Dynamic three-dimensional simulation image real-time rendering method and system based on electronic chart

Abstract

The invention relates to the technical field of image processing, in particular to a dynamic three-dimensional simulation image real-time rendering method and system based on an electronic chart, and the method comprises the steps: obtaining two-dimensional electronic chart data and dynamic real-time data; generating a three-dimensional simulation image based on the obtained two-dimensional electronic chart data, and rendering the obtained three-dimensional simulation image in real time; dynamically adjusting the rendering priority of the key three-dimensional simulation image during rendering; after the dynamic real-time data are received, updating the three-dimensional simulation image and dynamically rendering the three-dimensional simulation image; the two-dimensional electronic chart data comprises geographic coordinates, water depth data, channel data, shoreline data, obstacle data and object attribute data; the object attribute data comprises object types, object height data and object level data; the dynamic real-time data comprises update data of the two-dimensional electronic chart and maritime affair notification information.

Description

Technical Field

[0001] The present invention relates to the field of image processing technology, and in particular to a method and system for real-time rendering of dynamic three-dimensional simulation images based on electronic nautical charts. Background Art

[0002] Electronic Navigational Chart (ENC) is a digital nautical chart used for modern ship navigation. It replaces traditional paper charts and integrates real-time data through electronic devices (such as the Electronic Chart Display and Information System ECDIS), significantly improving navigation safety and efficiency.

[0003] Through data fusion (supplementing elevation and model) and coordinate conversion, electronic charts in three-dimensional scenes can be generated based on two-dimensional electronic charts. For example, the open source three-dimensional earth engine CesiumJS supports loading electronic chart data (such as GeoJSON format) and generates three-dimensional ocean scenes in combination with terrain services. ESRIArcGIS Pro: Achieve three-dimensional visualization of the seabed by fusing BathymetricAttributedGrid (BAG) data with ENC. Professional navigation simulators Polaris and Navi-Trainer integrate three-dimensional vision with electronic chart data.

[0004] When rendering three-dimensional simulation images in a three-dimensional scene, the technical ideas of the existing technology are mainly focused on: separating the style from the spatial data, improving efficiency by pre-querying the display style library, and decoupling attribute parsing and graphics rendering; or reducing the complexity of real-time calculations through layered processing of coordinate transformation, that is, phased conversion (geography → plane → screen); and using instruction merging and dynamic clipping to significantly reduce the number of drawing commands.

[0005] However, no consideration has been given to how to optimize the rendering process of electronic charts in three-dimensional scenarios when two-dimensional electronic chart versions are updated or maritime notifications are received; nor to the dynamic rendering of objects during automatic navigation. Summary of the invention

[0006] The present invention dynamically adjusts the rendering priority of key three-dimensional simulation images through dynamic object criticality scoring, thereby ensuring smooth three-dimensional image rendering.

[0007] The technical solution proposed by the present invention is: a real-time rendering method of a dynamic three-dimensional simulation image based on an electronic nautical chart, the method comprising: Obtain 2D electronic chart data and dynamic real-time data; Generate 3D simulation images based on the acquired 2D electronic chart data, and render the acquired 3D simulation images in real time; dynamically adjust the rendering priority of key 3D simulation images during rendering; After receiving dynamic real-time data, the three-dimensional simulation image is updated and dynamically rendered; The two-dimensional electronic chart data includes geographic coordinates, water depth data, channel data, shoreline data, obstacle data, and object attribute data; The object attribute data includes object type, object height data, and object level data; The dynamic real-time data includes update data of two-dimensional electronic nautical charts and maritime notification information.

