiment of the present invention.

[0032] Figure 9 This is a logic diagram for determining the front head of the corner bracket component in an embodiment of the present invention.

[0033] Figure 10 This is a logic diagram for judging the rear end of the corner bracket component in an embodiment of the present invention.

[0034] Figure 11 This is a schematic diagram of the mortise and tenon joint positioning points of the corner bracket component according to an embodiment of the present invention.

[0035] Figure 12 This is a logic diagram for judging the matching of each item in the list of mortise and tenon positioning points Q of the corner bracket component in an embodiment of the present invention.

[0036] Figure 13 This is a logic diagram for judging the matching of each item in the list of mortise and tenon positioning points P of the corner bracket component in an embodiment of the present invention. Detailed Implementation

[0037] The present application will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, only the parts relevant to the invention are shown in the accompanying drawings.

[0038] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0039] Reference Figures 1 to 13 As shown, this invention provides a parametric modeling method for a digital simulation model of Chinese Qing Dynasty dougong (bracket sets) based on GH (Gross Graphica Sinica), comprising the following steps:

[0040] S1. The components of the Qing Dynasty dougong structure are divided into fixed-style components and variable-style components. Variable-style components include the arch body, the front head connected to the front end of the arch body, and the rear tail connected to the rear end of the arch body. Different shapes of the front head and the rear tail form different components.

[0041] S2. In the GH software, create a set of shapes for fixed-style components and a set of shapes for variable-style components. The set of shapes for variable-style components includes a subset of the arch, the front head, and the rear tail.

[0042] S3. Obtain the structural parameters of the digital simulation model of the bracket set. The structural parameters include the number of bracket set layers, the value of the bracket opening, the style, quantity and installation position of the components.

[0043] S4. Based on the structural parameters, retrieve the component shapes from the shape set and place them at the original point;

[0044] S5. After placing the component shape at the original point and scaling it according to the bucket opening value, use the component shape at the original point as the main body of the Boolean operation, and use the horizontal arch as the subtracted item of the Boolean operation to perform Boolean transport to obtain the actual shape of the vertical arch.

[0045] S6. Calculate the installation position of the horizontal arch member of the next layer and transfer it to the calculation node of the next layer structure to stack the members layer by layer from bottom to top to obtain the digital simulation model of the bracket. When calling up the variable style member, the variable style member is formed by splicing the shapes of the subsets of the arch body, the front head and the rear tail respectively.

[0046] Specifically, the dougong structure includes five types of components: qiao, ang, gong, fang, and dou. Among them, the qiao, ang, gong, and fang components can be classified as arch components, that is, horizontal arch components or longitudinal arch components.

[0047] For the longitudinal brackets in the flat-body bracket structure, taking a single component of the flat-body bracket with two angs and upturned ends as an example, such as... Figure 3 As shown, it is divided into three parts: section A is the front head of the component, section B is the arch body of the component, and section C is the rear tail.

[0048] The variations of the front head include raised head, upturned head, and grasshopper head. On some non-official Ming and Qing buildings, you can also see some deformed raised head components, which are carved with various patterns.

[0049] Variations at the rear include upturned head, six-part head, hemp leaf head, chrysanthemum head, etc.

[0050] Therefore, the options for the front head are made into a selectable list, and the options for the rear tail are also made into a selectable list. The length of the bracket body is calculated by the number of jumps (front and back), and the number of jumps is related to the number of layers. Because sometimes the rear tail component does not jump, it is assumed that it does not jump. The front head may not jump even on the top layer. Assuming the correction coefficient is J, the number of layers from the first layer of the bracket upwards is M, and the length of the bracket body is ((M-1)×2-J)×3.

[0051] The original shape of the longitudinal arch is the result of combining and merging the original C segment, the calculated B segment, and the A segment after moving the length of the B segment.

[0052] As a preferred implementation, the subsets of the arch, the front head, and the rear tail are stored in the Brep node and retrieved through a combination of the parameters ValueList and SteamFilter.

[0053] Specifically, such as Figure 4 As shown, after the shapes of the horizontal arch members of the bracket set are formed into subsets, the required horizontal arch members are selected at specific locations as needed. Similarly, regions A and C of the vertical arch members (angqiao components) also form subsets, thereby controlling the shape of the bracket set. In GrassHopper, standardized components can be directly stored in the Brep node (internalized data of the node) and directly accessed using the combined parameters ValueList and SteamFilter.

