Intersection judgment method suitable for intensive city scene ray tracing technology

Abstract

The invention discloses an intersection judgment method suitable for a dense city scene ray tracing technology. The intersection judgment method comprises the following steps: emitting a plurality of ray beams by taking an emission point as a source point; selecting a ray beam, and constructing a support function of a polygon on the bottom surface; constructing a support direction for the polygon in the scene, and constructing a support angle for the polygon on the bottom surface of the ray beam; calculating supporting points of the polygon in the scene according to the supporting direction, calculating supporting points of the polygon on the bottom surface of the ray beam by using the supporting angle, and calculating a new vertex by using the two supporting points; constructing an intersection judgment triangle according to the new vertex, and judging whether the polygon in the scene is intersected with the polygon on the bottom surface of the ray beam according to the position relationship between the intersection judgment triangle and the original point; for a polygon in a scene intersected with a polygon on the bottom surface of a ray beam, a new ray beam is generated by using a mirror reflection principle, and channel information in the scene is calculated by covering information of the ray beam of a receiving point. The method meets the requirement of the ray tracing technology for efficient and accurate polygon intersection judgment.

Description

Technical Field

[0001] The invention relates to an intersection determination method applicable to ray tracing technology for dense urban scenes, and belongs to the technical field of wireless communication. Background Art

[0002] In the field of wireless communications, channel modeling is a basic tool for the design, optimization and evaluation of wireless communication systems. Ray tracing technology, as a deterministic channel modeling method, analyzes the propagation characteristics of radio waves based on geometric optics and consistent diffraction theory. The channel model is highly accurate after calibration with measured data. According to different implementation methods, ray tracing methods can be roughly divided into two types, the Shooting and Bouncing Ray Method (SBR) and the Image Method (IM). Among them, the ray bouncing method has a faster simulation speed but lower accuracy than the image method. The image method has higher accuracy but slower simulation speed than the ray bouncing method. In complex scenes, the simulation time of the image method will increase exponentially according to the number of objects in the scene. Therefore, the image method is relatively unsuitable for urban scenes with large areas and many objects.

[0003] In relatively complex and dense urban communication scenarios, the ray bouncing method is more widely used. The ray bouncing method uniformly launches tens of thousands of rays at the transmitter, and these rays propagate in the scene until the number of interactions such as reflection or diffraction reaches a preset order. By determining the rays reaching the receiver and calculating their ray paths, the multipath information of the transmitter and the receiver can be accurately calculated. Using information such as the power, delay, and angle of these multipaths, accurate channel characteristics can be calculated. Polygon intersection determination is a key factor in determining the efficiency and accuracy of ray tracing channel model simulation, and often accounts for more than 90% of the simulation time. The intersection determination algorithm in the existing ray tracing channel model has a lot of redundancy and limited accuracy, which restricts the development of high-performance ray tracing technology.

[0004] Although polygon intersection determination technology has made significant progress, with the continuous increase in application requirements, existing technologies still have limitations in computational complexity, memory consumption, accuracy and applicability. When dealing with complex polygons, traditional intersection determination algorithms have high computational complexity and are difficult to meet real-time requirements; when dealing with large-scale polygon data, existing algorithms often require a large amount of memory, affecting the performance and stability of the system; in some high-precision application scenarios, the accuracy of existing algorithms is insufficient, resulting in a high misjudgment rate that affects the reliability of the results; existing technologies lack versatility in dealing with specific types of polygons. Therefore, there is an urgent need for an efficient, accurate and universal polygon intersection determination method to address the shortcomings of existing technologies and meet the urgent needs of various fields for polygon intersection determination technology. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide an intersection determination method suitable for ray tracing technology in dense urban scenes, simplify the polygon intersection problem by using support functions, calculate vertices through support functions to quickly determine whether polygons intersect, and meet the needs of ray tracing technology in dense urban scenes for efficient and accurate polygon intersection determination.

[0006] The present invention adopts the following technical solutions to solve the above technical problems:

[0007] An intersection determination method applicable to ray tracing technology in dense urban scenes is used to determine whether a ray beam emitted in a dense urban scene intersects with an obstacle in the scene, and then calculate channel information in the dense urban scene, including the following steps:

[0008] Step 1: construct a solid polygon in a dense urban scene, and use the center of the solid polygon as the emission point to emit a ray beam to each face of the solid polygon. The face corresponding to each ray beam is the bottom polygon of the ray beam, and the vertex of the face corresponding to each ray beam is the vertex of the bottom polygon of the ray beam.

