Editing control method and device of dental model and method of displaying dental margin line

Abstract

This invention discloses an editing control method for a tooth model. The method includes: acquiring a tooth model and its tooth segmentation information, wherein the tooth segmentation information is used to identify multiple tooth regions in the tooth model; determining a target tooth position according to a current editing operation instruction, and determining the target tooth and at least one adjacent tooth adjacent to the target tooth according to the tooth segmentation information; acquiring a current viewing angle, and determining at least a portion of the adjacent tooth regions that occlude the editable region of the target tooth as the region to be processed according to the orientation relationship between the current viewing angle and the target tooth; adjusting the display parameters and editing attributes of the region to be processed so that the editable region of the target tooth position is visible under the current viewing angle, and configuring the region to be processed to not respond to editing operations targeting the region to be processed. This eliminates occlusion during editing and improves editing accuracy.

Description

Technical Field

[0001] This invention relates to the field of three-dimensional model editing technology, and in particular to a method and device for editing and controlling a tooth model, and a method for displaying tooth edge lines. Background Technology

[0002] In the digital dental restoration design process, users need to import a three-dimensional dental mesh model obtained through intraoral scanning or model scanning, and mark key geometric elements such as the preparation margin line on the target teeth to facilitate the subsequent generation of tissue surfaces for restorations such as crowns, bridges, inlays, and veneers. The accuracy of the margin line directly determines the marginal fit of the restoration and the clinical restoration quality. It is usually represented by several control points and their fitted curves. Users can edit and correct the margin line by adding, deleting, and dragging control points.

[0003] Existing edge line editing methods typically display the complete mesh of the target tooth and its adjacent teeth directly in a 3D dental arch mesh model. Users edit the edge lines by rotating and zooming the viewing angle and using the mouse to pick control points. This method works fine for edge segments located in the buccal-lingual direction of the dental arch; however, for edge segments on the mesial or distal surfaces, because adjacent teeth are close to the target tooth, users usually need to rotate the viewing angle to observe the target tooth from the mesial or distal direction. However, at this point, the adjacent teeth are precisely located between the viewing angle and the target tooth, obscuring the visual presentation of the edge line. Furthermore, because the 3D mesh of the adjacent teeth is in front of the target tooth, it preempts the mouse ray picking, making it impossible for users to accurately click and drag the edge line control points of the target tooth, thus making precise editing of mesial and distal edge segments difficult. Summary of the Invention

[0004] This invention provides an editing control method for a tooth model to solve the technical problem in the prior art where the area to be edited is difficult to observe and accurately edit due to occlusion by adjacent teeth during the edge line editing process of a three-dimensional dental mesh model.

[0005] In a first aspect, the present invention provides a method for editing and controlling a tooth model, comprising: Obtain a tooth model and its tooth segmentation information, wherein the tooth segmentation information is used to identify multiple tooth regions in the tooth model; The target tooth position is determined according to the current editing operation command, and the target tooth and at least one adjacent tooth adjacent to the target tooth are determined according to the tooth division information. Obtain the current observation viewpoint, and based on the positional relationship between the current observation viewpoint and the target tooth, determine at least a portion of the adjacent teeth that obstruct the area to be edited of the target tooth as the area to be processed; Adjust the display parameters and editing attributes of the area to be processed so that the area to be edited of the target tooth position is visible in the current viewing angle, and configure the area to be processed to not respond to editing operations on the area to be edited.

[0006] Secondly, the present invention also provides a method for displaying tooth edge lines without obstruction, comprising: Obtain a tooth model and identify the target tooth, the mesial adjacent teeth, and the distal adjacent teeth. Display the edge line of the target tooth, which is represented by at least one edge control point and its fitted curve. The edge control point is used in response to the user's editing operation. The camera's current viewing angle is acquired in real time, and the tooth located between the camera and the target tooth and facing the camera among the near-neighbor tooth and the far-neighbor tooth is identified as the rendering tooth; Perform transparent or semi-transparent rendering on the target tooth, and keep the target tooth and the other adjacent tooth among the mesial and distal adjacent teeth that are not identified as rendering teeth opaque, so that the outline and edge lines of the target tooth can be displayed without obstruction within the camera's visible area.

[0007] Thirdly, an electronic device is provided, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the steps of the above-described tooth model editing control method.

[0008] The visual presentation method for tooth design in this invention can automatically eliminate visual and interactive occlusion when editing areas on the target tooth that are easily obscured by adjacent teeth. Users can clearly see the area to be edited and perform editing operations directly and accurately, avoiding accidental selection of adjacent teeth. There is no need to manually hide or restore adjacent teeth, and the adjacency relationship reference is preserved, improving the accuracy and efficiency of editing. Attached Figure Description

[0009] Figure 1 A flowchart illustrating the editing control method for a tooth model provided in the first embodiment of the present invention; Figure 2 For the present invention Figure 1 A schematic diagram of the specific process of S120 in the editing control method of the tooth model shown; Figure 3 For the present invention Figure 1 The diagram shows the specific flow of S130 in the editing control method of the tooth model shown. Figure 4 For the present invention Figure 3 A schematic diagram of the specific process of S132 in the editing control method of the tooth model shown; Figure 5 For the present invention Figure 1 A schematic diagram of a specific process in S140 of the editing control method for the tooth model shown; Figure 6 For the present invention Figure 1 Another specific flowchart of S140 in the editing control method of the tooth model shown; Figure 7 for Figure 1 The diagram shows a portion of the teeth displayed in the normal viewing direction when the editing control method of the tooth model is applied. Figure 8 This is a schematic diagram showing a portion of the teeth from the current viewing angle in the mesiodistal direction. Figure 9 This is a schematic diagram showing a portion of the teeth after the current viewing angle is in the mesiodistal direction and obstructions have been removed. Figure 10 A flowchart illustrating the editing control method for a tooth model provided in the second embodiment of the present invention; Figure 11 This is a schematic diagram showing the edge lines during rendering; Figure 12 This is a schematic diagram of the structure of an electronic device provided in an embodiment of the present invention. Detailed Implementation