[0054] The width W of the ang and qiao components in the column head brackets of Qing Dynasty dougong (bracket sets) is mathematically calculated to be influenced by the total number of layers (N) of the dougong starting from the first ang and qiao, and their respective layer positions (M). The variation range in Qing Dynasty official architecture is from 2 doukou (two bracket openings) starting from the first ang and qiao in the column head bracket to 4 doukou in the taojianliang (peach-point beam). Therefore, the width of the specific M layers is 2 + (2 / N) × (M-1). The ang and qiao components of the column head bracket need to be made into a separate module (Cluster) affected by the corresponding parameters, and then integrated into a subset. Due to the change in the width of the ang and qiao components, the size of the arch eyes and mortises on the horizontal brackets of the column head bracket must also change accordingly.

[0055] See Figure 5 As shown, the positions of points A and B remain unchanged, while points C and D move with the width W of the arch member. The final arch shape is obtained by connecting the moved point D and the stationary point A, and connecting the moved point C and the stationary point D, and then extruding the closed curves formed by combining lines L and R. It is used as the subtrahend in Boolean operations for calculation.

[0056] See Figure 6 As shown, when stacking arch components from bottom to top to form a digital simulation model of a dougong (bracket set), taking the Chongqiao San'ang Pingshen Ke Dougong (a type of bracket set) as an example, the components placed in the upper layer of the dougong always depend on the state of the components in the lower layer. Starting from the bottom first layer, the eighteen dougong A1 and A1' respectively calculate the points B2 and B2' of the next layer by moving two dougong openings upwards. These two points are the positions of the eighteen dougong in the second layer (layer B) with three dougong openings inwards. At the same time, B1 and B2 continue to move two dougong openings upwards to obtain the points C2 and C3 of the third layer. C3 is the position of the eighteen dougong in the third layer with six dougong openings inwards. Because a tie beam is placed on C3, the tie beam does not continue to propagate upwards.

[0057] Therefore, when designing components, there will definitely be binding points for the components. When a component is moved to a placement position, the point on the component where the upper layer component is placed will also move there. Since the pull beam no longer passes upwards, there are up to three placement points on one side of each layer. Each position can specify a component list (ValueList). You can manually select the appropriate component to quickly generate the bracket set (the method described in 4.2). In special parts such as the rear chrysanthemum head, since it does not have eighteen brackets, even if the component selection is given, the computer will not automatically place the bracket set at that location because no position is given (equivalent to the move function missing a Vector parameter).

[0058] As a preferred implementation method, when retrieving the variable style components of the corner bracket, the cross sections of the front head, rear tail and body of a single horizontal arch member are determined based on the structural parameters, and then the shape of the single horizontal arch member is generated. The structural parameters include the number of layers N of the upturned components of the corner bracket, the number of layers M of the single horizontal arch member in the corner bracket, and the number S of the single horizontal arch member from the center to the eaves.

[0059] When the number of layers N of the upturned members of the corner bracket is equal to 1, it is determined that the front head of a single transverse arch member is a grasshopper head or other members that do not protrude outwards.

[0060] When the number of layers N of the upturned members of the corner bracket is greater than 1, the number of layers N of the upturned members of the corner bracket is equal to the number of layers M of a single horizontal arch member in the corner bracket, and the number S of the single horizontal arch member from the center to the eaves is equal to the number of layers M of the single horizontal arch member in the corner bracket, the front head of the single horizontal arch member is a box arch; otherwise, the front head of the single horizontal arch member is a grasshopper head or other non-outward-projecting member.

[0061] When the number of layers N of the upturned members in the corner bracket is greater than 1, and the number of layers N of the upturned members in the corner bracket is not equal to the number of layers M of a single horizontal arch member in the corner bracket, the front head of the single horizontal arch member is either an upturned head or a upturned head.

[0062] When the number of layers N of the upturned members in the corner bracket is relative to the number of layers M of a single transverse arch in the corner bracket, and the number of layers N of the upturned members in the corner bracket is greater than 1, the cross section of a single transverse arch is a full-material arch; otherwise, it is a single-material arch.

[0063] When the number of single horizontal arch members from the center to the eaves is S = 1, the rear end is the center melon arch; when the number of single horizontal arch members from the center to the eaves is S = 2, the rear end is the center ten thousand arch; when the number of single horizontal arch members from the center to the eaves is S = 3, the rear end is the center beam.

