Parametric modeling method for wooden structures of official buildings in the Qing Dynasty

Abstract

The present invention discloses a parametric modeling method for the wooden structure of an official building in the Qing Dynasty. The method starts with generating column components. After each component is generated, the parameters of the component are used as the construction parameters of the next component. After the next layer of construction is completed, calculation is performed to obtain the construction parameters of the next layer of components. The construction parameters of the components layer by layer are calculated in sequence, and the final form of the components is obtained through Boolean operations. The parametric modeling of the wooden structure of an official building in the Qing Dynasty is realized by using different components to be called layer by layer and combined in different forms. The present invention relates to the field of architectural engineering technology and can solve the problems of low efficiency in creating ancient building models and lack of overall architecture parameterization in the prior art.

Description

Technical Field

[0001] The invention relates to the technical field of building engineering, and in particular to a parametric modeling method for a Qing Dynasty official-style building wooden structure. Background Art

[0002] One of the first problems that needs to be solved when using modern BIM technology to process ancient buildings is to create relevant 3D models in the computer, then use the relevant 3D models to create processing paths in the CNC programming software, and then perform physical processing. However, due to the various styles of components in ancient buildings, the complex changes in mortise and tenon joints, and the different characteristics of buildings of different categories and styles, the efficiency of using modern BIM technology to create ancient building models is relatively low.

[0003] Parametric design is a design process that writes the project itself as a function and process, and obtains the project results by modifying the initial conditions and calculating them by computer, thus realizing the automation of the design process. Some technologies related to the parametricization of ancient buildings are mainly concentrated on the components of some ancient buildings. For the parametricization of the overall structure, its degree of freedom and flexibility are greatly lacking. At present, only some components such as wing corners and brackets can be parametrically created. For the erection of components of various ancient buildings, parameterization is still not possible.

[0004] Therefore, it is necessary to provide a parametric modeling method for the wooden structure of official buildings in the Qing Dynasty, which can solve the problems of low efficiency in creating ancient building models and lack of overall structural parameterization in the prior art. Summary of the invention

[0005] The purpose of the present invention is to provide a parametric modeling method for the wooden structure of official buildings in the Qing Dynasty, which can solve the problems of low efficiency in creating ancient building models and lack of overall structural parameterization in the prior art.

[0006] The present invention is achieved in that:

[0007] A parametric modeling method for wooden structures of official buildings in the Qing Dynasty begins with generating column components. After each component is generated, the parameters of the component are used as the construction parameters of the next component. After the next layer of construction is completed, calculations are performed to obtain the construction parameters of the next layer of components. The construction parameters of the components layer by layer are calculated in turn, and the final form of the components is obtained through Boolean operations. The parametric modeling of wooden structures of official buildings in the Qing Dynasty is realized by using different components to call layer by layer and combine them in different forms.

[0008] Before the parametric modeling of the wooden structure of the official buildings of the Qing Dynasty, all the components are first classified according to categories, and each category or partial category is subdivided twice. The classification of the wooden structure of the official buildings of the Qing Dynasty includes large beams, brackets, beams, purlins, rafters, and columns. Among them, the columns are subdivided into eaves columns, gold columns, and child columns.

[0009] Nodes are created with secondary subdivided component categories. The input parameters are the construction parameters of the component itself, i.e., the A parameters, and the parameters that affect the shape of the component, i.e., the B parameters. After calculation, the relevant components and their basic models are generated. The output is the key parameters of the component itself and the components that affect the next layer.

[0010] When the component is a column, the A parameters of the input end parameters include: height, diameter, taper, side feet, rising height, placement position, rotation angle, whether it is a corner column, steamed bun tenon, and tube foot tenon; the B parameters of the input end parameters include: flat board height, large beam height, dovetail tenon shoulder, and corner column hoop tenon thickness; the key parameters of the output end that affect the components of the next layer include the column capital positioning point and the mortise and tenon size at the bottom of the large bucket.