[0010] To enable those skilled in the art to more clearly understand the purpose, technical solution, and advantages of the present invention, the present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0011] The tooth model editing control method provided by this invention determines the target tooth and adjacent teeth by acquiring the tooth model and its segmentation information. It then determines occlusion based on the current viewing angle and the orientation relationship of the target tooth, and dynamically adjusts the display parameters and editing attributes of the occluded area to be processed. This actively eliminates occlusion between adjacent teeth, eliminating both visual and interactive occlusion, allowing users to precisely edit the area to be edited on the target object. This method has good scene adaptability and can be effectively applied to the visual presentation and editing of key geometric elements in digital dental restoration design, such as tooth preparation margins, marker points, and other key geometric elements requiring precise operation in environments with adjacent tooth occlusion. The invention will be described in detail below through specific embodiments.

[0012] Reference Figure 1 , Figure 1 This is a flowchart illustrating the editing control method for a tooth model provided in the first embodiment of the present invention. As shown in the figure, the method includes the following steps S110-S140: S110. Obtain the tooth model and its tooth segmentation information. The tooth segmentation information is used to identify multiple tooth regions in the tooth model.

[0013] In this invention, the tooth model can be a three-dimensional dental grid model obtained through intraoral scanning, model scanning, etc., usually represented in the form of a triangular mesh, containing the tooth surface geometry such as the crown and root of multiple teeth; while the tooth segmentation information contains information on multiple tooth regions in the tooth model. Preferably, each tooth region can correspond to the mesh data of one tooth, and the tooth segmentation information can also include the tooth position number corresponding to each tooth region, such as the tooth position number of the World Dental Federation (FDI).

[0014] In this step, a 3D dental arch mesh model and its tooth segmentation information can be directly received. The tooth segmentation information can be obtained by performing tooth segmentation processing on the 3D dental arch mesh model. This tooth segmentation processing divides the 3D dental arch mesh model into several subsets of individual tooth meshes, and each tooth can be assigned a tooth position number. Specifically, this tooth segmentation processing can be automatically executed using a deep learning-based tooth instance segmentation algorithm, or it can be obtained based on manual annotation or manual correction. For example, the user can mark tooth boundaries on the 3D dental arch mesh model, and the system will generate tooth segmentation information based on the user's annotations.

[0015] S120. Determine the target tooth position according to the current editing operation command, and determine the target tooth and at least one adjacent tooth adjacent to the target tooth according to the tooth division information.

[0016] In this invention, the target tooth position refers to the location identifier of the tooth targeted by the current editing operation command within the dental arch, such as a tooth position number. The current editing operation command refers to the instruction information generated by the human-computer interface in response to the user's operation when the user performs an editing operation on the target tooth in a 3D scene, used to indicate the target tooth to be edited. Specifically, the current editing operation command can be issued in the following ways: directly clicking or selecting the mesh model of the target tooth in the 3D scene; or selecting the tooth position number of the target tooth in the tooth position list or dental arch diagram; or entering the editing mode of the target tooth through a function button or shortcut key. In this embodiment, the current editing operation command at least includes the tooth position number of the target tooth it indicates, thereby determining the target tooth position. For example, when the user enters the tooth preparation edge line editing mode for a certain tooth, the tooth position of that tooth is the target tooth position.

[0017] In this step, after determining the target tooth position, the corresponding tooth region and adjacent teeth are determined based on the correspondence between tooth position numbers and tooth regions in the tooth segmentation information. In this embodiment, adjacent teeth are at least one tooth region on the dental arch that is adjacent to the target tooth region.

[0018] Specifically, such as Figure 2 As shown, step S120 may include the following steps S121-S122: S121. Determine the target tooth position according to the current editing operation command, and determine the tooth area in the tooth segmentation information that corresponds to the target tooth position as the target tooth.

[0019] In this step, the target tooth to be edited is determined based on the current editing operation instructions and tooth segmentation information, so as to facilitate subsequent identification of adjacent teeth.

[0020] S122. Based on the tooth position numbering order and spatial adjacency relationship of each tooth region in the tooth segmentation information, determine at least one of the mesial adjacent teeth and distal adjacent teeth of the target tooth as the adjacent teeth.

[0021] In this step, the adjacent teeth of the target tooth on the dental arch are determined based on the tooth position numbering order of each tooth region in the tooth segmentation information and the spatial adjacency relationship of the tooth regions on the dental arch. In this embodiment, the mesial adjacent teeth located on the mesial side of the target tooth and / or the distal adjacent teeth located on the distal side of the target tooth can be determined as adjacent teeth. It is understood that when the target tooth is located at the end of the dental arch or there is a missing tooth, the adjacent teeth on the corresponding side can be empty.

[0022] S130. Obtain the current observation viewpoint, and based on the orientation relationship between the current observation viewpoint and the target tooth, determine at least a portion of the adjacent teeth that obstruct the area to be edited from the target tooth as the area to be processed.

[0023] In this embodiment, changes in the viewing angle are monitored in real time. For example, during the process of editing the virtual camera viewpoint in a 3D scene by rotating, translating, and scaling the viewpoint, the current viewing angle is acquired in real time. The current viewing angle may include information such as the virtual camera position (i.e., the current viewing position) and the line-of-sight vector.