[0008] Preferably, generating a three-dimensional simulation image based on the acquired two-dimensional electronic chart data includes: Convert the water depth data in the two-dimensional electronic chart data into gridded elevation points, and generate a continuous three-dimensional seabed surface by combining the interpolation algorithm; Generate three-dimensional coastline terrain by combining the shoreline data in the two-dimensional electronic chart data with the digital elevation model (DEM) of surface buildings and facilities; Generate a three-dimensional display model of the object according to the object attribute data; Convert geographic coordinates longitude and latitude into a local coordinate system supported by the 3D engine, and correct projection distortion using the UTM partitioning algorithm; Project the ship's dynamic position, i.e. AIS data, into the local coordinate system; The real-time rendering of the obtained three-dimensional simulation image comprises: Load ocean material data, ship texture data, vertex shader and fragment shader; Layered by object type, including terrain layer, dynamic object layer and UI layer; Detect whether the bounding box of the object's 3D display model intersects with the viewing cone; Select the LOD level based on the distance from the object to the camera; Submit transformation matrices for similar objects in batches, perform lighting calculations using the Phong lighting model, generate depth maps, and use them for real-time shadow calculations.

[0009] Preferably, after receiving the dynamic real-time data, updating the three-dimensional simulation image and dynamically rendering it includes: Obtain updated data, including incremental files in IHO S-57 / S-101 format or JSON / XML messages of maritime notices; Extract the scope of the update area, the object type, the longitude and latitude coordinates, and the object attribute data from the update data; Use differential coding to extract the transformed part of the updated data relative to the original 2D chart data, avoiding full data analysis; Matching the display style of the object based on the object type, that is, querying the IHO ECDIS display library according to the object data to obtain the corresponding three-dimensional display model as the newly added object model; Convert the longitude and latitude of the newly added object model into local coordinates supported by the 3D engine; use the newly added object model to update the original object model; If the materials of the newly added object models are the same, the drawing instructions of the newly added object models will be merged into a single batch and submitted to reduce the number of GPU calls; For the same newly added object models, use the instanced rendering algorithm for batch processing.

[0010] Preferably, the real-time rendering of the obtained three-dimensional simulation image further includes: Highlight the key features of the 3D simulation image of key objects and avoid redundant calculations, including: Define semantic importance based on object attributes, that is, set object priority weights based on object data ; Based on the object moving speed , distance from the viewpoint and interaction frequency , to evaluate the criticality of the object, that is, the criticality score of the object ;in, They represent weight coefficients respectively, They represent the maximum speed, maximum viewing distance, and maximum interaction frequency, respectively; Acquire a three-dimensional simulated image of objects related to the current navigation task, wherein the objects related to the navigation task include obstacles in the channel, channel lines, and ships in the same channel; if , then the corresponding object is judged to be a key object; among them, represents the critical evaluation threshold; All conditions that meet The objects are arranged in descending order according to their criticality scores to form a priority sequence; and the first K objects are selected as key objects for dynamic rendering, and the K value is dynamically adjusted according to the GPU memory.

[0011] Preferably, the real-time rendering of the obtained three-dimensional simulation image further includes: In the rendering process of the selected K objects, the highest precision LOD is used and the view distance degradation is prohibited; that is: No. The accuracy of the object ; In the fragment shader, add edge detection and color overlay, and add a spotlight effect to the key objects to improve their visual contrast. ;in, Represent the light source direction vector and the surface normal of the key object respectively; Represents the light intensity coefficient; ; Represents the basic visual contrast; Use MSAA 4× anti-aliasing and HDR algorithms to render key objects independently; Use low sampling rate and simplified shaders for rendering non-critical objects; Parallel task allocation to GPU and CPU, that is, The screening of key objects and the processing of key object data use CPU thread 1; Non-critical object LOD calculation uses CPU thread 2; The rendering and lighting enhancement of key objects use GPU Compute Shader and allocate a fixed thread area to store the 3D display model of key objects; The textures of non-key objects are compressed using the BC7 compression algorithm, and the textures of key objects use the lossless RGBA32 format.