[0011] The parametric modeling method for the official wooden structure of the Qing Dynasty comprises the following steps:

[0012] Step 1: Input the key parameters of the column to generate the column component. The original data of the column head position of the main component is used to provide the position of the beam component;

[0013] Step 2: Input the construction parameters of the beam-like components, and construct the beam-like components based on the positions of the generated beam-like components and the related parameters of the beam-like components;

[0014] Step 3: Calculate the location point of the bracket or beam based on the column head position of the column component, generate a bracket model through the bracket algorithm, and move it to the column head position to generate a bracket model at a specific position, and deduce the position of the beam;

[0015] Step 4: Combine the relationship between the bracket and the beam to generate a small beam that passes through the bracket;

[0016] Step 5: Input the key structural parameters of the beam in combination with the beam algorithm, form the beam component in combination with the beam position and the beam component generation algorithm, and generate the placement position of the purlin / child column at the same time;

[0017] Step 6: Input the key structural parameters of the purlin in combination with the purlin algorithm, and generate the purlin shape in combination with the beam shape and the purlin placement position;

[0018] Step 7: Calculate the child column / melon column components through relevant parameters such as lifting / folding;

[0019] Step 8: The position and height of the child column are used to provide the position of the next layer of beams;

[0020] Step 9: Combine the algorithm of the beam to input the key structural parameters of the next layer of beams, combine the position of the next layer of beams and the beam component generation algorithm to generate the next layer of beam components, and at the same time generate the placement position of the next layer of purlins / child columns;

[0021] Step 10: Gradually complete the erection of wooden components.

[0022] In step 2, the specific construction method of the beam-type components is as follows:

[0023] G and H are the positioning points of the bottom of the beam. The line GH passes through the center line of the bottom of the beam. The direction of the line GH is defined as the direction of the beam. The thickness of the beam is DC.

[0024] Use the input node CrossProduct to cross-product the GH direction with the Z axis direction to obtain the first coordinate axis direction V7. Use Crossproduct again to cross-product the first coordinate axis direction V7 with the GH direction to obtain the second coordinate axis direction V8.

[0025] Use the Construct Plan node, input point G at its Origin end, input the first coordinate axis direction V7 at the X-Axis end, and input the second coordinate axis direction V8 at the Y-Axis end to construct a plane, namely the third plane Plan1, which is the plane represented by GI;

[0026] Draw a cross-section wireframe 01 of the parametrically variable beam on the XY coordinate plane with Orign being (0,0,0), the first cross-section wireframe 01 being symmetrical along the Y axis of the original coordinate system, and the upper end or the lower end of the cross-section wire of the beam coincides with the X axis of the original coordinate system;

[0027] Use the Orient node, input the XY coordinate plane of the original coordinate system with Orign (0,0,0) at the Source end, the third plane Plan1 at the Target end, and the drawn first section wireframe 01 at the Geometry end;

[0028] Execute the calculation result, the drawn first section wireframe 01 is transferred to the GI plane to obtain the second section wireframe, and ensure that point G is located at the lower end of the second section wireframe. If point G is not at the lower end of the second section wireframe, flip any direction of the first coordinate axis direction V7 or the second coordinate axis direction V8 to make point G located at the lower end of the second section wireframe;

[0029] Use the CrossProduct node to cross-product the GH direction with the Z-axis direction of the original coordinate system to obtain the ninth direction V9. Use the Construct Plan node, input the ninth direction V9 at the X-Axis end, input the Z-axis direction of the original coordinate system at the Y-Axis end, and input the fourth plane Plan2 constructed at the G point position at the Origin end;

[0030] Use the ProjectAlong node, input the second section wireframe in the Geometry terminal, input the fourth plane Plan2 in the Plan terminal, and input the GH direction in the Direction terminal. That is, project the second section wireframe onto the fourth plane Plan2 along the GH direction to obtain the cross-section line of the beam that has changed due to the lifting.

[0031] Use the ExtrudeAlong node, input the cross-section line of the beam at its Base end, and input the line formed by points G and H at the Curve end. The starting point of the line is point G, and the end point is point H. Input the generated brep into the Cap Holes node to form the original shape of the beam component.

[0032] In step 3, when the beam position is deduced, the positioning algorithm in the beam body direction is as follows:

[0033] The intersection point of the corner beam and the cantilever purlin is P1, and the midpoint of the corner beam and the sub-corner beam is P2. Point P1 is obtained by calculating the first direction V1 by using CrossProduct to calculate the purlin direction and the Z-axis direction from the midpoint P0 of the cantilever purlin of the corner beam. The Move node is used to move the midpoint of the cantilever purlin by the radius of the cantilever purlin along the first direction V1 to obtain point P'. Point P' and the first direction V1 are used to define the first plane, namely Plan-A plane.

[0034] Project the old midpoint P0 of the cantilever purlin and the old midpoint P2 of the corner beam and the sub-corner beam onto the XY coordinate plane along the Z direction, and the line connecting the points becomes the second direction V2;

[0035] Use the ProjectAlong node to project the midpoint P0 of the cantilever purlin along the second direction V2 onto the Plan-A plane to obtain point P1;

[0036] Connect point P1 and point P2 to get the third direction V3. Use CrossProduct to calculate the third direction V3 and the Z direction to get the fourth direction V4. Use the Plan Normal node to define the second plane, namely the Plan-B plane, with point P2 as the original point and the fourth direction V4 as the normal direction. The Plan-B plane is the drawing plane, and the radius R is the thickness of the corner beam. Use the Cricle node to define a circle C11, which is the center of the cantilever purlin.