[0009] Step 2, select one of the ray beams and construct the support function of the corresponding ray beam bottom polygon;

[0010] Step 3: consider obstacles in the dense urban scene as polygons in the scene, construct support directions for the polygons in the scene, and construct support angles for the bottom polygons of the ray beam according to the support directions;

[0011] Step 4, calculate the support points of the polygons in the scene according to the support direction, calculate the support points of the bottom polygons of the ray beam according to the support angle, and calculate the vertices using the above two support points;

[0012] Step 5, constructing an intersection determination triangle according to the vertices calculated in step 4, and using the positional relationship between the intersection determination triangle and the origin to determine whether the polygon in the scene intersects with the bottom polygon of the ray beam; the origin is the origin of the plane rectangular coordinate system, that is, the center point of the solid polygon, and the X and Y axes of the plane rectangular coordinate system are perpendicular to the propagation direction of the ray beam;

[0013] Step 6: For the scene polygons that intersect with the bottom polygon of the ray beam, a new ray beam is generated using the principle of mirror reflection, and steps 2 to 5 are repeated until there are no scene polygons that intersect with the bottom polygon of the ray beam or all ray beams reach the preset upper limit of the number of reflections. The channel information in the dense urban scene is calculated by covering the information of the ray beams at the receiving points.

[0014] As a preferred solution of the present invention, the specific process of step 2 is as follows:

[0015] Step 2.1, calculate the normal vectors of each edge of the bottom polygon of the ray beam pointing outside the polygon, and convert the normal vectors into the polar coordinate system, and record the angle values ​​of each normal vector converted into the polar coordinate system;

[0016] Step 2.2, in the order of increasing angle values, record the angle values ​​and the edges of the corresponding ray beam bottom polygons in a list, and the list is the support function of the ray beam bottom polygon.

[0017] As a preferred solution of the present invention, the specific process of step 3 is as follows:

[0018] Step 3.1, if the current support direction is constructed for the first time, the support direction is assigned a vector [1,0];

[0019] Step 3.2, if the support direction has been constructed once, the support direction is assigned as a unit vector pointing from the vertex to the origin; the vertex is the vertex generated by the constructed support direction based on step 4;

[0020] Step 3.3, if the support direction has been constructed at least twice, the support direction is assigned as:

[0021]

[0022] in, is the assigned vector of the support direction, s1 and s2 are the vertices generated in step 4 based on the constructed support direction, o is the origin, and × is the cross product of the vector. is the vector from s1 to s2, s1 is the unit vector pointing to the origin;

[0023] Step 3.4, according to the support direction constructed in step 3.1, 3.2 or 3.3, convert the opposite direction of the support direction into the polar coordinate system, and record the angle value converted into the polar coordinate system, which is the support angle.

[0024] As a preferred solution of the present invention, the specific process of step 4 is as follows:

[0025] Step 4.1, calculating the support points of the polygons in the scene according to the support direction;

[0026] Step 4.1.1: Construct a vector with the origin pointing to each vertex of the polygon in the scene is the vector from the origin to the kth vertex of the polygon in the scene;

[0027] Step 4.1.2, transform each vector Multiply the distance d by the support direction constructed in step 3.1, 3.2 or 3.3 k ;

[0028] Step 4.1.3, the vertex of the polygon in the scene corresponding to the maximum distance value is the support point s of the polygon in the scene sce ;

[0029] Step 4.2, calculating the support points of the bottom polygon of the ray beam according to the support angle;

[0030] Step 4.2.1, query the support function of the bottom polygon of the ray beam to determine the angle value interval [a i ,a i+1 ), a i ,a i+1 is the two adjacent increasing angle values ​​in the support function list;

[0031] Step 4.2.2, according to the angle value interval [a i ,a i+1 ), find the angle value a i ,a i+1 The intersection of the two corresponding edges in the ray beam bottom polygon is the support point s of the ray beam bottom polygon. ra ;

[0032] Step 4.3, use the support points s of the polygons in the scene sce and the support points s of the ray beam bottom polygon ra The vertex s is calculated as follows: is the vector from the origin to s, For sce Point to ra Vector.