[0064] If the number S of individual transverse arch members from the center to the overhanging eave is not equal to 1, and the number of layers N of the ang and qiao members of the corner bracket set is equal to the number of layers M of the individual transverse arch member in the corner bracket set, when the number S of individual transverse arch members from the center to the overhanging eave is equal to the number of layers M of the individual transverse arch member in the corner bracket set, the rear tail part is a xiang gong; when the difference between the number S of individual transverse arch members from the center to the overhanging eave and the number of layers M of the individual transverse arch member in the corner bracket set is 1, the rear tail part is a single cai wan gong; when the difference between the number S of individual transverse arch members from the center to the overhanging eave and the number of layers M of the individual transverse arch member in the corner bracket set is 2, the rear tail part is a zhuai fang; when the difference between the number S of individual transverse arch members from the center to the overhanging eave and the number of layers M of the individual transverse arch member in the corner bracket set is greater than 2, the rear tail part is not processed;

[0065] If the number S of individual transverse arch members from the center to the overhanging eave is not equal to 1, and the number of layers NN of the ang and qiao members of the corner bracket set is not equal to the number of layers M of the individual transverse arch member in the corner bracket set, when the number S of individual transverse arch members from the center to the overhanging eave is equal to the number of layers M of the individual transverse arch member in the corner bracket set, the rear tail part is a single cai gua gong; when the difference between the number S of individual transverse arch members from the center to the overhanging eave and the number of layers M of the individual transverse arch member in the corner bracket set is 1, the rear tail part is a single cai wan gong; when the difference between the number S of individual transverse arch members from the center to the overhanging eave and the number of layers M of the individual transverse arch member in the corner bracket set is 2, the rear tail part is a zhuai fang; when the difference between the number S of individual transverse arch members from the center to the overhanging eave and the number of layers M of the individual transverse arch member in the corner bracket set is greater than 2, the rear tail part is not processed.

[0066] The three key parameters affecting the shape of the arch member are as follows: the total number of layers N of the corner bracket set arrangement from the first ang and qiao member to the last layer, the overall layer number M of the bracket set where the arch member is located, and the sequence number S of the arch member in this layer from the center to the overhanging eave. The characteristics of the arch member at the corner determine: M≤N, S≤M, and algorithm constraints are used to avoid invalid inputs. In GrassHopper, input M and S into the MIN node, the result of the function is the smaller value of the two, if S exceeds M, the M value is returned, otherwise the S value is returned to ensure that S does not exceed M. Similarly, it is ensured that M does not exceed N.

[0067] Refer to Figure 7 as shown, this layer of bracket set is the 6th layer of bracket set upward from the large corner dou of the corner bracket set (i.e., M=6), the bracket set has a total of 6 layers upward (i.e., N=6), and the transverse arch member (M-3) is the third member of the sixth layer from the center to the overhanging eave (i.e., S=3). The front protruding head of this transverse arch member is a grasshopper head, and the rear tail part does not protrude, and is connected with the longitudinal arch member via a dovetail joint. The mortise and tenon of the blue member is exactly symmetrical along the inclined ang member, except that the mortise and tenon at the 3-3 position are overlapped with each other, the rest of the mortise and tenon are completely symmetrical.

[0068] Refer to Figure 8 , Figure 9 and Figure 10 shows the fourth member (i.e., S=4) in the direction from the center to the eave on the fifth layer (i.e., M=5) of a six-tier bracket set (i.e., N=5), which is a corner-located intersecting leading蚂蚱头 extended with a single-tier 万栱 at the rear. The members of the corner bracket set can also be divided into three regions in the manner as shown in the figure: the front protruding head (Section A), the 栱 body (Section B), and the rear tail (Section C).

[0069] The shape of the protruding ends of the corner bracket members in all directions is affected by the following rules:

[0070] (1) Front protruding head (Section A):

[0071] When N=1 (M must be equal to 1), since there is no second layer, the front protruding head is a 蚂蚱头 or other member that does not protrude outward.

[0072] When N>1 and M=N, which is the last layer of the bracket set, if S=M, the region A is a 厢栱 (left half side); if S<M, the front protruding head is a 蚂蚱头 or other member that does not protrude outward.

[0073] When N>1 and M≠N, the front protruding head is an 昂 head or a 翘 head, and the form of the protruding head is optional. At this time, no matter how the S value changes, the region A is an option for 昂 or 翘.