[0037] Use the node TangentLines, input point P1 at the Point end and point C11 at the Circle end to get two tangents Tangent1 and Tangent2; use the Midpoint node for the two tangents Tangent1 and Tangent2 to get two points PM1 and PM2; use the Largerthan node to compare the Z coordinate values ​​of points PM1 and PM2, connect point PM1 to the FirstNumber node, connect point PM2 to the SecondNumber node, input the comparison result LargerThan node to the Gate node, input Tangent1 at the 0 end and Tangent2 at the 1 end. At this time, if the Z coordinate value of point PM1 is greater than the Z coordinate value of point PM2, the LargerThan judgment result is 1, and the output result is the Tangent2 line; otherwise, the Tangent1 line is output.

[0038] In step 5, when generating the placement position of the purlin, the positioning algorithm is as follows:

[0039] The center of the cantilever purlin of the Taojian beam is point C11, and the center of the bracket is point J, which is also the force center of the Taojian beam on the bracket.

[0040] According to the overhang of the bracket and the size of the bracket mouth, the position of point C11 is obtained through the relationship of trigonometric functions: Assuming the fifth direction V5, the direction line L1 of the rafter is directly obtained through the lifting value, then use CrossProduct to input the directions of V5 and L1 to obtain the sixth direction V6, that is, the direction from point C11 to the tangent point of the cantilever purlin. Knowing that the radius of the cantilever purlin is R1, the length R1 and the sixth direction V6 are input through the Amplitude node to obtain point Q1, that is, the tangent point of the rafter on the cantilever purlin;

[0041] Draw straight line L1 along the direction of direction line L1 and tangent point Q1, use the Offset node to offset the line by the radius R2 of the center purlin to obtain straight line L2, project point J upward along the Z axis direction onto straight line L2, and the projection point is the center point C22 of the center purlin.

[0042] Compared with the prior art, the present invention has the following beneficial effects:

[0043] The present invention is based on Grasshopper programming and adopts a modular design to classify building components by category. Various components can be freely combined and each module can be assigned with an algorithm to meet various different change requirements. It can realize the rapid modeling of official buildings in the Qing Dynasty, and solves the problems of inefficient modeling of ancient buildings and lack of component parameterization in the prior art. The created model can be used for virtual display and component processing. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 It is a flow chart of the parametric modeling method of the official wooden structure of the Qing Dynasty of the present invention;

[0045] Figure 2 It is a schematic diagram of component classification in the parametric modeling method of the official wooden structure of the Qing Dynasty of the present invention;

[0046] Figure 3 This is a structural relationship diagram of a four-corner pavilion of a Qing Dynasty official wooden structure according to the present invention;

[0047] Figure 4 It is a schematic diagram of the corner beam positioning algorithm in the parametric modeling method of the official wooden structure of the Qing Dynasty of the present invention;

[0048] Figure 5 It is a schematic diagram of the positioning direction of the corner beam in the parametric modeling method of the official wooden structure of the Qing Dynasty of the present invention;

[0049] Figure 6 It is a schematic diagram of a purlin positioning algorithm in a parametric modeling method for a Qing Dynasty official-style building wooden structure of the present invention;

[0050] Figure 7 It is a schematic diagram of the beam positioning algorithm in the parametric modeling method of the official wooden structure of the Qing Dynasty of the present invention;

[0051] Figure 8 It is a schematic diagram of the first cross-section wireframe in the parametric modeling method of the official wooden structure of the Qing Dynasty of the present invention. DETAILED DESCRIPTION

[0052] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

[0053] Please see attached Figure 1 A parametric modeling method for wooden structures of official buildings in the Qing Dynasty is implemented based on Grasshopper (a visual programming language that runs on the Rhino platform). It starts with the generation of column components. After each component is generated, the parameters of the component can be used as the construction parameters of the next component. After the next layer of construction is completed, the construction parameters of the next layer of components are calculated, and the construction parameters of the components layer by layer are calculated in turn. The final form of the component is obtained through Boolean operations. By using different components to call each layer and different forms of combination, parametric modeling of wooden structures of official buildings in the Qing Dynasty is realized.