[0024] Specifically, such as Figure 3 As shown, in step S130, based on the current viewing angle and the orientation relationship between the target tooth and the target tooth, at least a portion of the adjacent teeth that obstruct the area to be edited from the target tooth are identified as the area to be processed, including the following steps S131-S133: S131. Based on the current observation perspective, determine the line of sight from the current observation position to the area to be edited of the target tooth.

[0025] In this invention, the area to be edited is the area on the target tooth that the user currently needs to edit, such as the tooth preparation edge line and its control points, marker points, or other feature geometry.

[0026] Specifically, in this step, the position information of the current observation position and the area to be edited is obtained; then, the line of sight is determined with the target point on the current observation position and the target point on the area to be edited as the starting point and the ending point, respectively; wherein, the target point on the area to be edited includes at least one of the center point, control point or geometric centroid of the area to be edited.

[0027] S132. Determine whether the adjacent teeth are located on the line of sight and between the current observation position and the target tooth.

[0028] In this embodiment, the area to be edited is taken as the edge line of the tooth preparation. In this step, it can be determined whether the current observation direction is normal or mesiodistal. Specifically, when adjacent teeth are not on the visual path, or, although on the visual path, are located on the side of the target tooth furthest from the current observation position, it is determined that the current observation direction is normal, and in this case, adjacent teeth do not obstruct the area to be edited on the target tooth. When adjacent teeth are on the visual path and located between the current observation position and the target tooth, it is determined that the current observation direction is mesiodistal, and in this case, adjacent teeth obstruct the area to be edited on the target tooth. The mesiodistal observation direction refers to the visual direction from the mesioadjacent direction of the target tooth to the distal adjacent direction.

[0029] like Figure 4 As shown, step S132 specifically includes the following steps S1321-S1322: S1321. Calculate the angle between the direction of the line of sight and the mesiodistal axis of the target tooth.

[0030] In this embodiment, the mesiodistal axis can be a vector pointing from the mesio-adjacent direction of the target tooth to the distal-adjacent direction. Specifically, based on the geometric information of the tooth regions corresponding to the target tooth and adjacent teeth, such as the centroid coordinates of each tooth mesh, the unit vector pointing from the centroid of the mesio-adjacent tooth to the centroid of the target tooth can be determined as the mesio-adjacent direction, and the unit vector pointing from the centroid of the target tooth to the centroid of the distal-adjacent tooth can be determined as the distal-adjacent direction. The composite vector of the mesio-adjacent and distal-adjacent directions, or the direction vector pointing from the mesio-adjacent region to the distal-adjacent region, is then used as the mesiodistal axis. When there are no adjacent teeth on one side of the target tooth, the system determines the mesio-adjacent or distal-adjacent direction based on the extension direction of the dental arch curve on that side, thereby obtaining the mesiodistal axis.

[0031] In this step, the angle between the current viewing angle and the mesiodistal axis of the target tooth can be calculated based on the virtual camera parameters under the current viewing angle. Specifically, the position coordinates P_cam of the virtual camera in the world coordinate system and the center point coordinates P_target of the current target tooth can be obtained in real time. The vector V = P_target - P_cam is used as the current viewing direction vector and normalized. The dot product between the normalized viewing direction vector and the unit vector of the mesiodistal axis is calculated, and the absolute value of the dot product is taken as the inverse cosine to obtain the angle between the direction of the viewing path and the mesiodistal axis.

[0032] S1322. Determine whether the included angle is within the preset threshold range, so as to determine whether the adjacent teeth are located on the line of sight and between the current observation position and the target tooth.

[0033] In this step, when the included angle enters the preset threshold range, it is determined that the adjacent tooth is located between the current observation view and the target tooth, and causes occlusion of the area to be edited. At this time, it is in the near-far-middle observation direction.

[0034] In this embodiment, the included angle includes a first included angle and a second included angle. Specifically, the first included angle between the direction of the observation line and the mesiodistal axis, and the second included angle between the direction of the observation line and the opposite direction of the mesiodistal axis are calculated. If the first included angle is less than or equal to a first preset threshold, it is determined that the current observation state is towards the distal side, and the adjacent tooth causing the occlusion is the distal adjacent tooth; if the second included angle is less than or equal to a second preset threshold, it is determined that the current observation state is towards the mesio side, and the adjacent tooth causing the occlusion is the mesio adjacent tooth. In other words, in the mesiodistal observation direction, if the direction of the observation line is closer to the mesio side, the mesio adjacent tooth is determined to be the adjacent tooth causing the occlusion; if the direction of the observation line is closer to the distal side, the distal adjacent tooth is determined to be the adjacent tooth causing the occlusion.

[0035] It should be noted that the first preset threshold and the second preset threshold can be set to the same angle value (e.g., 35°), or they can be set to different angle values ​​according to tooth position differences or user preferences. When the two take the same value, they are equivalent to a unified preset threshold. This preset threshold is the direction determination threshold. At this time, the occlusion side can be determined by comparing the angle between the line of sight and the near-distal axis and the angle in the opposite direction.

[0036] S133. When the determination is yes, based on the spatial occlusion relationship between adjacent teeth and the area to be edited, determine at least a portion of the adjacent teeth that occlude the area to be edited of the target tooth, and use this portion as the area to be processed.

[0037] In this invention, the area to be processed can be the entire tooth area of ​​an adjacent tooth, or it can be the part of an adjacent tooth that is being obscured.