[0012] Preferably, the real-time rendering of the obtained three-dimensional simulation image further includes: Dynamically schedule computing resources based on priority, including: Based on the priority sequence, 70% of GPU time is reserved for rendering key objects in each frame; If the temporal rendering time is greater than the target frame time, the LOD level of non-critical objects will be lowered first; It is forbidden to detect whether the bounding box of the 3D model of the key object intersects with the view frustum, that is, it is forbidden to perform the view frustum culling operation on the key object; When detecting whether the bounding box of the 3D model of non-critical objects intersects with the view frustum, expand the view frustum culling range to ,in, Indicates the frustum culling range of non-critical objects.

[0013] Preferably, dynamically adjusting the rendering priority of the key three-dimensional simulation image during rendering includes: The three-dimensional display model of the key object is defined as a key three-dimensional simulation image; Get route information and divide the route into multiple waypoints, that is, the route can be represented as a collection of multiple waypoints; Set up routes , dividing the route into multiple segments ;in Indicates the number of waypoints, ; Calculate the navigation angle for each segment and length , set the path influence radius , only the correlation between the key objects and the path within the path influence radius is considered; Optimize the priority score calculation process and propose a dynamic priority calculation process, including: Set the vertical distance attenuation function ,in, represents the Gaussian attenuation coefficient, Indicates the shortest distance between the object and the flight segment; Setting the Directional Consistency Score ;in Indicates the angle between the object and the current course; Then, the criticality score of the dynamic object associated with the route is , Respectively represent the dynamic weight coefficient, Indicates a semantic priority, wherein the semantic priority is set based on the object type; Dynamic object selection and resource allocation based on the criticality scores of dynamic objects associated with the route, including: choose and The object is taken as the key object, among which, Respectively represent the distance-related threshold and the angle-related threshold; The criticality scores of the dynamic objects associated with the route are arranged in ascending order to form a dynamic object priority sequence. Full precision rendering of key objects; if , the corresponding object will be rendered regardless of whether it is within the path influence radius; Allocate independent GPU time for rendering of key objects.

[0014] Preferably, the dynamic object key scores associated with the route are arranged in ascending order to form a dynamic object priority sequence, and each frame only counts the top Key objects are rendered in full precision, including: When rendering, the criticality score of the dynamic objects associated with the route is used to determine the front Add luminous borders of different luminous intensities to each key object and keep the highest LOD level, that is, LOD0 level; A direction arrow is generated at each key landmark position, and the direction arrow points to the next waypoint.

[0015] The present invention also provides a real-time rendering system for dynamic three-dimensional simulated images based on electronic nautical charts, including a processor, and a memory and a communication module connected to the processor. The system is used to execute the real-time rendering method for dynamic three-dimensional simulated images based on electronic nautical charts.

[0016] The present invention also provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and the computer program is executed by a processor to implement the method for real-time rendering of dynamic three-dimensional simulation images based on electronic nautical charts.

[0017] Beneficial effects of the present invention: The present invention updates the electronic nautical chart in a three-dimensional scene in real time when a two-dimensional electronic nautical chart is updated or a maritime notification is received, and quickly responds to changes in the nautical chart through incremental data processing and dynamic rendering optimization, thereby achieving a smooth interactive experience.

[0018] 2. During dynamic rendering optimization, the present invention dynamically highlights route-related objects in the three-dimensional scene through path correlation analysis combined with priority (criticality score of dynamic objects associated with the route), and retains objects with the highest priority, so as to balance navigation guidance and global information display of the nautical chart, and adapt to scenes with high real-time requirements such as automatic navigation of ships. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 The present invention is a flow chart of a method for real-time rendering of dynamic three-dimensional simulation images based on electronic nautical charts. DETAILED DESCRIPTION

[0020] The following description is used to disclose the present invention so that those skilled in the art can implement the present invention. The preferred embodiments described below are only examples, and those skilled in the art can think of other obvious variations. The basic principles of the present invention defined in the following description can be applied to other embodiments, variations, improvements, equivalents, and other technical solutions that do not deviate from the spirit and scope of the present invention.

