Geometric data management and rendering method for full-parametric steel structure modeling

Abstract

The invention belongs to the technical field of building modeling, and particularly relates to geometric data management of full-parameterized steel structure modeling, and the technical scheme is that the geometric data management of full-parameterized steel structure modeling comprises the following steps: dividing visual entity objects related to steel structure construction into the following categories: beams, curved beams, zigzag beams, plates, bolts and welding seams; except for the welding seam, other objects are managed and drawn in a unified mode through the method; and other vertexes which do not fall on the central plane are expanded, and a quick feature value extraction rule aiming at the geometric data of the part appearance is provided by combining the business characteristics of the steel structure modeling field: the feature value extraction speed is high, the generated feature value is simple and short, the indexing efficiency is high, and the same geometric data must correspond to the same feature value.

Description

Technical Field

[0001] The present invention belongs to the technical field of building modeling, and specifically refers to a method for geometric data management and rendering of fully parametric steel structure modeling. Background Art

[0002] For large-scale 3D CAD systems for steel structure construction, they need to process large-scale 3D scenes. For a medium-scale steel structure building with a volume of 7,000 tons, the number of parts and detailed objects usually exceeds several hundred thousand. Therefore, how to smoothly draw and edit large-scale 3D scenes has become an important challenge in the research and development of related CAD systems. Summary of the Invention

[0003] To solve the problem that for large-scale 3D CAD systems for steel structure construction currently, they need to process large-scale 3D scenes. For a medium-scale steel structure building with a volume of 7,000 tons, the number of parts and detailed objects usually exceeds several hundred thousand, and how to smoothly draw and edit large-scale 3D scenes has become an important challenge in the research and development of related CAD systems, the present invention proposes a geometric data management applicable to fully parametric steel structure modeling.

[0004] The technical solution adopted by the present invention is as follows: The present invention provides a geometric data management for fully parametric steel structure modeling, and divides the entity objects related to visualization in steel structure construction into the following categories: beams, curved beams, folded beams, plates, bolts, welds; except for welds, other objects are uniformly managed and drawn through the method described in this article.

[0005] Further, for beam parts, the attribute objects affecting their visualization are abstracted as follows:

[0006] Type: steel / concrete;

[0007] Rendering quality;

[0008] Section profile;

[0009] Eccentric direction;

[0010] Eccentricity;

[0011] Rotation reference t;

[0012] Rotation angle;

[0013] Twisted head and tail angle;

[0014] Beam length.

[0015] Further, for curved beam parts, the attribute objects affecting their visualization are abstracted as follows:

[0016] Type: steel / concrete;

[0017] Rendering quality;

[0018] Section profile

[0019] Bending plane

[0020] Bending radius

[0021] Eccentric direction

[0022] Eccentricity

[0023] Rotation reference

[0024] Rotation angle

[0025] Twisting head and tail angle

[0026] Beam length

[0027] Furthermore, for the folded beam part, the property objects that affect its visualization are abstracted as follows:

[0028] Type: steel / concrete

[0029] Rendering quality

[0030] Section profile

[0031] Local coordinate sequence of turning points

[0032] Eccentric direction

[0033] Eccentricity

[0034] Rotation reference

[0035] Rotation angle

[0036] Twisting head and tail angle

[0037] Beam length

[0038] Furthermore, for the plate part, the property objects that affect its visualization are abstracted as follows:

[0039] Type: steel / concrete

[0040] Plate thickness

[0041] Directed sequence of local coordinates of plate corner points

[0042] Furthermore, for the bolt details, the property objects that affect its visualization are abstracted as follows: Screw type: hexagon, shear stud, chemical anchor bolt

[0043] Screw length

[0044] Screw name

[0045] Sequence of gasket names

[0046] Nut name sequence;

[0047] Depth of part hole.