[0038] To more accurately determine the area to be processed, this embodiment further incorporates occlusion detection to improve accuracy. Specifically, the spatial occlusion relationship between adjacent teeth and the area to be edited is detected. Based on the detection results, at least a portion of the adjacent teeth that occludes the area to be edited is identified as the area to be processed. The spatial occlusion relationship is detected by: detecting whether the projections of adjacent teeth on the screen space at least partially overlap with the projection of the area to be edited; and / or detecting whether adjacent teeth are located between the target tooth and the current observation position in the depth direction. Only when occlusion is determined to exist based on the detection results is the corresponding tooth area identified as the area to be processed.

[0039] It is understandable that when only a local area of ​​an adjacent tooth is located on the line of sight and obscures the area to be edited, only the mesh area on the obscured side (such as the mesial or distal surface of the adjacent tooth) is identified as the area to be processed, while the other areas of the adjacent tooth are displayed normally, so as to maintain as many adjacency references as possible.

[0040] Based on the above steps S131-S133, based on the spatial relative positional relationship between the target tooth and adjacent teeth, and combined with the current observation view, it is determined whether the adjacent teeth are located on the line of sight of the area to be edited under the current observation view and cause occlusion of the area to be edited of the target tooth; if so, the occluded tooth area among the adjacent teeth is further determined by combining screen occlusion detection and / or depth detection, thereby determining the area to be processed.

[0041] S140. Adjust the display parameters and editing attributes of the area to be processed so that the area to be edited in the target tooth position is visible in the current viewing angle, and configure the area to be processed to not respond to editing operations on the area to be edited.

[0042] In this invention, display parameters refer to parameters that affect the visual presentation of an object. Adjusting display parameters can include methods such as adjusting opacity, partial cropping, outline display, fade-out, and wireframe display, as long as they do not obscure the area to be edited or intercept the editing operation. Editing attributes can include picking attributes, etc.

[0043] In this embodiment, the preferred display parameter is opacity. After determining that there is an area to be processed, the opacity of the area to be processed is reduced to make it transparent or semi-transparent, thereby eliminating the occlusion of the area to be edited on the target tooth and making the area to be edited on the target tooth visible from the current viewing angle. Preferably, the opacity of the area to be processed can also be adjusted according to changes in the current viewing angle so that the opacity of the area to be processed transitions continuously with changes in the current viewing angle.

[0044] Specifically, such as Figure 5 As shown, adjusting the display parameters of the area to be processed in step S140 specifically includes the following steps S141a-S143a: S141a. When the angle between the current viewing angle and the mesiodistal axis of the target tooth is less than or equal to the second threshold, the opacity of the area to be processed is adjusted to the minimum opacity.

[0045] S142a. When the included angle is greater than the second threshold and less than the first threshold, the opacity of the area to be processed changes continuously and smoothly between the minimum opacity and the opacity.

[0046] S143a When the included angle reaches the first threshold, the area to be processed is canceled and restored to opaque.

[0047] In the above steps S141a-S143a, the second threshold and the first threshold are the entry transparency threshold and the exit transparency threshold, respectively, and the first threshold is greater than the second threshold. This is used to determine the degree to which the current viewing direction deviates from the near-far central axis, so as to determine the transparency value of the area to be processed, thereby making the opacity of the area to be processed continuously transition with the angle between the viewing direction and the near-far central axis.

[0048] Specifically, when the included angle is greater than or equal to the first threshold, it is determined to be the normal viewing direction, and adjacent teeth remain completely opaque. When the included angle is less than or equal to the second threshold, the area to be processed can be set to completely transparent, that is, the opacity of the area to be processed is adjusted to the minimum opacity. When the included angle is between the first and second thresholds, the opacity of the area to be processed is interpolated with the angle between the minimum opacity and opacity, such as setting the opacity of the area to be processed to interpolate between values ​​of 0.1 and 1 with the angle. This allows the area to be processed to smoothly transition from normal display to a transparent state, avoiding visual abrupt changes.

[0049] In this embodiment, the absolute values ​​of the second threshold and the first threshold can be 15° and 35°, respectively. It is understood that the above values ​​are merely preferred examples of this embodiment, and the values ​​of the first and second thresholds can be adaptively adjusted according to the crown height or user preference.

[0050] Understandably, the aforementioned perspective-driven transparency transition mechanism adapts to the perspective by adjusting the transparency of adjacent teeth, ensuring that the target tooth and its editable area remain clearly visible. This achieves adaptive control of the visual presentation of the 3D model, thereby improving the visual presentation of the tooth design.

[0051] It should be noted that the direction determination threshold used to determine whether the current viewing direction is closer to the near-middle side or the far-middle side can be the same as the exit transparency threshold (e.g., both are 35°). In this case, when the viewing angle enters the near-far-middle viewing direction, the occluded area to be processed is simultaneously identified and begins to become transparent. However, it should be understood that the exit transparency threshold and the direction determination threshold are independent parameters, and their values ​​can be configured independently according to actual needs. There is no necessary numerical equivalence between the two.

[0052] Furthermore, in this invention, while the areas to be processed of adjacent teeth are made transparent, the editing attributes of the areas to be processed are adjusted in a coordinated manner, so that the areas to be processed do not participate in the editing operations of the areas to be edited.

[0053] In this embodiment, taking the picking attribute as an example, the steps for adjusting the editing attributes of the area to be processed are described in detail: Specifically, such as Figure 6 As shown, adjusting the editing attributes of the area to be processed in step S140 specifically includes the following steps S141b-S142b: S141b When the opacity of the area to be processed is lower than the preset picking threshold or enters a transparent state, the area to be processed is excluded from the candidate set of editing rays so that the editing ray can penetrate the area to be processed and act on the area to be edited of the target tooth.

[0054] S142b: When the opacity of the area to be processed reaches the preset picking threshold, the area to be processed is re-included in the editing ray picking candidate set.