[0033] As a preferred solution of the present invention, the specific process of step 5 is as follows:

[0034] Step 5.1, if the current support direction is constructed for the first time, the vertex s obtained in step 4 is used as the first vertex s1 of the intersection determination triangle, and return to step 3;

[0035] Step 5.2, if the support direction has been constructed once, use the vertex s obtained in step 4 as the second vertex s2 of the intersection determination triangle, and determine whether the bottom polygon of the ray beam intersects with the polygon in the scene based on the positional relationship between s1, s2 and the origin; the details are as follows:

[0036] Step 5.2.1, calculate the vector product of the vertices s1 and s2 of the two constructed intersection judgment triangles and the origin o

[0037] Step 5.2.2, if Then the bottom polygon of the ray beam does not intersect with the polygon in the scene; return to step 2, select the remaining unselected ray beams, and continue steps 2 to 6;

[0038] Step 5.2.3, if Then return to step 3;

[0039] Step 5.3, if the support direction has been constructed twice, the vertex s obtained in step 4 is used as the third vertex s3 of the intersection determination triangle, and the positional relationship between s1, s2 and s3 and the origin is used to determine whether the bottom polygon of the ray beam intersects with the polygon in the scene; the details are as follows:

[0040] Step 5.3.1, if the intersection judgment triangle formed by s1, s2 and s3 contains the origin, the bottom polygon of the ray beam intersects with the polygon in the scene; if it does not contain the origin, go to step 5.3.2;

[0041] Step 5.3.2, if satisfied Then replace s2 with s3 as the new s2 and return to step 3; if Then replace s1 with s3 as the new s1 and return to step 3.

[0042] As a preferred solution of the present invention, the specific process of step 6 is as follows:

[0043] Step 6.1, for the polygon in the scene that intersects with the bottom polygon of the ray beam, generate a new ray beam using the principle of mirror reflection, and make the new ray beam continue to propagate in the scene;

[0044] Step 6.2, preset the number of mirror reflections, when no new ray beams are generated, determine whether all ray beams cover the receiving point, and calculate the channel information of the receiving point based on the ray beam information covering the receiving point.

[0045] A computer device comprises a memory, a processor, and a computer program stored in the memory and capable of running on the processor. When the processor executes the computer program, the steps of the intersection determination method applicable to the ray tracing technology for dense urban scenes are implemented.

[0046] A computer-readable storage medium stores a computer program, which, when executed by a processor, implements the steps of the intersection determination method applicable to ray tracing technology for dense urban scenes.

[0047] Compared with the prior art, the present invention adopts the above technical solution and has the following technical effects:

[0048] 1. The present invention constructs the support points of the polygons through the support direction and the support angle, thereby constructing an intersection determination triangle for the intersection determination of the original two polygons. By successively constructing the vertices of the intersection determination triangle and determining the positional relationship between the vertices and the origin, the steps of polygon intersection determination are greatly simplified and the accuracy of the intersection determination result is ensured.

[0049] 2. Compared with the existing polygon intersection determination method, the present invention can obtain accurate intersection determination results with higher computational efficiency, can obtain accurate channel information in a shorter simulation time, and has extremely high simulation efficiency in scenarios with a large number of receiving points. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Figure 1 It is a flow chart of an intersection determination method applicable to ray tracing technology for dense urban scenes of the present invention;

[0051] Figure 2 It is a schematic diagram of the intersection determination method of the present invention;

[0052] Figure 3 A schematic diagram of applying the method of the present invention to channel modeling measurement;

[0053] Figure 4 It is a schematic diagram of simulation results of applying the method of the present invention to channel modeling. DETAILED DESCRIPTION

[0054] The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be interpreted as limiting the present invention.