[0048] Furthermore, the present invention also provides a rendering method for geometric data management in full-parametric steel structure modeling, including the following steps:

[0049] Step 1: Surface cutting, taking the quaternion parameters of the cutting plane as its characteristic attributes; geometric entity cutting, according to the type of the cutting entity, classifying it into the corresponding ordinary parts to extract characteristic attributes;

[0050] Step 2: Abstract it into a unique string index code. For part objects with the same appearance, their index codes are the same;

[0051] Step 3: Based on the above parametric characteristic values, a geometric data management system with part characteristic values as the unique index is established;

[0052] Step 4: In addition to geometric data, each part object also has instance-specific data such as spatial position. This part of the data cannot be indexed and contracted through characteristic values. The actual drawing data of each part object is divided into two parts;

[0053] Step 5: For instance data with the same geometric data, before drawing, write it into a unified data buffer. During the drawing process, use instance rendering technology to complete the drawing of all parts with the same geometric data with only one drawing instruction;

[0054] Step 6: For each instance unit area, we assign it one of three states: 0: unused 1: modified 2: maintained;

[0055] For example, if an instance unit area has not been used by any object since the last drawing, it is marked as unused; if an instance unit area needs to be used in this drawing but the data does not need to be modified, it is marked as maintained;

[0056] For example, if an instance unit area needs to be used in this drawing but the data has been modified, it is marked as modified;

[0057] When all instance units are assigned the correct marks, we will check all the marked areas to be modified and preferentially fill them into the unused marked areas before the maintained areas, so as to minimize the modification range of the entire buffer and further reduce the real-time communication volume between the CPU and the GPU.

[0058] The beneficial effects achieved by the present invention with the above structure are as follows:

[0059] 1. Combining the business characteristics of the steel structure modeling field, a fast eigenvalue extraction rule for the geometric data of part appearance is proposed: the eigenvalue extraction speed is fast, the generated eigenvalues are concise and small, the indexing efficiency is high, and the same geometric data must correspond to the same eigenvalue.

[0060] 2. A loop-nested index format is designed, which can be applied to the eigenvalue extraction and indexing of geometric data in complex situations such as secondary part processing in large-scale modeling, greatly increasing the reuse efficiency and application scope of geometric data indexing.

[0061] 3. Based on the reuse of part geometric data and the buffer marking management of instance data, a high-efficiency instance rendering architecture method is designed. BRIEF DESCRIPTION OF THE DRAWINGS

[0062] Figure 1 is a flowchart of nestable parametric eigenvalues;

[0063] Figure 2 is a rendering process for batch objects Figure 1 ;

[0064] Figure 3 is a rendering process for batch objects Figure 2 ;

[0065] Figure 4 is a rendering process for batch objects Figure 3 ;

[0066] The drawings are used to provide a further understanding of the present invention, and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention, and do not constitute a limitation to the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0067] The following are specific embodiments of the present invention, which further describe the technical solutions of the present invention, but the protection scope of the present invention is not limited to these embodiments. Any changes or equivalent substitutions that do not deviate from the concept of the present invention are included in the protection scope of the present invention.

[0068] Embodiment 1

[0069] This embodiment is a three-dimensional modeling system for urban information based on big data, which divides the visualized entity objects involved in steel structure construction into the following categories:

[0070] Beams, curved beams, folded beams, plates, bolts, welds;

[0071] Except for welds, other objects are uniformly managed and drawn by the method described in this article.

[0072] Embodiment 2

[0073] This embodiment is a rendering method for geometric data management in fully parametric steel structure modeling, including the following steps:

[0074] Step 1: Surface cutting, taking the quaternion parameters of the cutting plane as its characteristic attributes; geometric entity cutting, classifying the cutting entities into corresponding ordinary parts according to their types and extracting characteristic attributes;

[0075] Step 2: Abstract it into a unique string index code. Parts objects with the same appearance have the same index code;

[0076] Step 3: Based on the above parametric characteristic values, a geometric data management system with part characteristic values as the unique index is established;

[0077] Step 4: In addition to geometric data, each parts object also has instance-specific data such as spatial position. This part of the data cannot be indexed and contracted through characteristic values. The actual drawing data of each parts object is divided into two parts;

[0078] Step 5: For instance data with the same geometric data, before drawing, write it into a unified data buffer. During the drawing process, use instance rendering technology to complete the drawing of all parts with the same geometric data with only one drawing instruction;