[0055] Based on steps S141b-S142b, when the opacity of the area to be processed is lower than the picking threshold or enters a transparent state, the area to be processed is removed from the candidate set of editing rays. In this way, the editing ray (e.g., a mouse ray) can penetrate the area to be processed and directly act on the area to be edited of the target tooth. Users can accurately click and drag control points on the area to be edited without accidentally selecting adjacent teeth, thereby improving the accuracy and efficiency of model editing.

[0056] In some other embodiments, adjusting the editing attributes of the area to be processed in step S140 may specifically include: marking the area to be processed as unpickable when the opacity of the area to be processed is lower than a preset picking threshold or enters a transparent state, so that the editing ray can penetrate the area to be processed and act on the area to be edited of the target tooth; and canceling the unpickable marking of the area to be processed when the opacity of the area to be processed reaches the preset picking threshold.

[0057] Based on the above step S140, when the current viewing angle is in the near-far-medium viewing direction, the opacity of the area to be processed in the adjacent teeth is reduced, and at the same time, it is controlled not to respond to the editing operation of the area to be edited. This eliminates visual occlusion and interactive occlusion, allowing the user to accurately operate on the area to be edited of the target object. Under the normal viewing direction, the area to be processed can be automatically restored to opaque display, and the area to be processed can participate in the editing operation of the area to be edited, so that the adjacent teeth can maintain the original display parameters and editing attributes.

[0058] Using the edge line of tooth 46 (lower right first molar) in the tooth model as the area to be edited, the visual presentation method for tooth design in this invention first acquires the mandibular intraoral scanned dentition mesh model and its tooth segmentation information. The tooth segmentation information includes the tooth regions corresponding to teeth 45, 46, 47, etc., and is labeled with FDI tooth position numbers. After the user clicks to enter the edge line editing mode for tooth 46, this invention determines the target tooth position as 46 based on the tooth position number targeted by the generated current editing operation command, determines the target tooth region corresponding to tooth 46 based on the tooth segmentation information, and determines the mesial adjacent tooth 45 and distal adjacent tooth 47 based on the tooth position number order and spatial adjacency relationship; at the same time, based on the geometric information such as the centroid and adjacent contact area position of each tooth region, the mesiodistal axis pointing from the mesial adjacent direction of tooth 46 to the distal adjacent direction is calculated.

[0059] Furthermore, the system calculates the angle between the line of sight and the near-to-mid axis in real time. When the user is observing normally in the cheek-tongue direction and editing the cheek and tongue side edge lines, if the angle does not fall within the preset threshold range, it is determined to be a normal observation state (e.g., ...). Figure 7 As shown), teeth 45, 46, and 47 are all displayed normally and opaquely, and participate in the editing ray picking. When the user rotates the current viewing angle to observe tooth 46 from the mesial direction to edit the mesial edge line, the calculated angle falls within the preset threshold range, determining that the current viewing direction is mesial to farsial (e.g., Figure 8 As shown in the image, tooth 45 is identified as the tooth causing occlusion between the current observation position and tooth 46. Based on the spatial occlusion relationship between tooth 45 and the area to be edited, and combined with occlusion detection, the tooth region that is occluding tooth 46 is identified as the area to be processed. Subsequently, the opacity of the area to be processed for tooth 45 is dynamically reduced with the rotation of the viewing angle until the minimum opacity is reached, making the mesial edge line of tooth 46 clearly visible (as shown in the image). Figure 9 (As shown); at the same time, the area to be processed is excluded from the candidate set of editing rays, so that when the user picks the 46 teeth mid-edge control point, the editing ray penetrates the transparent area and reaches the target directly, avoiding misselection.

[0060] When the user rotates the viewing angle back to the normal direction, the invention detects that the included angle has deviated from the preset threshold range, automatically restoring the area to be processed in tooth 45 to opaque and re-including it in the candidate set for editing rays. Similarly, when viewing tooth 46 from a distal perspective to edit the distal edge segment, tooth 47 is made transparent and processed for penetration. Furthermore, after picking, subsequent editing operations such as adding, deleting, or dragging edge line control points can be performed. After editing, the edge line data of tooth 46 is saved for use in downstream processes such as crown restoration tissue surface generation. Through this method, when editing edge lines on target teeth that are easily obscured by adjacent teeth, users do not need to manually hide adjacent teeth, and will not be obscured or mispicked by adjacent teeth, thus accurately completing the editing operation, improving the accuracy and efficiency of editing.

[0061] In summary, the tooth model editing control method of this embodiment utilizes the tooth segmentation information of the three-dimensional dental mesh model to identify the target tooth and its adjacent teeth. Based on the spatial relative position of the target tooth and the current viewing angle, it automatically and dynamically adjusts the display parameters and editing attributes of adjacent tooth regions that are located on the line of sight of the current viewing angle and the area to be edited and that obscure the target tooth. This eliminates visual and interactive occlusion during editing of the area to be edited. Furthermore, under normal viewing direction, all adjacent teeth can maintain normal display and editing operations, and the user can still refer to the adjacency relationship. The entire transparency process is automatic with the viewing angle, without the need for the user to manually hide and restore adjacent teeth. Thus, while preserving the adjacency relationship reference, it improves the accuracy and efficiency of editing the area to be edited (such as the mesial and distal edge lines) and reduces the user's operational burden.

[0062] Reference Figure 10 , Figure 10 This is a flowchart illustrating the tooth model editing control method provided in the second embodiment of the present invention. As shown in the figure, in this embodiment, the method includes the following steps S210-S250: S210. Obtain the tooth model and its tooth segmentation information. The tooth segmentation information is used to identify multiple tooth regions in the tooth model.