[0055] There are a large number of obstacles in dense urban scenes. In such scenes, the ray tracing algorithm has low computational efficiency. Therefore, the present invention proposes an intersection determination method suitable for dense urban scenes. The support function is used to simplify the polygon intersection problem. The vertices are calculated by the support function to quickly determine whether the polygons intersect, meeting the needs of ray tracing technology for efficient and accurate polygon intersection determination methods. Figure 1 As shown, the specific steps are as follows:

[0056] Step S1, emitting a plurality of ray beams with the emission point as the source point; specifically comprising:

[0057] S1.1. Construct a cube with a side length of 1 meter. The launch point is located at the center of the cube. With the six faces of the cube as the base and the center of the cube as the vertex, construct six quadrangular pyramids. They can be cubes, cuboids, or other three-dimensional polygons.

[0058] S1.2. The six generated quadrangular pyramid vertices are used as the source points of the projection ray beam, and the bottom surface of the quadrangular pyramid is used as the bottom surface of the projection ray beam, so as to generate six projection ray beams.

[0059] Step S2: Select an emitted ray beam and construct the support function of its bottom polygon; specifically including:

[0060] S2.1. Calculate the normal vectors of the edges of the bottom polygon of the ray beam pointing outside the polygon, convert these normal vectors into the polar coordinate system, and record their angle values ​​in the polar coordinate system [0,360°) in ascending order;

[0061] S2.2. Record these angle values ​​and the corresponding edges in a list. This list is the support function of the bottom polygon of the ray beam.

[0062] Step S3, constructing a support direction for the polygons in the scene, and constructing a support angle for the bottom polygons of the ray beam; specifically comprising:

[0063] S3.1. If the support direction has not been constructed before, assign the support direction to the vector [1,0];

[0064] S3.2. If a support direction has been constructed once before and the corresponding vertex has been generated, the support direction is assigned as a unit vector whose direction is the vertex pointing to the origin; the origin is the origin of the plane rectangular coordinate system, that is, the center point of the cube, and the X and Y axes of the plane rectangular coordinate system are perpendicular to the propagation direction of the ray beam;

[0065] S3.3. If more than one support direction has been constructed and the corresponding vertices have been generated, the support direction is assigned as:

[0066]

[0067] in, is the support direction, s1, s2 are the vertices generated in the first two times, o is the origin, and × is the cross product of the vector;

[0068] S3.4. Convert the opposite direction of the support direction into the polar coordinate system and record the angle value corresponding to [0,360°) on the polar coordinate system. This angle value is the support angle a.

[0069] Step S4, calculating the support points of the polygons in the scene according to the support direction, calculating the support points of the bottom polygons of the ray beam using the support angle, and performing vector operations using the two support points to obtain new vertices; specifically including:

[0070] S4.1. Calculate the support points of the polygons in the scene according to the support direction; the details are as follows:

[0071] S4.1.1. Construct a vector with its origin pointing to each vertex of the polygon in the scene is the vector from the origin to the kth vertex of the polygon in the scene;

[0072] S4.1.2. Vector With support direction Point product to get the distance value d k ;

[0073] S4.1.3. The vertex with the maximum distance value is the support point s of the scene polygon. sce .

[0074] S4.2. Calculate the support points of the bottom polygon of the ray beam according to the support angle; the details are as follows:

[0075] S4.2.1. Search within the support function of the ray beam bottom polygon and calculate the interval [a i ,a i+1 ), where a i is the angle value of the normal vector of the edge formed by the i-th and i+1-th vertices of the support function;

[0076] S4.2.2. According to the i-th interval corresponding to the support angle in the support function angle list, the i+1-th vertex of the ray polygon is the support point s ra .

[0077] S4.3, according to the support points s of the polygons in the scene sce and the support points s of the ray beam bottom polygon ra Calculate the new vertex s as follows:

[0078] Step S5, constructing an intersection determination triangle according to the new vertex, and determining whether the polygon in the scene intersects with the bottom polygon of the ray beam by using the positional relationship between the intersection determination triangle and the origin; specifically comprising:

[0079] S5.1. If the new vertex s is constructed for the first time, record the vertex s as the first vertex s1 of the intersection determination triangle, and return to step S3;

[0080] S5.2. If the vertex of the intersection determination triangle is constructed for the second time, this vertex s is recorded as the second vertex s2 of the intersection determination triangle, and whether the bottom polygon of the ray beam intersects with the polygon in the scene is determined based on the positional relationship between the two recorded vertices and the origin; the details are as follows:

[0081] S5.2.1. Calculate the vector product of the vertices s1 and s2 of the two constructed intersection determination triangles and the origin o

[0082]

[0083] S5.2.2 If Then the bottom polygon of the ray beam does not intersect with the polygons in the scene;

[0084] S5.2.3 If Then return to step S3.