[0021] It is to be understood that the term "one" should be understood as "at least one" or "one or more", that is, in one embodiment, the number of an element may be one, while in another embodiment, the number of the element may be multiple, and the term "one" should not be understood as a limitation on the quantity.

[0022] Embodiment 1: refer to Figure 1 The technical solution provided by the present invention is: a real-time rendering method of a dynamic three-dimensional simulation image based on an electronic nautical chart, comprising the following steps: Step 1: Obtain two-dimensional electronic chart data and dynamic real-time data; Step 2: Generate a three-dimensional simulation image based on the acquired two-dimensional electronic chart data, and render the acquired three-dimensional simulation image in real time; dynamically adjust the rendering priority of the key three-dimensional simulation image during rendering.

[0023] Step 3: After receiving the dynamic real-time data, update the three-dimensional simulation image and dynamically render it.

[0024] The step 2 of generating a three-dimensional simulation image based on the acquired two-dimensional electronic chart data includes the following steps: Convert the water depth data in the two-dimensional electronic chart data into gridded elevation points, and generate a continuous three-dimensional seabed surface by combining the interpolation algorithm; Generate three-dimensional coastline terrain by combining the shoreline data in the two-dimensional electronic chart data with the digital elevation model (DEM) of surface buildings and facilities; Generate a three-dimensional display model of the object according to the object attribute data; Convert geographic coordinates longitude and latitude into a local coordinate system supported by the 3D engine, and correct projection distortion using the UTM partitioning algorithm; The dynamic position of the ship, i.e. AIS data, is projected into the local coordinate system.

[0025] The real-time rendering of the obtained three-dimensional simulation image in step 2 includes the following steps: Load ocean material data, ship texture data, vertex shader and fragment shader; Layered by object type, including terrain layer, dynamic object layer and UI layer; read object type (including lighthouses, buoys, obstacles, ships, etc.) from standard electronic chart files (ENC) Check whether the bounding box of the 3D display model of the object intersects with the view frustum; that is, perform the view frustum culling operation. Select the LOD level according to the distance from the object to the camera; for example, when the object is less than 1000 meters away from the camera, the LOD level is LOD0 and the number of triangles is 10,000; when the object is between 1000 and 1500 meters away from the camera, the LOD level is LOD1 and the number of triangles is 2000; when the object is more than 1500 meters away from the camera, the LOD level is LOD2 and the number of triangles is 500.

[0026] Submit transformation matrices for similar objects in batches, perform lighting calculations using the Phong lighting model, generate depth maps, and use them for real-time shadow calculations.

[0027] Wherein, in step 2, dynamically adjusting the rendering priority of the key three-dimensional simulation image during rendering includes the following steps: Filter out key objects, highlight the key features of the 3D simulation images of key objects, and avoid redundant calculations, including: Define semantic importance based on object attributes, that is, set object priority weights based on object data For example, if the object is an obstacle, the priority weight is 0.8, and if the object is a buoy, the priority weight is 0.6.

[0028] Based on the object moving speed , distance from the viewpoint and interaction frequency , to evaluate the criticality of the object, that is, the criticality score of the object ;in, They represent weight coefficients respectively, They represent the maximum speed, maximum viewing distance, and maximum interaction frequency, respectively; Acquire a three-dimensional simulated image of objects related to the current navigation task, wherein the objects related to the navigation task include obstacles in the channel, channel lines, and ships in the same channel; if , then the corresponding object is judged to be a key object; among them, represents the critical evaluation threshold; All conditions that meet The objects are arranged in descending order according to their criticality scores to form a priority sequence; and the first K objects are selected as key objects for dynamic rendering, and the K value is dynamically adjusted according to the GPU memory.