[0074] (2) Cross-section of the 栱 body (Section B):

[0075] Only when M=N and N>1, the cross-section of the 栱 body is a full-timber 栱, otherwise it is a single-timber 栱.

[0076] (3) Rear tail (Section C):

[0077] Determine whether S is equal to 1. If yes, the shape rule of region C is that when M=1, it connects to the central 瓜栱; when M=2, it connects to the central 万栱; when M≥3, it connects to the central 枋.

[0078] If S is not equal to 1, determine whether M is equal to N, that is, whether it is on the last layer. When M=N, the shape rule of region C is that when S=M, it connects to the 厢栱; when S=M-1, it connects to the single-timber 万栱; when S=M-2, it connects to the 拽枋; when S<M-2, the tail of the member is not processed temporarily.

[0079] If M≠N, the shape rule of region C is that when S=M, it connects to the single-timber 瓜栱; when S=M-1, it connects to the single-timber 万栱; when S=M-2, it connects to the 拽枋; when S<M-2, the tail is not processed temporarily.

[0080] After obtaining the corresponding component shapes for segments A, B, and C using the above algorithm, segment A can be moved according to the length of region B, while region B is moved according to a length of (M-1)×3. The cross-section is based on the corresponding arch cross-section, and a geometry extrusion command is executed to obtain the corresponding cuboid. The original arch shape can then be obtained using Boolean set operations.

[0081] In this embodiment, refer to Figures 11 to 13 As shown, this diagram illustrates the partitioning of mortise and tenon joints on the corner bracket set components. Taking the first mortise and tenon joint of the S-th component in layer M along the direction from the rear to the front as positioning point 1, a new positioning point is established every three bracket joints from position 1, with the last positioning point being M, forming a list L. Then, using positioning point S as the midpoint, L is divided into three parts: P is the list near the rear of the component (area C), LS is a separate section, and Q is the list near the front of the component (area A). Figure 11 For example, this is a component with N=6, M=6, S=4. The tenon and mortise openings in the Q area all face downwards, while those in the P area all face upwards. The LS point in the middle is the intersection area of ​​the slanted upturned component and the components in both the longitudinal and transverse directions.

[0082] The shape of the mortise and tenon joint of the S-th component in layer M is determined as follows:

[0083] (1) Determining the shape of the Q list (or Q region):

[0084] When M=N, if S=1, item -1 (last item) in list Q matches the tenon and mortise with the opening at the waist of the single material on both sides (tenon and mortise with the opening at the waist of the tenon and mortise), item -2 (second to last item) matches the tenon and mortise with the opening at the waist of the single material on one side and the opening at the waist of the tenon and mortise, item -3 matches the tenon and mortise with the opening at the waist of the single material on both sides, and the rest of the items less than -3 match the mortise of the dovetail tenon.

[0085] When M = N, if S ≠ 1, the -1 item in the Q list matches the tenon and mortise of the waist opening on both sides of the single material (tenon and mortise of the eighteen-dou cover), and the rest matches the tenon and mortise of the waist opening (cover) on both sides of the foot material.

[0086] When M≠N, if S=1, item -1 in the Q list matches the tenon and mortise with the bottom opening on one side of the single material and the bottom opening on the other side (the tenon and mortise of the 18-dou lid), item -2 matches the tenon and mortise with the bottom opening (lid) on one side of the single material and the bottom opening on the other side, item -3 matches the tenon and mortise with the bottom opening (lid) on both sides of the single material, and the rest of the parts smaller than M-2 match the mortise of the dovetail tenon.

[0087] When M≠N, and if S≠1, all items in the Q list match the lower opening (cover opening) notch and waist tenon of the two foot pieces.

[0088] (2) Determining the shape of the P list (or P area):

[0089] When S=1 and list P is empty, no matching occurs.

[0090] When S≠1, if M-2≤S≤M, all tenons with open notches on the main body are matched; otherwise, the first tenon is changed to a dovetail tenon, and the rest are matched with open notches on the main body.

[0091] (3) Points L to S are matched with the obliquely upturned upper opening, the width of which is determined by (1.5 + (1.3 / N) × (M-1)) and matched with the upward-facing tenon and mortise that intersects with the longitudinal arch. However, the tenon and mortise are calculated after the longitudinal arch is obtained by mirroring.