[0054] Please see attached Figure 2 Before the parametric modeling of the wooden structure of the official buildings in the Qing Dynasty, all the components are first classified according to categories. Each category or partial category can be subdivided twice. The classification of the wooden structure of the official buildings in the Qing Dynasty can include large beams, brackets, beams, purlins (purlin strips), rafters, columns (pillars), etc. Among them, the columns can be subdivided into eaves columns, gold columns, child columns, etc.

[0055] Nodes are created with secondary subdivided component categories, and the input parameters are the component's own construction parameters (defined as A parameters) and the parameters that may affect the component's shape (defined as B parameters). After calculation, the relevant components and their basic models can be generated, and the output is the key parameters of the component itself and the components that may affect the next layer.

[0056] Among them, the parameters at the output end are parameters that may affect other components and are not necessarily called by other nodes, but depend on the combination and structural form of the building.

[0057] Please see attached Figure 3 Taking the four-corner pavilion as an example, in order to adapt to the complex changes of ancient buildings, we must rely on the rules of building construction. First, the footholds of the four columns A1, A2, A3, and A4 of the ancient building are given according to the design. The four columns can be generated based on the position points of these four columns combined with the column parametric tool. After the columns are generated, the four column top points B1-B4 are calculated at the same time. Points B1-B4 are also the placement points of the four corner brackets. At the same time, the placement points of the flat brackets can be found through the relationship between points B1-B4. The positions of the purlins / purlin pads on the C1-C4 brackets can be calculated through the positions of points B1-B4. After the purlins are generated, the middle points of the four eaves purlins, namely points D1-D4, can be located as the positioning points of the corner beams. After the corner beams are located, the golden purlins and golden purlin pads E1-E4 can be located through the midpoints of the corner beams. The golden purlin positioning points and the eaves purlin positioning points can be used to position the corner beams. Points E1-E4 are calculated by lifting the frame to get point F. This process is analogous to simulating the building construction process to achieve the digital generation of the entire building.

[0058] In this way, the algorithms for specific components can be separated, such as columns or purlins, and the same algorithms can be used for other forms of ancient buildings. By establishing various parametric family libraries, the family libraries themselves carry parameters related to mortise and tenon calculations, and mortise and tenon structures can be generated. In this way, the ancient buildings to be generated can be built according to the design intention, and can adapt to the ever-changing shapes of ancient buildings.

[0059] Please see attached Figure 1 Taking the column as an example, the input end parameters A parameters include: height, diameter, taper, side foot, rise height, placement, rotation angle, whether it is a corner column, steamed bun tenon, tube foot tenon, etc. The input end parameters B parameters include: flat beam height, large beam height, dovetail tenon shoulder, corner column hoop tenon thickness, etc. The key parameters of the output end that may affect the next layer of components include the column head positioning point, the mortise and tenon size at the bottom of the large bucket, etc.

[0060] When performing parametric modeling of the wooden structure of official Qing Dynasty buildings, each component is designed to generate its corresponding shape independently as much as possible without relying on Boolean operations with other components, thus avoiding cross-references of component model operation results.

[0061] Please see attached Figure 1 Specifically, the parametric modeling method for the official wooden structure of the Qing Dynasty includes the following steps:

[0062] Step 1: Input the key parameters of the column to generate the column component. The original data of the column head position of the main component can provide the position of the flat beam / front beam / small front beam / queti and other beam components.

[0063] Step 2: Input the construction parameters of the beam-like components, and construct the beam-like components based on the positions of the generated beam-like components and the related parameters of the beam-like components.

[0064] Please see attached Figure 7 The specific construction method of beam components is as follows:

[0065] In ancient buildings, there may be a "raised" structure, that is, a beam is not on the same horizontal plane, that is, one side is high and the other side is low. Figure 7 As shown, G and H are the positioning points at the bottom of the beam, and the line GH passes through the center line of the bottom of the beam. The direction of the line GH is defined as the direction of the beam, and the thickness of the beam is DC length.

[0066] Use the input node CrossProduct to cross-product the GH direction with the Z axis direction to obtain the first coordinate axis direction V7, and use Crossproduct again to cross-product the first coordinate axis direction V7 with the GH direction to obtain the second coordinate axis direction V8.

[0067] Use the Construct Plan node, input point G at its Origin end, input the first coordinate axis direction V7 at the X-Axis end, and input the second coordinate axis direction V8 at the Y-Axis end to construct a plane, namely the third plane Plan1, which is the plane represented by GI.

