A method for eliminating jitter in a global three-dimensional map system

Abstract

The present invention relates to a method for eliminating jitter in a global three-dimensional map system, comprising the following steps: S1, using hardware equipment to project and establish a virtual spherical three-dimensional map in real space; S2, with the center of the virtual spherical three-dimensional map as the center, forming a plurality of origin coordinates according to the intersection of integer longitude and latitude lines on the spherical surface, and positioning and selecting a submap on the spherical surface of the virtual spherical three-dimensional map using four adjacent origin coordinates; S3, zooming and displaying the virtual spherical three-dimensional map with the center of the sphere as the initial origin, when the submap is rotated in a zoomed state with a resolution accuracy less than a threshold, performing a radian floating-point operation with the origin coordinate closest to the viewpoint to obtain a first rotation radian of the submap where the viewpoint is located; and S4, the rotation radians of the remaining submaps connected to the submap where the viewpoint is located are equal to the first rotation radian.

Description

Technical Field

[0001] The present invention relates to the technical field of geographic information systems, and in particular to a method for eliminating jitter in a global three-dimensional map system. Background Art

[0002] Geographic Information Systems (GIS) technology is a spatial information processing technology that has rapidly developed in recent years. Based on geographic space, it employs geographic model analysis methods to provide a variety of spatial and dynamic geographic information. It is a computer technology system that serves geographic research and decision-making. Its basic function is to convert tabular data from databases, spreadsheets, or directly entered into programs into geographic graphic displays, allowing for browsing, manipulation, and analysis of the displayed results. It not only effectively manages various resource and environmental information with spatial attributes, but also conducts rapid and repetitive analysis and testing of resource and environmental management practices, thereby enabling decision-making and scientific and policy standard evaluation. Due to the limitations of computer computing power and graphics card performance, 3D mapping systems can encounter jitter when rendering some high-precision maps. This jitter is caused by excessive rounding errors in floating-point operations. The current mainstream approach to addressing jitter is the dynamic coordinate method, which uses camera coordinates as the viewpoint origin coordinates. However, this method requires recalculating all vertices in the entire scene after each rotation, which significantly consumes GPU resources. Summary of the Invention

[0003] Based on this, it is necessary to provide a global three-dimensional map system jitter elimination method to address the situation where existing solutions for three-dimensional map jitter consume too much GPU resources.

[0004] A method for eliminating jitter in a global three-dimensional map system comprises the following steps:

[0005] S1, using hardware equipment to project and establish a virtual spherical three-dimensional map in real space;

[0006] S2, with the center of the virtual spherical three-dimensional map as the center, forming a plurality of origin coordinates according to the intersection of integer longitude and latitude lines on the sphere, and positioning a sub-map on the spherical surface of the virtual spherical three-dimensional map using four adjacent origin coordinates;

[0007] S3, the virtual spherical three-dimensional map is zoomed and displayed with the center of the sphere as the initial origin. When the sub-map is rotated in a zoomed state with a resolution accuracy less than a threshold, a radian floating-point operation is performed using the coordinates of the origin closest to the viewpoint to obtain a first rotation radian of the sub-map at the viewpoint.

[0008] S4. The rotation arcs of the remaining sub-maps connected to the sub-map where the viewpoint is located are equal to the first rotation arc.

[0009] Preferably, the threshold is one meter.

[0010] Preferably, the radian floating-point calculation formula is 360 / 2πr, where r is the radius of the earth.

[0011] Preferably, the sub-maps are designed to form terrain using a multi-resolution pyramid model, and the global terrain data is divided into several data sub-packets for storage according to the number of the sub-maps during the pre-processing stage.

[0012] Preferably, the hardware device is a head-mounted helmet, AR glasses or naked-eye 3D projection equipment.

[0013] Preferably, in S3, the viewpoint is a point selected by the user on the spherical surface of the virtual spherical three-dimensional map through a finger, a mouse or a touch screen.