[0029] In the rendering process of the selected K objects, the highest precision LOD is used and the viewing distance degradation is prohibited to highlight the key features (contrast, texture, etc.) of the three-dimensional simulation image of the key objects; that is: No. The accuracy of the object ; In the fragment shader, add edge detection and color overlay, and add a spotlight effect to the key objects to improve their visual contrast. ;in, Represent the light source direction vector and the surface normal of the key object respectively; Represents the light intensity coefficient; ; Represents the basic visual contrast; Use MSAA 4× anti-aliasing and HDR algorithms to render key objects independently; Use low sampling rate and simplified shaders for rendering non-critical objects; Parallel task allocation to GPU and CPU, that is, The screening of key objects and the processing of key object data use CPU thread 1; Non-critical object LOD calculation uses CPU thread 2; The rendering and lighting enhancement of key objects use GPU Compute Shader and allocate a fixed thread area to store the 3D display model of key objects; The textures of non-key objects are compressed using the BC7 compression algorithm, and the textures of key objects use the lossless RGBA32 format.

[0030] Among them, step 3 can be implemented by the following steps: Step 3.1, obtain update data, including incremental files in IHO S-57 / S-101 format or JSON / XML messages of maritime notices; Step 3.2, extracting the scope of the update area, object type, longitude and latitude coordinates, and object attribute data from the update data; Step 3.3: Use differential coding to extract the transformed part of the updated data relative to the original two-dimensional chart data to avoid full data analysis; Step 3.4, matching the object display style based on the object type, that is, querying the IHO ECDIS display library according to the object data, and obtaining the corresponding three-dimensional display model as the newly added object model; Step 3.5, convert the longitude and latitude of the newly added object model into local coordinates supported by the 3D engine; use the newly added object model to update the original object model; Step 3.6: If the materials of the newly added object models are the same, merge the drawing instructions of the newly added object models into a single batch and submit them to reduce the number of GPU calls; For the same newly added object models, use the instanced rendering algorithm for batch processing.

[0031] Embodiment 2: In scenarios with high real-time requirements such as ship automatic navigation and drone route monitoring, in order to balance navigation guidance and global information display, only key objects associated with the route path are rendered. That is, through path proximity analysis, route-related objects are dynamically highlighted in the three-dimensional scene, while retaining high-priority targets.

[0032] Based on the first embodiment, the following technical solution is proposed: Dynamically adjust the rendering priority of key 3D simulation images during rendering, including: The three-dimensional display model of the key object is defined as a key three-dimensional simulation image; Get route information and divide the route into multiple waypoints, that is, the route can be represented as a collection of multiple waypoints; Set up routes , dividing the route into multiple segments ;in Indicates the number of waypoints, ; Calculate the navigation angle for each segment and length , set the path influence radius , only the correlation between the key objects and the path within the path influence radius is considered; Optimize the priority score calculation process and propose a dynamic priority calculation process, including: Set the vertical distance attenuation function ,in, represents the Gaussian attenuation coefficient, Indicates the shortest distance between the object and the flight segment; Setting the Directional Consistency Score ;in Indicates the angle between the object and the current course; Then, the criticality score of the dynamic object associated with the route is , Respectively represent the dynamic weight coefficient, Indicates a semantic priority, wherein the semantic priority is set based on the object type; Dynamic object selection and resource allocation based on the criticality scores of dynamic objects associated with the route, including: choose and The object is taken as the key object, among which, Respectively represent the distance-related threshold and the angle-related threshold; The criticality scores of the dynamic objects associated with the route are arranged in ascending order to form a dynamic object priority sequence. Key objects are rendered with full precision; specifically: To perform layered rendering: The first layer: Rendering path-related objects, that is, according to the criticality score of dynamic objects associated with the route, Each key object is added with a luminous frame of different luminous intensity (the brightness of the luminous frame changes with the dynamic object's criticality score). In addition, a direction arrow is generated at each key object position, and the direction arrow points to the next waypoint. Second layer: Render high priority objects, lock LOD and apply depth offset, that is, keep the highest LOD level of key objects, that is, LOD0 level.