[0085] S5.3. If the vertices of the intersection determination triangle have been constructed at least three times, record this vertex s as the third vertex s3 of the intersection determination triangle, and determine whether the bottom polygon of the ray beam intersects with the polygon in the scene based on the positional relationship between the three vertices s1, s2, s3 and the origin; the details are as follows:

[0086] S5.3.1. The three vertices of the intersection determination triangle are s1, s2, and s3. If the intersection determination triangle contains the origin, then the ray beam bottom polygon intersects with the scene polygon.

[0087] S5.3.2. If the intersection triangle does not contain the origin, then the vertex s1 or s2 needs to be replaced with vertex s3. Then replace vertex s2 with vertex s3; if Then replace vertex s1 with vertex s3;

[0088] S5.3.3. Return to step S3 based on the replaced vertices s1 and s2.

[0089] Step S6: Generate a new ray beam using the mirror reflection principle for the polygon in the scene that intersects with the bottom polygon of the ray beam. The channel information in this scene can be calculated by covering the information of the ray beam at the receiving point; specifically, it includes:

[0090] S6.1. For a polygon in the scene that intersects with the bottom polygon of the ray beam, generate a new ray beam using the principle of mirror reflection, and make the new ray beam continue to propagate in the scene;

[0091] S6.2. Calculate whether all the ray beams cover the receiving point, and calculate the channel characteristics of the receiving point based on information such as the propagation distance of the ray beams covering the receiving point.

[0092] Example

[0093] S1. Emit ray beams, where a ray beam needs to determine the intersection with the polygons in the scene. Figure 2 The trapezoid shown is the ray beam base polygon, and the triangle is the scene in-polygon.

[0094] S2. Calculate the normal vectors of the bottom polygon of the ray beam pointing outside the polygon, convert these normal vectors into the polar coordinate system, and record their increasing angle values ​​in the polar coordinate system [0,360°). The angle values ​​obtained here are: 26.57°, 90°, 153.43°, 270°, which correspond to the right side, top side, left side, and bottom side of the trapezoid, respectively.

[0095] S3. Structural support direction The support angle calculated according to the opposite direction is equal to 0°;

[0096] S4. Calculate the support point of the scene polygon according to the support direction. In this support direction, the leftmost vertex of the polygon (triangle) in the scene will obtain the largest distance value, so its leftmost vertex is recorded as the polygon support point s of the scene. sce . Calculate the support point of the ray polygon according to the support angle. According to the support angle of 0°, it is judged to be in the interval [270°, 26.57° + 360°). Therefore, the rightmost vertex of the bottom polygon (trapezoid) of the ray beam is the support point s ra .according to Calculate the first vertex s1 of the intersection determination triangle.

[0097] S5, at this time, only the vertex s1 of the intersection determination triangle is completed for the first time, so the support direction Modify the direction of the first vertex to point to the origin and calculate the support angle at the same time, construct the second vertex s2 of the intersection judgment triangle, such as Figure 2 shown.

[0098] At this point, the vertices of the intersection determination triangle have been constructed twice, and the calculation The calculated result is less than 0. Therefore, it is still impossible to determine whether the polygons intersect, and the third vertex needs to be constructed. Calculate the new support direction and support angle, and construct the third vertex s3 of the intersection judgment triangle.

[0099] At this point, the vertices of the intersection determination triangle have been constructed three times. According to the calculation, we get:

[0100]

[0101]

[0102] Therefore, the constructed intersection determination triangle contains the origin, and the ray beam bottom polygon intersects with the polygon in the scene.

[0103] S6. Send a new beam of rays, and calculate the channel characteristics of the receiving point based on the beam of rays covering the receiving point.

[0104] Figure 3 The present invention is applied to channel modeling. Figure 3 Simulation is performed in the constructed scenario to obtain channel characteristics such as received power. Figure 4 A schematic diagram of the simulation results of applying the present invention to channel modeling is shown. Compared with the traditional intersection determination method, the channel modeling method using the intersection determination of the present invention obtains more accurate channel information.