[0068] A cross-section wireframe 01 of a parametric beam is drawn on an XY coordinate plane with Orign being (0,0,0). The first cross-section wireframe 01 is symmetrical along the Y axis of the original coordinate system, and the upper or lower end of the cross-section wireframe of the beam coincides with the X axis of the original coordinate system.

[0069] Use the Orient node, input the XY coordinate plane of the original coordinate system with Orign (0,0,0) at the Source end, the third plane Plan1 at the Target end, and the first section wireframe 01 at the Geometry end, as shown in the attached figure. Figure 8 shown.

[0070] After executing the calculation results, the drawn first section wireframe 01 is transferred to the GI plane to obtain the second section wireframe, ensuring that point G is located at the lower end of the second section wireframe. If point G is not at the lower end of the second section wireframe, flip any direction of the first coordinate axis direction V7 or the second coordinate axis direction V8 to make point G located at the lower end of the second section wireframe.

[0071] Use the CrossProduct node to cross-product the GH direction with the Z-axis direction of the original coordinate system to obtain the ninth direction V9. Use the Construct Plan node, input the ninth direction V9 at its X-Axis end, input the Z-axis direction of the original coordinate system at its Y-Axis end, and input the fourth plane Plan2 constructed at the G point position at its Origin end.

[0072] Use the ProjectAlong node, input the second section wireframe in the Geometry terminal, input the fourth plane Plan2 in the Plan terminal, and input the GH direction in the Direction terminal. That is, project the second section wireframe onto the fourth plane Plan2 along the GH direction to obtain the cross-section line of the beam that has changed due to the lifting.

[0073] Use the ExtrudeAlong node, input the cross-section line of the beam at its Base end, and input the line formed by points G and H at the Curve end. The starting point of the line is point G, and the end point is point H. Input the generated brep into the Cap Holes node to form the original shape of the beam component.

[0074] This method ensures that the beam can be accurately shaped according to the cross-sectional dimensions and corresponding rise requirements required by the design. It can be applied to the calculation of various types of beams, including buildings with rises. The above method can also be used to obtain the precise original shape of beam components.

[0075] The beam components are connected to columns by dovetail joints, straight joints, and through joints, and may have different shapes when connected to round or square columns. Different calculation results are stored using the Gate node, and then ValueList is used to access the Gate end of the Steamfilter node for combined calls, so as to match different column positions and different mortise and tenon joints.

[0076] Step 3: Calculate the positioning point of the bracket or beam based on the column head position of the column component, generate a bracket model through the bracket algorithm, and move it to the column head position to generate a bracket model at a specific position, and deduce the position of the beam.

[0077] The components such as the overlord coupons of the lintels, the hemp leaf clouds, the raised heads, and the six-point heads of the brackets are directly modeled according to the 1mm bracket mouth value, and then stored in brep. When it is necessary to generate related shapes, you can directly call the nodes and enlarge them according to the proportion, which can save parametric creation efficiency.

[0078] Please see attached Figure 4 and attached Figure 5 When deriving the position of the beam, taking the corner beam as an example, the positioning algorithm in the beam body direction is as follows:

[0079] The intersection point of the corner beam and the cantilever purlin is P1, and the midpoint of the corner beam and the sub-corner beam is P2. Point P1 is calculated by using CrossProduct to calculate the first direction V1 by the midpoint of the cantilever purlin of the corner beam (P0) (i.e. the center point of the cantilever purlin at the intersection of the purlin corners) and the direction of the purlin (the original coordinate system is established with the X-axis, Y-axis and Z-axis). The Move node is used to move the midpoint of the cantilever purlin by the distance of the cantilever purlin radius along the first direction V1 to obtain point P'. Point P' and the first direction V1 are used to define the first plane, namely the Plan-A plane.

[0080] Project the old midpoint P0 of the cantilever purlin and the old midpoint P2 of the corner beam and the sub-corner beam onto the XY coordinate plane along the Z direction, and the line connecting the obtained points becomes the second direction V2.

[0081] Use the ProjectAlong node to project the midpoint P0 of the cantilever purlin along the second direction V2 onto the Plan-A plane to obtain point P1.

[0082] Connect point P1 and point P2 to get the third direction V3. Use CrossProduct to calculate the third direction V3 and the Z direction to get the fourth direction V4. Use the Plan Normal node to define the second plane, namely the Plan-B plane, with point P2 as the original point and the fourth direction V4 as the normal direction. The Plan-B plane is the drawing plane, and the radius R is the thickness of the corner beam. Use the Cricle node to define a circle C11, which is the center of the cantilever purlin.