[0033] The third layer: simplify the rendering of other objects, that is, non-critical objects are rendered with low LOD and no special effects (luminous borders, arrows). In this embodiment, performance monitoring can also be performed as needed: Statistics on the rendering time of each layer, dynamically adjust the maximum number of objects rendered per frame and To maintain frame rate; allocate independent GPU time for rendering of key objects.

[0034] And, if , the corresponding object will be rendered regardless of whether it is within the path influence radius.

[0035] The present invention also provides a real-time rendering system for dynamic three-dimensional simulated images based on electronic nautical charts, including a processor, and a memory and a communication module connected to the processor. The system is used to execute the real-time rendering method for dynamic three-dimensional simulated images based on electronic nautical charts.

[0036] The present invention also provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and the computer program is executed by a processor to implement the method for real-time rendering of dynamic three-dimensional simulation images based on electronic nautical charts.

[0037] In the embodiments disclosed in the present invention, the process described above with reference to the flowchart can be implemented as a computer software program. The embodiments disclosed in the present invention include a computer program product, which includes a computer program carried on a computer-readable medium, and the computer program contains program code for executing the method shown in the flowchart. In such an embodiment, the computer program can be downloaded and installed from the network through the communication part, and / or installed from a removable medium. When the computer program is executed by the central processing unit (CPU), the above functions defined in the method of the present invention are executed. It should be noted that the above-mentioned computer-readable medium of the present invention can be a computer-readable signal medium or a computer-readable storage medium or any combination of the above two. The computer-readable storage medium can be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared or semiconductor system, device or device, or any combination of the above. More specific examples of computer-readable storage media can include, but are not limited to: an electrical connection with one or more wire segments, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above. In the present invention, a computer-readable storage medium may be any tangible medium containing or storing a program that may be used by or in combination with an instruction execution system, device, or device. In the present invention, a computer-readable signal medium may include a data signal propagated in a baseband or as part of a carrier wave, which carries a computer-readable program code. Such propagated data signals may take a variety of forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination of the above. A computer-readable signal medium may also be any computer-readable medium other than a computer-readable storage medium, which may send, propagate, or transmit a program for use by or in combination with an instruction execution system, device, or device. The program code contained on the computer-readable medium may be transmitted using any suitable medium, including but not limited to: wireless segments, wire segments, optical cables, RF, etc., or any suitable combination of the above.

[0038] The flowcharts and block diagrams in the accompanying drawings illustrate the possible architecture, functions and operations of the systems, methods and computer program products according to various embodiments of the present invention. In this regard, each box in the flowchart or block diagram can represent a module, a program segment or a part of a code, and the module, a program segment or a part of the code contains one or more executable instructions for implementing the specified logical functions. It should also be noted that in some alternative implementations, the functions marked in the box can also occur in a different order from the order marked in the accompanying drawings. For example, two boxes represented in succession can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each box in the block diagram and / or flowchart, and the combination of boxes in the block diagram and / or flowchart can be implemented with a dedicated hardware-based system that performs the specified function or operation, or can be implemented with a combination of dedicated hardware and computer instructions.

[0039] Those skilled in the art should understand that the embodiments of the present invention described above and shown in the accompanying drawings are only examples and do not limit the present invention. The objectives of the present invention have been fully and effectively achieved. The functions and structural principles of the present invention have been demonstrated and explained in the embodiments. Without departing from the principles, the implementation methods of the present invention may be subject to any changes or modifications.

Claims

1. A real-time rendering method for dynamic three-dimensional simulation images based on electronic nautical charts, characterized in that: The method comprises: Obtain 2D electronic chart data and dynamic real-time data; Generate 3D simulation images based on the acquired 2D electronic chart data, and render the acquired 3D simulation images in real time; dynamically adjust the rendering priority of key 3D simulation images during rendering; After receiving dynamic real-time data, the three-dimensional simulation image is updated and dynamically rendered; The two-dimensional electronic chart data includes geographic coordinates, water depth data, channel data, shoreline data, obstacle data, and object attribute data; The object attribute data includes object type, object height data, and object level data; The dynamic real-time data includes update data of two-dimensional electronic nautical charts and maritime notification information.