[0063] This step is similar to step S110 above, and will not be repeated here.

[0064] S220. Determine the target tooth position according to the current editing operation command, and determine the target tooth and at least one adjacent tooth adjacent to the target tooth according to the tooth division information.

[0065] This step is similar to step S120 above, and will not be repeated here.

[0066] S230. Obtain the current observation viewpoint, and based on the orientation relationship between the current observation viewpoint and the target tooth, determine at least a portion of the adjacent teeth that obstruct the area to be edited from the target tooth as the area to be processed.

[0067] This step is similar to step S130 above, and will not be repeated here.

[0068] S240. Adjust the display parameters and editing attributes of the area to be processed so that the area to be edited of the target tooth position is visible in the current viewing angle, and configure the area to be processed to not respond to editing operations on the area to be edited.

[0069] This step is similar to step S140 above, and will not be repeated here.

[0070] S250: Renders the tooth model based on the preset drawing order and the current display parameters and editing attributes.

[0071] In this embodiment, the preset drawing order is as follows: target tooth, area to be processed, and area to be edited. Specifically, the opaque object is drawn first, then the transparent area to be processed is drawn, and finally the area to be edited is drawn, to ensure that the area to be edited is always clearly visible and displayed on top of the transparent area to be processed.

[0072] During the rendering process, depth testing is enabled for transparent areas to be processed to prevent transparent models from ignoring depth relationships and incorrectly floating to the foreground; at the same time, depth writing is disabled to ensure that subsequently drawn areas to be edited can still be displayed and blended normally.

[0073] In this step, when making the area to be processed transparent, this can be achieved by setting the vertex color opacity of the mesh, the material transparency, or by using a clipping plane, without affecting the display status of other areas of the tooth. Furthermore, it is preferable to use a double-sided rendering method for the area to be processed, drawing the back side first and then the front side, to avoid incorrect transparency ordering, the back side covering the front side, or abnormal local brightness and darkness.

[0074] For example, when the area to be edited is the edge line of a tooth preparation, first draw the opaque object such as the target tooth, then draw the transparent area to be processed, and finally draw the edge line to ensure that the edge line is always clearly visible and displayed on the transparent area to be processed, so that the user can accurately pick and drag the edge line control points and perform other editing operations.

[0075] Furthermore, in some embodiments, to facilitate observation of the geometric features of the area to be edited, the editing control method for the tooth model in this embodiment may further include: displaying the tooth model in a first display style (such as...) Figure 11 The blue control points (fitted curves) show the edge lines; based on a preset two-dimensional cutting plane, the edge lines are projected onto the two-dimensional cutting plane, and the projection lines of the edge lines on the two-dimensional cutting plane are displayed in a second display style (such as a gray shadow style) that is different from the first display style, so as to assist in observing the geometric features of the edge lines through the projection lines.

[0076] Understandably, the projection line is displayed at the projection position of the edge line onto the two-dimensional cutting plane, used to assist in observing the geometric features of the editing area. The two-dimensional cutting plane is typically set perpendicular to the current viewing direction (or parallel to the near-far axis) so that the user can observe the projection shape of the edge line on that specific cross-section from an orthogonal perspective. When the user drags the edge line control points, the projection line updates in real time as the edge line changes, continuously providing the user with depth and angle references.

[0077] This invention also provides an editing and control device for a tooth model, including a data access module, a target recognition module, a monitoring and determination module, an operation control module, and a rendering output module. Detailed descriptions of each functional module are as follows: The data access module is used to acquire the tooth model and its tooth segmentation information. The tooth segmentation information is used to identify multiple tooth regions in the tooth model. The target recognition module is used to determine the target tooth position based on the current editing operation command, and to determine the target tooth and at least one adjacent tooth adjacent to the target tooth based on the tooth division information; The monitoring and determination module is used to acquire the current observation view and, based on the orientation relationship between the current observation view and the target tooth, to determine at least a portion of the adjacent teeth that obstruct the area to be edited from the target tooth as the area to be processed. The operation control module includes a display control unit and an editing control unit, wherein... The display control unit is used to adjust the display parameters of the area to be processed so that the area to be edited of the target tooth position is visible from the current viewing angle; An editing control unit is used to adjust the editing properties of the area to be processed so that the area to be processed is configured not to respond to editing operations on the area to be edited. The rendering output module is used to render the tooth model based on a preset drawing order and the current display parameters and edit attributes.

[0078] This invention provides a method for displaying tooth edge lines without obstruction.

[0079] The tooth model is processed to determine the target tooth, the mesial adjacent teeth located on the mesial side of the target tooth and adjacent to the target tooth, and the distal adjacent teeth located on the distal side of the target tooth and adjacent to the target tooth. The mesial adjacent teeth, the target tooth, and the distal adjacent teeth are arranged sequentially along the dental arch.

[0080] In this embodiment, the tooth model is a three-dimensional dental grid model obtained through intraoral scanning or model scanning, which can be represented in the form of a triangular mesh. The target tooth, mesial adjacent teeth, and distal adjacent teeth are determined by the tooth segmentation results of the tooth model: the segmentation results divide the mesh of the tooth model into multiple mesh subsets corresponding to a single tooth, and assign a tooth position number (e.g., FDI tooth position number) to each mesh subset; the segmentation results may also include geometric reference information for each mesh subset, which includes at least one of the following: mesh centroid coordinates, adjacent contact area position, and tooth long axis direction. This segmentation result can be automatically generated by a deep learning-based tooth instance segmentation algorithm, or it can be obtained through manual annotation or manual correction.