[0083] Use the node TangentLines, Point to input point P1, and Circle to input point C11, and you can get two tangents Tangent1 and Tangent2. Use the Midpoint node for the two tangents Tangent1 and Tangent2 to get two points PM1 and PM2. Use the Largerthan node to compare the Z coordinate values ​​of points PM1 and PM2. Point PM1 is connected to the FirstNumber node, and point PM2 is connected to the SecondNumber node. Input the comparison result LargerThan node to the Gate node, input Tangent1 to the 0 end, and Tangent2 to the 1 end. At this time, if the Z coordinate value of point PM1 is greater than the Z coordinate value of point PM2, the LargerThan judgment result is 1, and the output result is the Tangent2 line; otherwise, the Tangent1 line is output. This ensures that no matter what the random result output is, the line at the bottom of the angle beam, that is, the direction of the beam body, can be automatically selected.

[0084] As above, the spatial position of the corner beam and the precise direction of the beam can be calculated by the position of the purlin and the thickness of the corner beam. By generating corner beams parametrically, the corner beam shape that matches the wooden frame can be quickly generated, a processing model can be provided, and the direction of the corner beam can be automatically determined.

[0085] Step 4: Combine the relationship between the bracket and the beam to generate a small beam that passes through the bracket.

[0086] Step 5: Input the key structural parameters of the beam in combination with the beam algorithm, form the beam component in combination with the beam position and the beam component generation algorithm, and generate the placement position of the purlin / child column at the same time.

[0087] Please see attached Figure 6 When generating the placement position of the purlin, the positioning algorithm is as follows:

[0088] In the official buildings of the Qing Dynasty, the roof rise is the key parameter for defining the pitched roof, which determines the direction of the rafters erected between two purlins. If the direction of the rafters is strictly determined according to the rise parameter, after determining the height position of the lower purlin, the position of the upper purlin can be obtained by the rise value. This ensures that the direction of the roof rafters can strictly reflect the rise ratio.

[0089] The center of the cantilever purlin of the peach-pointed beam is point C11, and the center position of the bracket is point J, which is also the force center of the peach-pointed beam on the bracket.

[0090] First, according to the projection of the bracket and the size of the bracket mouth, the position of point C11 is obtained through the relationship between trigonometric functions: Assuming that it is perpendicular to Figure 6The direction of the plane shown is the fifth direction V5. The direction line L1 of the rafter can be directly obtained through the lifting value. Then, CrossProduct can be used to input the directions of V5 and L1 to obtain the sixth direction V6, which is the direction from point C11 to the tangent point of the cantilever purlin. The radius of the cantilever purlin is known to be R1. Then, the length R1 and the sixth direction V6 can be input through the Amplitude node to obtain point Q1, which is the tangent point of the rafter on the cantilever purlin.

[0091] Draw straight line L1 along the direction of direction line L1 and tangent point Q1. Use the Offset node to offset the line by the radius R2 of the center purlin to obtain straight line L2. Project point J upward along the Z axis direction onto straight line L2. The projection point is the center point C22 of the center purlin.

[0092] Similarly, the contact point between the center purlin and the center beam can be calculated through the trigonometric function relationship, and then the height of the last layer of the center beam can be obtained.

[0093] According to this method, the position of the purlin can be calculated parameterized by the lifting parameters of all roofs. The position of the upper purlin can be automatically calculated through the lifting and stepping frames, the diameter of each purlin and the position of the lower purlin, which can be used to directly locate the purlin position, and then the height of the lower supporting member can be inferred through the positioning of the purlin. Similarly, in the calculation of three-beam, five-beam, seven-beam or nine-beam components, the height of the melon column on the beam frame can also be calculated by the above method.

[0094] Step 6: Input the key construction parameters of the purlin in combination with the purlin algorithm, and generate the purlin shape in combination with the beam shape and the purlin placement.

[0095] Step 7: Calculate the child column / melon column components through relevant parameters such as lifting / folding.

[0096] Step 8: The position and height of the child column are used to provide the position of the next layer of beams.

[0097] Step 9: Input the key construction parameters of the next layer of beams in combination with the beam algorithm, generate the next layer of beam components in combination with the position of the next layer of beams and the beam component generation algorithm, and generate the placement positions of the next layer of purlins / columns.

[0098] Step 10: Gradually complete the erection of wooden components.

[0099] The present invention divides the ancient buildings into component categories, and for some components whose variation range can be included in the parameter range, a set of parametric generation nodes is summarized, which allows the input of structure and other parameters, and can generate the position and other parameters that affect other components. Through the free combination of different nodes, the wooden structure model of the official building of the Qing Dynasty in the design intention can be created, and the deepening of the mortise and tenon structure is completed, and the erection of wooden components is gradually completed.