[0079] Step 6: For each instance unit area, we assign it one of three states: 0: unused; 1: modified; 2: maintained;

[0080] For example, if an instance unit area has not been used by any object since the last drawing, it is marked as unused; if an instance unit area needs to be used in this drawing but does not need to modify the data, it is marked as maintained;

[0081] For example, if an instance unit area needs to be used in this drawing but the data has been modified, it is marked as modified;

[0082] When all instance units are assigned the correct marks, we will check all the marked areas to be modified and preferentially fill them into the unused marked areas before the maintained areas, so as to minimize the modification range of the entire buffer and thus reduce the real-time communication volume between the CPU and the GPU.

[0083] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be obvious to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to these embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. Geometric data management for fully parametric steel structure modeling, characterized in that: The entity objects related to the visualization of steel structure construction are classified into the following categories: Beams, curved beams, folded beams, plates, bolts, welds; Except for welds, other objects are uniformly managed and drawn by the method described in this article.

2. The geometric data management of a fully parametric steel structure modeling according to claim 1, characterized in that: For beam parts, the attribute objects affecting their visualization are abstracted as follows: Type: steel / concrete; Rendering quality; Section profile; Eccentric direction; Eccentricity; Rotation reference t; Rotation angle; Twisted head and tail angle; Beam length.

3. The geometric data management of a fully parametric steel structure modeling according to claim 2, characterized in that: For curved beam parts, the attribute objects affecting their visualization are abstracted as follows: Type: steel / concrete; Rendering quality; Section profile; Bending plane; Bending radius; Eccentric direction; Eccentricity; Rotation reference; Rotation angle; Twisted head and tail angle; Beam length.

4. The geometric data management of a fully parametric steel structure modeling according to claim 3, characterized in that: For folded beam parts, the attribute objects affecting their visualization are abstracted as follows: Type: steel / concrete; Rendering quality; Section profile; Local coordinate sequence of turning points; Eccentric direction; Eccentricity; Rotation reference; Rotation angle; Twisted head and tail angle; Beam length.

5. The geometric data management of a fully parametric steel structure modeling according to claim 4, characterized in that: For plate parts, the attribute objects affecting their visualization are abstracted as follows: Type: steel / concrete; Plate thickness; Directed sequence of local coordinates of plate corner points.

6. The geometric data management of a fully parametric steel structure modeling according to claim 5, characterized in that: For bolt details, the attribute objects affecting their visualization are abstracted as follows: Screw type: hexagon, shear stud, chemical bolt; Screw length; Screw name; Sequence of gasket names; Sequence of nut names; Depth of part hole.

7. A rendering method for geometric data management in fully parametric steel structure modeling according to claim 6, characterized in that: Including the following steps: Step 1: Surface cutting, taking the quaternion parameters of the cutting plane as its characteristic attributes; geometric entity cutting, according to the type of the cutting entity, classifying it into the corresponding ordinary parts to extract characteristic attributes; Step 2: Abstracted as a unique string index code, for part objects with the same appearance, their index codes are the same; Step 3: Based on the above parameterized characteristic values, a geometric data management system with part characteristic values as the unique index is established; Step 4: In addition to geometric data, each part object also has instance-specific data such as spatial position, and this part of the data cannot be indexed and contracted through characteristic values. The actual drawing data of each part object is divided into two parts; Step 5: For instance data with the same geometric data, before drawing, write it into a unified data buffer. During the drawing process, use instance rendering technology to complete the drawing of all parts with the same geometric data with only one drawing instruction; Step 6: For each instance unit area, we assign it one of three states: 0: unused 1: modified 2: kept; For example, if an instance unit area has not been used by any object since the last drawing, it is marked as unused; if an instance unit area needs to be used in this drawing but the data does not need to be modified, it is marked as kept; For example, if an instance unit area needs to be used in this drawing but the data has been modified, it is marked as modified; When all instance units are assigned the correct marks, we will check all the marked areas to be modified and preferentially fill them into the unused marked areas before the kept areas, so as to minimize the modification range of the entire buffer and further reduce the real-time communication volume between the CPU and the GPU ends.

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