[0092] When S=M or S=1, the arch eyes on the protruding or non-protruding gable ends, melon arches, and ten-thousand arches should be set with corresponding variable parameters, because the width of the oblique gable ends will affect the shape of the arch eyes.

[0093] Furthermore, for the longitudinal members of the corner brackets and the oblique and upturned members, after the nodes of a single S member are perfected, the transverse brackets of the entire M layer are calculated separately, then moved to a designated position, and the transverse members are mirrored along the oblique and upturned members to obtain the longitudinal brackets. Except for the L~S points which need to intersect, the other tenons and mortises are completely identical. After the symmetry calculation is completed, the upper opening of the oblique and upturned tenon and mortise positions of the original members is cut with tenons, and then a Boolean difference operation is performed with the symmetry result (the open member is the cut term), so that the lower opening of the oblique and upturned position of the symmetrical member can be calculated.

[0094] The present invention provides a parametric modeling method for digital simulation models of Qing Dynasty dougong (bracket sets) based on GH (Gesture Theory). Through parametric modeling, computer parameters can be used to drive the shape of the body and column heads of Qing-style dougong, and the shape characteristics of the components can be selected to generate relevant component models. This method can not only calculate the appearance, but also determine the mortise and tenon structure that meets the installation requirements of ancient building components, provide models for virtual 3D rendering, and provide accurate digital models for CNC machine tool processing.

[0095] This invention presents a parametric modeling method for Qing Dynasty dougong (bracket sets) based on GH (Gesture Theory). This method combines the selection and automatic determination of the front and rear projection styles of specific components in a particular layer of the corner dougong, and automatically calculates the different mortise and tenon features of each component, generating a processing model. Such mortise and tenon structures meet installation requirements and avoid installation conflicts. Since each component of the corner dougong is unique, this method greatly improves the modeling efficiency of corner dougong and can match different forms of Qing Dynasty architecture.

[0096] The parametric modeling method for digital simulation model of Chinese Qing Dynasty dougong based on GH in this invention has scalability. When some dougong protrusion styles of non-official buildings in the Qing Dynasty appear, the styles can be added to the program group, thereby gradually expanding its scope of application.

[0097] This invention presents a parametric modeling method for a GH-based digital simulation model of Qing Dynasty Chinese dougong (bracket sets). By automatically performing numerous calculations within the program, the method requires very few parameters, many of which are automatically generated. This simplifies operation. Standardized components accurately represent the historical characteristics of the architecture, avoiding errors.

[0098] The above description is merely a preferred embodiment of this application and an explanation of the technical principles employed. Those skilled in the art should understand that the scope of the invention involved in this application is not limited to technical solutions formed by specific combinations of the above-described technical features, but should also cover other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the inventive concept. For example, technical solutions formed by substituting the above features with (but not limited to) technical features with similar functions disclosed in this application.

Claims

1. A parametric modeling method for a digital simulation model of Chinese Qing Dynasty dougong (bracket sets) based on GH (Gestalt Graph), characterized in that, Includes the following steps: The components of the Qing Dynasty dougong structure are divided into fixed-style components and variable-style components. The variable-style components include an arch body, a front head connected to the front end of the arch body, and a rear tail connected to the rear end of the arch body. Different shapes of the front head and the rear tail form different components. In GH software, create a set of shapes for the fixed-style components and a set of shapes for the variable-style components. The set of shapes for the variable-style components includes a subset of the arch, the front head, and the rear tail. Obtain the structural parameters of the digital simulation model of the bracket set, including the number of bracket set layers, the value of the bracket opening, the style, quantity and installation position of the components; Based on the structural parameters, retrieve the component shapes from the shape set and place them at the original point; After placing the component shape at the original point and scaling it according to the bucket opening value, the component shape at the original point is used as the subject of the Boolean operation, and the horizontal arch is used as the subtrahend of the Boolean operation to perform Boolean transport to obtain the actual shape of the vertical arch. The installation position of the horizontal arch member of the next layer is calculated and passed to the calculation node of the next layer structure to obtain the digital simulation model of the bracket set by stacking the components layer by layer from bottom to top. When the variable style component is retrieved, the variable style component is formed by splicing the shapes of the subsets of the arch body, the front head and the rear tail respectively.

2. The parametric modeling method for a digital simulation model of Qing Dynasty Chinese dougong (bracket sets) based on GH as described in claim 1, characterized in that, The subsets of the arch, the front head, and the rear tail are stored in the Brep node and retrieved through a combination of parameters ValueList and SteamFilter.