2. The method for real-time rendering of dynamic three-dimensional simulation images based on electronic charts according to claim 1 is characterized in that: The method of generating a three-dimensional simulation image based on the acquired two-dimensional electronic chart data comprises: Convert the water depth data in the two-dimensional electronic chart data into gridded elevation points, and generate a continuous three-dimensional seabed surface by combining the interpolation algorithm; Generate three-dimensional coastline terrain by combining the shoreline data in the two-dimensional electronic chart data with the digital elevation model (DEM) of surface buildings and facilities; Generate a three-dimensional display model of the object according to the object attribute data; Convert geographic coordinates longitude and latitude into a local coordinate system supported by the 3D engine, and correct projection distortion using the UTM partitioning algorithm; Project the ship's dynamic position, i.e. AIS data, into the local coordinate system; The real-time rendering of the obtained three-dimensional simulation image comprises: Load ocean material data, ship texture data, vertex shader and fragment shader; Layered by object type, including terrain layer, dynamic object layer and UI layer; Detect whether the bounding box of the object's 3D display model intersects with the viewing cone; Select the LOD level based on the distance from the object to the camera; Submit transformation matrices for similar objects in batches, perform lighting calculations using the Phong lighting model, generate depth maps, and use them for real-time shadow calculations.

3. The method for real-time rendering of dynamic three-dimensional simulation images based on electronic nautical charts according to claim 2 is characterized in that: After receiving the dynamic real-time data, updating the three-dimensional simulation image and dynamically rendering it includes: Obtain updated data, including incremental files in IHO S-57 / S-101 format or JSON / XML messages of maritime notices; Extract the scope of the update area, the object type, the longitude and latitude coordinates, and the object attribute data from the update data; Use differential coding to extract the transformed part of the updated data relative to the original 2D chart data, avoiding full data analysis; Matching the display style of the object based on the object type, that is, querying the IHO ECDIS display library according to the object data to obtain the corresponding three-dimensional display model as the newly added object model; Convert the longitude and latitude of the newly added object model into local coordinates supported by the 3D engine; use the newly added object model to update the original object model; If the materials of the newly added object models are the same, the drawing instructions of the newly added object models will be merged into a single batch and submitted to reduce the number of GPU calls; For the same newly added object models, use the instanced rendering algorithm for batch processing.

4. The method for real-time rendering of dynamic three-dimensional simulation images based on electronic charts according to claim 3 is characterized in that: The real-time rendering of the obtained three-dimensional simulation image also includes: Highlight the key features of the 3D simulation image of key objects and avoid redundant calculations, including: Define semantic importance based on object attributes, that is, set object priority weights based on object data ; Based on the object moving speed , distance from the viewpoint and interaction frequency , to evaluate the criticality of the object, that is, the criticality score of the object ;in, They represent weight coefficients respectively, They represent the maximum speed, maximum viewing distance, and maximum interaction frequency, respectively; Acquire a three-dimensional simulated image of objects related to the current navigation task, wherein the objects related to the navigation task include obstacles in the channel, channel lines, and ships in the same channel; if , then the corresponding object is judged to be a key object; among them, represents the critical evaluation threshold; All conditions that meet The objects are arranged in descending order according to their criticality scores to form a priority sequence; and the first K objects are selected as key objects for dynamic rendering, and the K value is dynamically adjusted according to the GPU memory.