[0081] Specifically, the target tooth can be determined based on the tooth position number of the edge line currently being edited, and the mesial and distal adjacent teeth can be determined according to at least one of the tooth position numbering sequence on the dental arch and the adjacent relationship in the mesh space. For example, if the edge line to be edited is located at tooth 46 (lower right first molar), the mesial adjacent tooth can be determined as tooth 45, and the distal adjacent tooth as tooth 47. Teeth 45, 46, and 47 are arranged sequentially along the dental arch, as follows... Figure 7 As shown.

[0082] It should be noted that when the target tooth is located at the end of the dental arch, or when there is a missing tooth on the corresponding side of the target tooth, the adjacent teeth on that side are empty. When the adjacent teeth on that side are empty, there is no need to perform transparent or semi-transparent rendering processing on the adjacent teeth on that side, and when the camera observes the target tooth from that side, the part of the edge line near that side is itself presented in an unobstructed state. In this case, the tangent direction of the dental arch arc fitted to each tooth on the dental arch at the target tooth, or the extension direction of the direction from the geometric center of the target tooth to the geometric center of the dental arch on the corresponding side, can be used as the mesial or distal direction axis for the missing tooth on that side, to participate in subsequent angle calculations, thereby ensuring that angle determination remains continuously usable at the end of the dentition and in the case of missing teeth.

[0083] Based on the camera's current viewing angle, the tooth located between the camera and the target tooth, facing the camera, is identified as the rendering tooth.

[0084] Specifically, this step may include: first, determining the mesial axis pointing from the target tooth to the mesial adjacent tooth, and the distal axis pointing from the target tooth to the distal adjacent tooth; second, using the directed line from the target tooth to the camera as the viewing angle line corresponding to the viewing angle; then calculating the angles between the viewing angle line and the mesial and distal axes respectively; when the angle between the viewing angle line and one of the axes is less than a preset angle threshold, it is determined that the camera is located on the side pointed to by that axis, and the adjacent tooth on that side is located between the camera and the target tooth and is determined to be the rendering tooth. Since this embodiment compares the viewing angle line from the target tooth to the camera with the axes pointing from the target tooth to the adjacent teeth on both sides, it can directly determine the side where the camera is located, avoiding the problem of not being able to distinguish between the mesial and distal sides when comparing with a non-directional axis and a single angle.

[0085] Furthermore, a first angle between the viewpoint line and the mesial direction axis, and a second angle between the viewpoint line and the distal direction axis can be calculated: when the second angle is less than a preset angle threshold and the first angle is not less than the preset angle threshold, it is determined that the camera is observing towards the distal adjacent tooth, and the tooth is rendered as the distal adjacent tooth; when the first angle is less than the preset angle threshold and the second angle is not less than the preset angle threshold, it is determined that the camera is observing towards the mesial adjacent tooth, and the tooth is rendered as the mesial adjacent tooth; when both the first and second angles are not less than the preset angle threshold, it is determined that the camera is in a normal observation state, and both the mesial and distal adjacent teeth remain opaque during rendering. For example, the preset angle threshold can be 35°.

[0086] In other embodiments, the mesiodistal axis can be used directly as a comparison reference: The mesiodistal axis is determined as a directed axis pointing from the contact area between the target tooth and its mesial neighbor to the contact area between the target tooth and its distal neighbor, or it is the bisector of the angle formed between the reverse extension of the mesiodistal axis between the target tooth and its mesial neighbor and the distal axis between the target tooth and its distal neighbor, with the positive direction of the mesiodistal axis pointing towards the side where the distal neighbor is located; the third angle between the viewing angle line and the mesiodistal axis is calculated. The camera is determined to be observing from the distance, and the fourth angle is calculated between the viewing angle line and the opposite direction of the near-to-far midline. When the third angle is less than a preset angle threshold and the fourth angle is not less than a preset angle threshold, the camera is determined to be observing from the far-to-mid side, and the rendered tooth is the distal neighbor tooth. When the fourth angle is less than a preset angle threshold and the third angle is not less than a preset angle threshold, the camera is determined to be observing from the near-to-mid side, and the rendered tooth is the mesial neighbor tooth. When both the third and fourth angles are not less than the preset angle thresholds, the camera is determined to be observing normally, and both the mesial neighbor and distal neighbor teeth remain opaque. This implementation unifies the observation determination on both sides to a comparison along the same near-to-far midline and its opposite direction, making the determination process simpler.

[0087] The determination of the mesial and distal axes can include any of the following methods: Method 1: Obtain the mesh centroids of the target tooth, the mesial adjacent tooth, and the distal adjacent tooth, and determine the direction from the mesh centroid of the target tooth to the mesh centroid of the mesial adjacent tooth as the mesial axis, and the direction from the mesh centroid of the target tooth to the mesh centroid of the distal adjacent tooth as the distal axis; Method 2: Determine the mesial contact area between the target tooth and the mesial adjacent tooth, and the distal contact area between the target tooth and the distal adjacent tooth, and determine the direction from the central region of the target tooth to the mesial contact area as the mesial axis, and the direction from the central region of the target tooth to the distal contact area as the distal axis. Furthermore, the mesial and distal axes can be the projection directions of the corresponding direction vectors onto the reference plane determined by the tooth long axis of the target tooth and the dental arch plane, so as to eliminate the component in the tooth long axis direction and make the angle determination only reflect the degree of observation along the mesial and distal directions of the dental arch; the mesial and distal axes can also be two opposite directions of the tangent of the dental arch arc fitted to each tooth on the dental arch at the target tooth.