[0105] Table 1 shows the improvement of the present invention in terms of computational efficiency. When applied to the channel modeling simulation method, the present invention can improve the simulation speed by at least 100 times under different reflection order settings.

[0106] Table 1

[0107] Reflection Order 1 2 3 4 5 Traditional method simulation time (seconds) 6685 9894 11120 12032 13009 Simulation time of the method of the present invention (seconds) 2.68 7.45 17.05 32.84 58.03 The simulation time reduction of the present invention (%) 99.96 99.92 99.85 99.73 99.55

[0108] Based on the same inventive concept, an embodiment of the present application provides a computer device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the steps of the aforementioned intersection determination method applicable to ray tracing technology for dense urban scenes are implemented.

[0109] Based on the same inventive concept, an embodiment of the present application provides a computer-readable storage medium, which stores a computer program. When the computer program is executed by a processor, the steps of the aforementioned intersection determination method applicable to ray tracing technology for dense urban scenes are implemented.

[0110] Those skilled in the art will appreciate that embodiments of the present invention may be provided as methods, systems, or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0111] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0112] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0113] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0114] The above embodiments are only for illustrating the technical idea of ​​the present invention, and cannot be used to limit the protection scope of the present invention. Any changes made on the basis of the technical solution in accordance with the technical idea proposed by the present invention shall fall within the protection scope of the present invention.

Claims

1. An intersection determination method applicable to ray tracing technology in dense urban scenes, used to determine whether the ray beam emitted in a dense urban scene intersects with obstacles in the scene, and then calculate the channel information in the dense urban scene, characterized in that: The steps include: Step 1: construct a solid polygon in a dense urban scene, and use the center of the solid polygon as the emission point to emit a ray beam to each face of the solid polygon. The face corresponding to each ray beam is the bottom polygon of the ray beam, and the vertex of the face corresponding to each ray beam is the vertex of the bottom polygon of the ray beam. Step 2, select one of the ray beams and construct the support function of the corresponding ray beam bottom polygon; Step 3: consider obstacles in the dense urban scene as polygons in the scene, construct support directions for the polygons in the scene, and construct support angles for the bottom polygons of the ray beam according to the support directions; Step 4, calculate the support points of the polygons in the scene according to the support direction, calculate the support points of the bottom polygons of the ray beam according to the support angle, and calculate the vertices using the above two support points; Step 5, constructing an intersection determination triangle according to the vertices calculated in step 4, and using the positional relationship between the intersection determination triangle and the origin to determine whether the polygon in the scene intersects with the bottom polygon of the ray beam; the origin is the origin of the plane rectangular coordinate system, that is, the center point of the solid polygon, and the X and Y axes of the plane rectangular coordinate system are perpendicular to the propagation direction of the ray beam; Step 6: For the scene polygons that intersect with the bottom polygon of the ray beam, a new ray beam is generated using the principle of mirror reflection, and steps 2 to 5 are repeated until there are no scene polygons that intersect with the bottom polygon of the ray beam or all ray beams reach the preset upper limit of the number of reflections. The channel information in the dense urban scene is calculated by covering the information of the ray beams at the receiving points.

2. The intersection determination method for ray tracing technology applicable to dense urban scenes according to claim 1, characterized in that: The specific process of step 2 is as follows: Step 2.1, calculate the normal vectors of each edge of the bottom polygon of the ray beam pointing outside the polygon, and convert the normal vectors into the polar coordinate system, and record the angle values ​​of each normal vector converted into the polar coordinate system; Step 2.2, in the order of increasing angle values, record the angle values ​​and the edges of the corresponding ray beam bottom polygons in a list, and the list is the support function of the ray beam bottom polygon.

3. The intersection determination method applicable to dense urban scene ray tracing technology according to claim 2 is characterized in that: The specific process of step 3 is as follows: Step 3.1, if the current support direction is constructed for the first time, the support direction is assigned a vector [1,0]; Step 3.2, if the support direction has been constructed once, the support direction is assigned as a unit vector pointing from the vertex to the origin; the vertex is the vertex generated by the constructed support direction based on step 4; Step 3.3, if the support direction has been constructed at least twice, the support direction is assigned as: in, is the assigned vector of the support direction, s1 and s2 are the vertices generated in step 4 based on the constructed support direction, o is the origin, and × is the cross product of the vector. is the vector from s1 to s2, s1 is the unit vector pointing to the origin; Step 3.4, according to the support direction constructed in step 3.1, 3.2 or 3.3, convert the opposite direction of the support direction into the polar coordinate system, and record the angle value converted into the polar coordinate system, which is the support angle.