3. The parametric modeling method for a digital simulation model of Qing Dynasty Chinese dougong (bracket sets) based on GH as described in claim 1, characterized in that, When retrieving the variable style components of the corner bracket set, the cross-sections of the front head, the rear tail, and the body of a single horizontal arch member are determined based on the structural parameters, and then the shape of the single horizontal arch member is generated. The structural parameters include the number of layers of the upturned components of the corner bracket set, the number of layers of the single horizontal arch member in the corner bracket set, and the number of roots of the single horizontal arch member from the center to the eaves.

4. The parametric modeling method for a GH-based digital simulation model of Chinese Qing Dynasty dougong (bracket sets) according to claim 3, characterized in that, When the number of layers of the upturned members of the corner bracket is equal to 1, it is determined that the front head of the single transverse arch member is a grasshopper head or other members that do not protrude outwards. When the number of layers of the upturned members of the corner bracket is greater than 1, the number of layers of the upturned members of the corner bracket is equal to the number of layers of the single horizontal arch in the corner bracket, and the number of roots of the single horizontal arch from the center to the eaves is equal to the number of layers of the single horizontal arch in the corner bracket, the front head of the single horizontal arch is a box arch; otherwise, the front head of the single horizontal arch is a grasshopper head or other non-outward-projecting member. When the number of layers of the upturned members of the corner bracket is greater than 1, and the number of layers of the upturned members of the corner bracket is not equal to the number of layers of the single transverse arch member in the corner bracket, the front head of the single transverse arch member is an upturned head or an upturned head.

5. The parametric modeling method for a GH-based digital simulation model of Chinese Qing Dynasty dougong (bracket sets) according to claim 3, characterized in that, When the number of layers of the ang and qiao members of the corner bracket set is equal to the number of layers of the single transverse bracket member in the corner bracket set, and the number of layers of the ang and qiao members of the corner bracket set is greater than 1, the cross-section of the single transverse bracket member is a full-depth bracket, otherwise it is a standard-depth bracket.

6. The parametric modeling method for a digital simulation model of Qing Dynasty Chinese dougong (bracket sets) based on GH as described in claim 3, characterized in that, When the number of the single transverse bracket members from the center line to the eave overhang is equal to 1, the rear tail part is a center melon bracket; when the number of the single transverse bracket members from the center line to the eave overhang is equal to 2, the rear tail part is a center full bracket; when the number of the single transverse bracket members from the center line to the eave overhang is equal to 3, the rear tail part is a center lintel; If the number of the single transverse bracket members from the center line to the eave overhang is not equal to 1, and the number of layers of the ang and qiao members of the corner bracket set is equal to the number of layers of the single transverse bracket member in the corner bracket set, when the number of the single transverse bracket members from the center line to the eave overhang is equal to the number of layers of the single transverse bracket member in the corner bracket set, the rear tail part is an outer eave bracket; when the difference between the number of the single transverse bracket members from the center line to the eave overhang and the number of layers of the single transverse bracket member in the corner bracket set is 1, the rear tail part is a standard full bracket; when the difference between the number of the single transverse bracket members from the center line to the eave overhang and the number of layers of the single transverse bracket member in the corner bracket set is 2, the rear tail part is a dragging lintel; when the difference between the number of the single transverse bracket members from the center line to the eave overhang and the number of layers of the single transverse bracket member in the corner bracket set is greater than 2, the rear tail part is not processed; If the number of the single transverse bracket members from the center line to the eave overhang is not equal to 1, and the number N of layers of the ang and qiao members of the corner bracket set is not equal to the number of layers of the single transverse bracket member in the corner bracket set, when the number of the single transverse bracket members from the center line to the eave overhang is equal to the number of layers of the single transverse bracket member in the corner bracket set, the rear tail part is a standard melon bracket; when the difference between the number of the single transverse bracket members from the center line to the eave overhang and the number of layers of the single transverse bracket member in the corner bracket set is 1, the rear tail part is a standard full bracket; when the difference between the number of the single transverse bracket members from the center line to the eave overhang and the number of layers of the single transverse bracket member in the corner bracket set is 2, the rear tail part is a dragging lintel; when the difference between the number of the single transverse bracket members from the center line to the eave overhang and the number of layers of the single transverse bracket member in the corner bracket set is greater than 2, the rear tail part is not processed.

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