[0100] The above are only preferred embodiments of the present invention and are not intended to limit the scope of protection of the invention. Therefore, any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A parametric modeling method for wooden structures of official buildings in the Qing Dynasty, characterized by: Starting from the generation of column components, after each component is generated, the parameters of the component are used as the construction parameters of the next component; after the next layer of construction is completed, the construction parameters of the next layer of components are calculated, and the construction parameters of each layer of components are calculated in turn, and the final form of the component is obtained through Boolean operations; by using different components to call each layer and combine them in different forms, the parametric modeling of the wooden structure of the official building of the Qing Dynasty is realized; The parametric modeling method for the official wooden structure of the Qing Dynasty comprises the following steps: Step 1: Input the key parameters of the column to generate the column component. The original data of the column head position of the main component is used to provide the position of the beam component; Step 2: Input the construction parameters of the beam-like components, and construct the beam-like components based on the positions of the generated beam-like components and the related parameters of the beam-like components; Step 3: Calculate the location point of the bracket or beam based on the column head position of the column component, generate a bracket model through the bracket algorithm, and move it to the column head position to generate a bracket model at a specific position, and deduce the position of the beam; Step 4: Combine the relationship between the bracket and the beam to generate a small beam that passes through the bracket; Step 5: Input the key structural parameters of the beam in combination with the beam algorithm, form the beam component in combination with the beam position and the beam component generation algorithm, and generate the placement position of the purlin / child column at the same time; Step 6: Input the key structural parameters of the purlin in combination with the purlin algorithm, and generate the purlin shape in combination with the beam shape and the purlin placement position; Step 7: Calculate the child column / melon column components through the lifting / folding related parameters; Step 8: The position and height of the child column are used to provide the position of the next layer of beams; Step 9: Combine the algorithm of the beam to input the key structural parameters of the next layer of beams, combine the position of the next layer of beams and the beam component generation algorithm to generate the next layer of beam components, and at the same time generate the placement position of the next layer of purlins / child columns; Step 10: gradually complete the installation of wooden components; In step 2, the specific construction method of the beam-type components is as follows: G and H are the positioning points of the bottom of the beam. The line GH passes through the center line of the bottom of the beam. The direction of the line GH is defined as the direction of the beam. The thickness of the beam is DC. Use the input node CrossProduct to cross-product the GH direction with the Z axis direction to obtain the first coordinate axis direction V7. Use Crossproduct again to cross-product the first coordinate axis direction V7 with the GH direction to obtain the second coordinate axis direction V8. Use the Construct Plan node, input point G at its Origin end, input the first coordinate axis direction V7 at the X-Axis end, and input the second coordinate axis direction V8 at the Y-Axis end to construct a plane, namely the third plane Plan1, which is the plane represented by GI; Draw a cross-section wireframe 01 of the parametrically variable beam on the XY coordinate plane with Orign being (0,0,0), the first cross-section wireframe 01 being symmetrical along the Y axis of the original coordinate system, and the upper end or the lower end of the cross-section wire of the beam coincides with the X axis of the original coordinate system; Use the Orient node, input the XY coordinate plane of the original coordinate system with Orign (0,0,0) at the Source end, the third plane Plan1 at the Target end, and the drawn first section wireframe 01 at the Geometry end; Execute the calculation result, the drawn first section wireframe 01 is transferred to the GI plane to obtain the second section wireframe, and ensure that point G is located at the lower end of the second section wireframe. If point G is not at the lower end of the second section wireframe, flip any direction of the first coordinate axis direction V7 or the second coordinate axis direction V8 to make point G located at the lower end of the second section wireframe; Use the CrossProduct node to cross-product the GH direction with the Z-axis direction of the original coordinate system to obtain the ninth direction V9. Use the Construct Plan node, input the ninth direction V9 at the X-Axis end, input the Z-axis direction of the original coordinate system at the Y-Axis end, and input the fourth plane Plan2 constructed at the G point position at the Origin end; Use the ProjectAlong node, input the second section wireframe in the Geometry terminal, input the fourth plane Plan2 in the Plan terminal, and input the GH direction in the Direction terminal. That is, project the second section wireframe onto the fourth plane Plan2 along the GH direction to obtain the cross-section line of the beam that has changed due to the lifting. Use the ExtrudeAlong node, input the cross-section line of the beam at its Base end, and input the line formed by points G and H at the Curve end. The starting point of the line is point G, and the end point is point H. Input the generated brep into the Cap Holes node to form the original shape of the beam component. In step 3, when the beam position is deduced, the positioning algorithm in the beam body direction is as follows: The intersection point of the corner beam and the cantilever purlin is P1, and the midpoint of the corner beam and the sub-corner beam is P2. Point P1 is obtained by calculating the first direction V1 by using CrossProduct to calculate the purlin direction and the Z-axis direction from the midpoint P0 of the cantilever purlin of the corner beam. The Move node is used to move the midpoint of the cantilever purlin by the radius of the cantilever purlin along the first direction V1 to obtain point P'. Point P' and the first direction V1 are used to define the first plane, namely Plan-A plane. Project the old midpoint P0 of the cantilever purlin and the old midpoint P2 of the corner beam and the sub-corner beam onto the XY coordinate plane along the Z direction, and the line connecting the points becomes the second direction V2; Use the ProjectAlong node to project the midpoint P0 of the cantilever purlin along the second direction V2 onto the Plan-A plane to obtain point P1; Connect point P1 and point P2 to get the third direction V3. Use CrossProduct to calculate the third direction V3 and the Z direction to get the fourth direction V4. Use the Plan Normal node to define the second plane, namely the Plan-B plane, with point P2 as the original point and the fourth direction V4 as the normal direction. The Plan-B plane is the drawing plane, and the radius R is the thickness of the corner beam. Use the Cricle node to define a circle C11, which is the center of the cantilever purlin. Use the node TangentLines, input point P1 at the Point end and point C11 at the Circle end to get two tangents Tangent1 and Tangent2; use the Midpoint node for the two tangents Tangent1 and Tangent2 to get two points PM1 and PM2; use the Largerthan node to compare the Z coordinate values ​​of PM1 and PM2, connect PM1 to the FirstNumber node, connect PM2 to the SecondNumber node, input the comparison result LargerThan node to the Gate node, input Tangent1 at the 0 end and Tangent2 at the 1 end. At this time, if the Z coordinate value of PM1 is greater than the Z coordinate value of PM2, the LargerThan judgment result is 1, and the output result is the Tangent2 line; otherwise, the Tangent1 line is output; In step 5, when generating the placement position of the purlin, the positioning algorithm is as follows: The center of the cantilever purlin of the Taojian beam is point C11, and the center of the bracket is point J, which is also the force center of the Taojian beam on the bracket. According to the overhang of the bracket and the size of the bracket mouth, the position of point C11 is obtained through the relationship of trigonometric functions: Assuming the fifth direction V5, the direction line L1 of the rafter is directly obtained through the lifting value, then use CrossProduct to input the directions of V5 and L1 to obtain the sixth direction V6, that is, the direction from point C11 to the tangent point of the cantilever purlin. Knowing that the radius of the cantilever purlin is R1, the length R1 and the sixth direction V6 are input through the Amplitude node to obtain point Q1, that is, the tangent point of the rafter on the cantilever purlin; Draw straight line L1 along the direction of direction line L1 and tangent point Q1, use the Offset node to offset the line by the radius R2 of the center purlin to obtain straight line L2, project point J upward along the Z axis direction onto straight line L2, and the projection point is the center point C22 of the center purlin.