4. The intersection determination method applicable to dense urban scene ray tracing technology according to claim 3 is characterized in that: The specific process of step 4 is as follows: Step 4.1, calculating the support points of the polygons in the scene according to the support direction; Step 4.1.1: Construct a vector with the origin pointing to each vertex of the polygon in the scene is the vector from the origin to the kth vertex of the polygon in the scene; Step 4.1.2, transform each vector Multiply the distance d by the support direction constructed in step 3.1, 3.2 or 3.3 k ; Step 4.1.3, the vertex of the polygon in the scene corresponding to the maximum distance value is the support point s of the polygon in the scene sce ; Step 4.2, calculating the support points of the bottom polygon of the ray beam according to the support angle; Step 4.2.1, query the support function of the bottom polygon of the ray beam to determine the angle value interval [a i ,a i+1 ), a i ,a i+1 is the two adjacent increasing angle values ​​in the support function list; Step 4.2.2, according to the angle value interval [a i ,a i+1 ), find the angle value a i ,a i+1 The intersection of the two corresponding edges in the ray beam bottom polygon is the support point s of the ray beam bottom polygon. ra ; Step 4.3, using the support points s of the polygons in the scene sce and the support points s of the ray beam bottom polygon ra The vertex s is calculated as follows: is the vector from the origin to s, For sce Point to ra Vector.

5. The intersection determination method applicable to dense urban scene ray tracing technology according to claim 4 is characterized in that: The specific process of step 5 is as follows: Step 5.1, if the current support direction is constructed for the first time, the vertex s obtained in step 4 is used as the first vertex s1 of the intersection determination triangle, and return to step 3; Step 5.2, if the support direction has been constructed once, use the vertex s obtained in step 4 as the second vertex s2 of the intersection determination triangle, and determine whether the bottom polygon of the ray beam intersects with the polygon in the scene based on the positional relationship between s1, s2 and the origin; the details are as follows: Step 5.2.1, calculate the vector product of the vertices s1 and s2 of the two constructed intersection judgment triangles and the origin o Step 5.2.2, if Then the bottom polygon of the ray beam does not intersect with the polygons in the scene; Return to step 2, select the remaining unselected ray beams, and continue with steps 2 to 6; Step 5.2.3, if Then return to step 3; Step 5.3, if the support direction has been constructed twice, the vertex s obtained in step 4 is used as the third vertex s3 of the intersection determination triangle, and the positional relationship between s1, s2 and s3 and the origin is used to determine whether the bottom polygon of the ray beam intersects with the polygon in the scene; the details are as follows: Step 5.3.1, if the intersection judgment triangle formed by s1, s2 and s3 contains the origin, the bottom polygon of the ray beam intersects with the polygon in the scene; if it does not contain the origin, go to step 5.3.2; Step 5.3.2, if satisfied Then replace s2 with s3 as the new s2 and return to step 3; if Then replace s1 with s3 as the new s1 and return to step 3.

6. The intersection determination method applicable to dense urban scene ray tracing technology according to claim 5, characterized in that: The specific process of step 6 is as follows: Step 6.1, for the polygon in the scene that intersects with the bottom polygon of the ray beam, generate a new ray beam using the principle of mirror reflection, and make the new ray beam continue to propagate in the scene; Step 6.2, preset the number of mirror reflections, when no new ray beams are generated, determine whether all ray beams cover the receiving point, and calculate the channel information of the receiving point based on the ray beam information covering the receiving point.

7. A computer device comprising a memory, a processor, and a computer program stored in the memory and capable of running on the processor, characterized in that: When the processor executes the computer program, the steps of the intersection determination method applicable to the ray tracing technology for dense urban scenes as described in any one of claims 1 to 6 are implemented.

8. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the steps of the intersection determination method applicable to the ray tracing technology for dense urban scenes as described in any one of claims 1 to 6 are implemented.

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