[0014] The benefits of the present invention lie in that it uses actual longitude and latitude lines to divide the sphere of a virtual spherical three-dimensional map into several sub-maps. When rotating and zooming the map under high-precision conditions, it is only necessary to calculate the rotation radius of the sub-map where the current viewpoint is located, and then make the rotation radius consistent with other adjacent sub-maps. The jitter error between each sub-map is small and difficult for the human eye to detect, which greatly improves the user experience. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 The flowchart of a method for eliminating jitter in a global three-dimensional map system according to one embodiment is shown. DETAILED DESCRIPTION

[0016] To make the above-mentioned objects, features, and advantages of the present invention more readily apparent, specific embodiments of the present invention are described in detail below with reference to the accompanying drawings. The following description sets forth numerous specific details to facilitate a full understanding of the present invention. However, the present invention can be implemented in many other ways than those described herein, and those skilled in the art may make similar modifications without departing from the scope of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0017] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be an intermediate element. When an element is referred to as being "connected to" another element, it may be directly connected to the other element or there may be an intermediate element. The terms "vertical," "horizontal," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only implementation methods.

[0018] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which the present invention pertains. The terms used herein in the specification of the present invention are for the purpose of describing specific embodiments only and are not intended to limit the present invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0019] like Figure 1 As shown, a method for eliminating jitter in a global three-dimensional map system includes the following steps:

[0020] S1, using hardware equipment to project and establish a virtual spherical three-dimensional map in real space;

[0021] S2, with the center of the virtual spherical three-dimensional map as the center, forming a plurality of origin coordinates according to the intersection of integer longitude and latitude lines on the sphere, and positioning a sub-map on the spherical surface of the virtual spherical three-dimensional map using four adjacent origin coordinates;

[0022] S3, the virtual spherical three-dimensional map is zoomed and displayed with the center of the sphere as the initial origin. When the sub-map is rotated in a zoomed state with a resolution accuracy less than a threshold, a radian floating-point operation is performed using the coordinates of the origin closest to the viewpoint to obtain a first rotation radian of the sub-map at the viewpoint.

[0023] S4. The rotation arcs of the remaining sub-maps connected to the sub-map where the viewpoint is located are equal to the first rotation arc.

[0024] First, during use, the user projects an initial virtual spherical 3D map, similar to a sphere, into real space through a hardware device. The user adjusts the virtual spherical 3D map's position in real space through gestures or by directly manipulating buttons on the hardware device. The user also zooms in and out and rotates the virtual spherical 3D map to facilitate viewing of the target submap within the virtual spherical 3D map. Zooming, as it happens, magnifies the entire virtual spherical 3D map. Beyond a certain magnification limit, a small portion of the virtual spherical 3D map's surface is displayed to the user, while the remaining portion disappears into the background, appearing as a flat sandbox. Rotation only displays these portions separately, reducing pressure on the computer's GPU.

[0025] Furthermore, because the virtual spherical 3D map simulates the entire Earth, radians are generally used to describe the Earth's rotation during rotation. When the virtual spherical 3D map is enlarged, the resolution accuracy of the flat sandbox-like sub-maps on its surface reaches below the meter level, and the radian accuracy requirements will be very high. Therefore, we divide the virtual spherical 3D map into 360*180 sub-maps based on integer longitude and latitude. When using it, users will only experience map accuracy jitter when the resolution of the sub-map they are observing reaches below the meter level. The jitter problem is caused by the fact that the radians of two adjacent blocks are close, and when the computer calculates, due to the large radius of the Earth, the radians calculated between adjacent sub-maps vary greatly, so jitter will occur when moving continuously. In order to fix the jitter problem caused by rotation below this threshold, this technical solution uses the intersection of longitude and latitude to obtain several origin coordinates. After selecting the viewpoint, the origin coordinate closest to the viewpoint is rotated to perform radian floating-point operations to obtain the first rotation radian of the sub-map where the current viewpoint is located. The remaining 8 sub-maps in the nine-square grid that are close to this sub-map do not need to repeat the radian floating-point operations. The first rotation radian is directly used as their own rotation radian, thereby avoiding the computing pressure of the computer GPU and having little dependence on the computer CPU and GPU. Moreover, because the rotation radians are consistent, there will be no jitter problem between the nine-square grid sub-maps, and the user experience is better when observing.