5. The method for real-time rendering of dynamic three-dimensional simulation images based on electronic charts according to claim 4 is characterized in that: The real-time rendering of the obtained three-dimensional simulation image also includes: In the rendering process of the selected K objects, the highest precision LOD is used and the view distance degradation is prohibited; that is: No. The accuracy of the object ; In the fragment shader, add edge detection and color overlay, and add a spotlight effect to the key objects to improve their visual contrast. ;in, Represent the light source direction vector and the surface normal of the key object respectively; Represents the light intensity coefficient; ; Represents the basic visual contrast; Use MSAA 4× anti-aliasing and HDR algorithms to render key objects independently; Use low sampling rate and simplified shaders for rendering non-critical objects; Parallel task allocation to GPU and CPU, that is, The screening of key objects and the processing of key object data use CPU thread 1; Non-critical object LOD calculation uses CPU thread 2; The rendering and lighting enhancement of key objects use GPU Compute Shader and allocate a fixed thread area to store the 3D display model of key objects; The textures of non-key objects are compressed using the BC7 compression algorithm, and the textures of key objects use the lossless RGBA32 format.

6. The method for real-time rendering of dynamic three-dimensional simulation images based on electronic nautical charts according to claim 5 is characterized in that: The real-time rendering of the obtained three-dimensional simulation image also includes: Dynamically schedule computing resources based on priority, including: Based on the priority sequence, 70% of GPU time is reserved for rendering key objects in each frame; If the temporal rendering time is greater than the target frame time, the LOD level of non-critical objects will be lowered first; It is forbidden to detect whether the bounding box of the 3D model of the key object intersects with the view frustum, that is, it is forbidden to perform the view frustum culling operation on the key object; When detecting whether the bounding box of the 3D model of non-critical objects intersects with the view frustum, expand the view frustum culling range to ,in, Indicates the frustum culling range of non-critical objects.

7. The method for real-time rendering of dynamic three-dimensional simulation images based on electronic charts according to claim 6 is characterized in that: The dynamically adjusting the rendering priority of the key three-dimensional simulation image during rendering includes: The three-dimensional display model of the key object is defined as a key three-dimensional simulation image; Get route information and divide the route into multiple waypoints, that is, the route can be represented as a collection of multiple waypoints; Set up routes , dividing the route into multiple segments ;in Indicates the number of waypoints, ; Calculate the navigation angle for each segment and length , set the path influence radius , only the correlation between the key objects and the path within the path influence radius is considered; Optimize the priority score calculation process and propose a dynamic priority calculation process, including: Set the vertical distance attenuation function ,in, represents the Gaussian attenuation coefficient, Indicates the shortest distance between the object and the flight segment; Setting the Directional Consistency Score ;in Indicates the angle between the object and the current course; Then, the criticality score of the dynamic object associated with the route is , Respectively represent the dynamic weight coefficient, Indicates a semantic priority, wherein the semantic priority is set based on the object type; Dynamic object selection and resource allocation based on the criticality scores of dynamic objects associated with the route, including: choose and The object is taken as the key object, among which, Respectively represent the distance-related threshold and the angle-related threshold; The criticality scores of the dynamic objects associated with the route are arranged in ascending order to form a dynamic object priority sequence. Key objects are rendered with full precision; if , the corresponding object will be rendered regardless of whether it is within the path influence radius; Allocate independent GPU time for rendering of key objects.

8. The method for real-time rendering of dynamic three-dimensional simulation images based on electronic nautical charts according to claim 7 is characterized in that: The dynamic object key scores associated with the route are arranged in ascending order to form a dynamic object priority sequence. Key objects are rendered in full precision, including: When rendering, the criticality score of the dynamic objects associated with the route is used to determine the front Add luminous borders of different luminous intensities to each key object and keep the highest LOD level, that is, LOD0 level; A direction arrow is generated at each key landmark position, and the direction arrow points to the next waypoint.

9. A dynamic three-dimensional simulation image real-time rendering system based on an electronic nautical chart, comprising a processor, a memory and a communication module connected to the processor, characterized in that: The system is used to execute the real-time rendering method of dynamic three-dimensional simulation images based on electronic nautical charts as described in any one of claims 1 to 8.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, and the computer program is executed by a processor to implement the method for real-time rendering of dynamic three-dimensional simulation images based on electronic nautical charts as described in any one of claims 1 to 8.

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