2. The parametric modeling method for official wooden structures of Qing Dynasty according to claim 1 is characterized in that: Before the parametric modeling of the wooden structure of the official buildings of the Qing Dynasty, all the components are first classified according to categories, and each category or partial category is subdivided twice. The classification of the wooden structure of the official buildings of the Qing Dynasty includes large beams, brackets, beams, purlins, rafters, and columns, among which the columns are subdivided twice into eaves columns, gold columns, and child columns.

3. The parametric modeling method for the official wooden structure of the Qing Dynasty according to claim 2 is characterized by: Nodes are created with secondary subdivided component categories. The input parameters are the construction parameters of the component itself, i.e., the A parameters, and the parameters that affect the shape of the component, i.e., the B parameters. After calculation, the relevant components and their basic models are generated. The output is the key parameters of the component itself and the components that affect the next layer.

4. The parametric modeling method for the official wooden structure of the Qing Dynasty according to claim 3 is characterized by: When the component is a column, the A parameters of the input end parameters include: height, diameter, taper, side feet, rising height, placement position, rotation angle, whether it is a corner column, steamed bun tenon, and tube foot tenon; the B parameters of the input end parameters include: flat board height, large beam height, dovetail tenon shoulder, and corner column hoop tenon thickness; the key parameters of the output end that affect the components of the next layer include the column capital positioning point and the mortise and tenon size at the bottom of the large bucket.

Images