[0026] Those skilled in the art will appreciate that, for example, if the Earth model needs to be rotated 1 meter from the surface, using radians is sufficient: by definition, one rotation is 2πr / r = 2π, and 360° = 2π radians. The Earth's circumference at the equator is 40,076 kilometers, so 360 / 40,076,000 meters = 0.000008.982932428 radians. This precision exceeds the accuracy of computer floating-point arithmetic, not to mention that rotating the Earth in decimeters or smaller units would yield even higher precision. Due to the precision of computer floating-point arithmetic, submaps are inconsistent during rotation, resulting in jitter when moving continuously. In this case, the submap closest to the current visible point is selected as a reference. The rotation radius generated by the computer floating-point calculation for this submap is then applied to all other submaps (when the mouse is released during a drag operation). This allows for correcting the floating map, as the required calculations are minimal. Consequently, the reliance on the computer's CPU and GPU is minimal.

[0027] Specifically, the submaps are designed using a multi-resolution pyramid model to create terrain. During the preprocessing phase, global terrain data is divided into several data sub-packets for storage based on the submaps. Initially, the virtual spherical 3D map is spherical, and the submaps are low-resolution. They are displayed on the surface of the virtual spherical 3D map using textures or other methods. As the virtual spherical 3D map is enlarged, the submaps' resolution gradually increases, creating a pyramid-like multi-resolution model design that reduces GPU stress. Multi-resolution is a common mapping technique and will not be discussed further here.

[0028] Specifically, the hardware device is a head-mounted helmet, AR glasses or naked-eye 3D projection equipment.

[0029] Specifically, the viewpoint is a point selected by the user on the spherical surface of the virtual spherical three-dimensional map using a finger, mouse or touch screen. After the user clicks and holds the viewpoint, he or she can drag the mouse or slide his or her finger to select a sub-map and the target area to be observed.

[0030] The above-described embodiments merely illustrate several implementations of the present invention, and while their descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent. It should be noted that a person skilled in the art would be able to make numerous variations and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the patent for this invention shall be determined by the appended claims.

Claims

1. A method for eliminating jitter in a global three-dimensional map system, characterized by: The following steps are included: S1, using hardware equipment to project and establish a virtual spherical three-dimensional map in real space; S2, with the center of the virtual spherical three-dimensional map as the center, forming a plurality of origin coordinates according to the intersection of integer longitude and latitude lines on the sphere, and positioning a sub-map on the spherical surface of the virtual spherical three-dimensional map using four adjacent origin coordinates; S3, the virtual spherical three-dimensional map is scaled and displayed with the center of the sphere as the initial origin. When the sub-map is rotated in a scaled state with a resolution accuracy less than a threshold, a radian floating-point operation is performed with the coordinates of the origin closest to the viewpoint. The radian floating-point operation formula is 360 / 2πr, where r is the radius of the earth, to obtain a first rotation radian of the sub-map at the viewpoint. S4. The rotation arcs of the remaining sub-maps connected to the sub-map where the viewpoint is located are equal to the first rotation arc.

2. The method for eliminating jitter in a global three-dimensional map system according to claim 1, wherein: The threshold is one meter.

3. The method for eliminating jitter in a global three-dimensional map system according to claim 1, wherein: The sub-maps are designed using a multi-resolution pyramid model to form the terrain, and the global terrain data is divided into several data sub-packets for storage according to the number of the sub-maps in the pre-processing stage.

4. The method for eliminating jitter in a global three-dimensional map system according to claim 1, wherein: The hardware device is a head-mounted helmet, AR glasses or naked-eye 3D projection equipment.

5. The method for eliminating jitter in a global three-dimensional map system according to claim 1, wherein: In S3, the viewpoint is a point selected by the user on the spherical surface of the virtual spherical three-dimensional map through a finger, a mouse or a touch screen.

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