[0088] To avoid mistakenly making adjacent teeth that are not occluded transparent based solely on angle judgment, this embodiment also combines occlusion detection to determine the rendering teeth when the smaller of the first and second included angles is less than a preset angle threshold. Specifically, the meshes of the mesial and distal adjacent teeth are projected onto the camera's screen space to obtain a first projection area corresponding to the mesial adjacent teeth and a second projection area corresponding to the distal adjacent teeth; the projection of at least a portion of the edge line segments closest to the mesial and / or distal adjacent teeth in the edge line into the screen space is determined to obtain the editing area; for each of the mesial and distal adjacent teeth, the overlap area or overlap ratio between its projection area and the editing area is calculated; when the overlap area or overlap ratio is greater than a preset area threshold, the adjacent tooth is determined as a rendering tooth and transparent or semi-transparent rendering is performed; when the overlap between the projection areas and the editing areas of both is not greater than the preset area threshold, the opaque rendering of the mesial and distal adjacent teeth is maintained.

[0089] Alternatively or additionally, occlusion relationships can be verified through depth comparison or ray testing: using the direction from the camera to the target tooth as the viewing direction, which is the opposite of the viewpoint line, the depth values ​​of the mesh surfaces of the mesial and distal adjacent teeth on the corresponding pixels in the editing area are compared one by one with the depth values ​​of the edge lines on the corresponding pixels. The number or percentage of pixels with depth values ​​less than the depth value of the edge line is counted. When the number or percentage of pixels exceeds a preset threshold, the corresponding adjacent tooth is determined to be in depth ahead of the target tooth and is designated as the rendered tooth; and / or, a test ray is emitted from the optical center of the camera to a point on the edge line of the target tooth that is close to the mesial or distal adjacent tooth. When the test ray hits the mesh surface of the mesial or distal adjacent tooth before hitting the mesh surface or edge line of the target tooth, the adjacent tooth that is hit first is designated as the rendered tooth.

[0090] Perform transparent or semi-transparent rendering on the target tooth, and keep the target tooth and the other adjacent tooth among the mesial and distal adjacent teeth that are not identified as the target tooth opaque, so that the outline of the target tooth and the edge lines arranged on the surface of the target tooth are displayed without obstruction within the camera's visible area.

[0091] In this embodiment, the edge line is represented by at least one edge control point and its fitted curve. This edge line is the tooth preparation edge line (shoulder edge line, cervical edge line), and the edge control points on it can be added, deleted, or dragged by the user. Transparent or semi-transparent rendering processing can be triggered when an edge line processing instruction is received. This edge line processing instruction is used to instruct the execution of edge line processing for the target tooth. When the edge line processing instruction is not received, both mesial and distal adjacent teeth remain opaque and can be picked up, thus maintaining consistency with the normal display during normal browsing, measurement, and other non-editing operations, and avoiding interference from the transparency of adjacent teeth on irrelevant operations.

[0092] Specifically, the opacity of the rendered tooth can be determined by the angle between the viewing line and the direction axis corresponding to the rendered tooth. The smaller the angle, the closer the camera is to observing the rendered tooth along the mesiodistal direction of the dental arch, the stronger the occlusion, and the lower the opacity of the rendered tooth. For example, an outer angle threshold, an inner angle threshold, and a minimum opacity can be preset, with the outer angle threshold being greater than the inner angle threshold: when the angle is not less than the outer angle threshold, the rendered tooth remains completely opaque; when the angle is not greater than the inner angle threshold, the opacity of the rendered tooth is reduced to the minimum opacity; when the angle is less than the outer angle threshold and greater than the inner angle threshold, the opacity of the rendered tooth transitions continuously between the minimum opacity and complete opacity with the angle. This continuous transition can be linear or smooth. For example, the outer angle threshold and the inner angle threshold can be 35° and 15°, respectively; the minimum opacity can be zero to render the rendered tooth completely transparent, or it can be a value greater than zero and less than one (e.g., 0.15) to allow the rendered tooth to retain its outline while being transparent, facilitating user reference to the dental arch shape and the positional relationship with adjacent teeth. Therefore, the transparency of adjacent teeth changes continuously with the viewing angle, avoiding abrupt changes in display; when the rendered tooth is a distal adjacent tooth, the direction axis for comparison is the distal direction axis, and when the rendered tooth is a mesial adjacent tooth, the direction axis for comparison is the mesial direction axis.

[0093] Furthermore, the angle range between the outer angle threshold and the inner angle threshold can form a transition zone, and this transition zone constitutes a hysteresis interval: when the included angle decreases from a direction not less than the outer angle threshold to fall within the transition zone, or not greater than the inner angle threshold, and this state continues for a first set duration (e.g., 0.3 s), the rendering tooth switches from an opaque state to a transparent or semi-transparent state; when the included angle increases from a direction not greater than the inner angle threshold to leave the transition zone, and this state continues for a second set duration (e.g., 0.5 s), the rendering tooth returns from a transparent or semi-transparent state to an opaque state; under any included angle value within the transition zone, the rendering tooth maintains its display state before the switch. Thus, the switching between transparent and opaque for the rendering tooth does not repeatedly occur due to viewing angle jitter, the display state is stable, and the first set duration and the second set duration can be the same or different.

[0094] It should also be noted that the mesh of each tooth in the tooth model is a closed surface mesh with volumetric hierarchy, rather than a single-layer surface model, and it has obvious front and back layers. For this type of mesh, when rendering teeth for transparency or semi-transparency, double-sided rendering can be enabled and single-pass rendering merging can be disabled. The back surface corresponding to the tooth can be rendered in two passes, first rendering the back surface corresponding to the tooth, and then rendering the front surface corresponding to the tooth. The back surface corresponding to the tooth drawn first serves as the bottom layer for color and shadow writing, and the front surface corresponding to the tooth drawn later is overlaid with a specular layer and a semi-transparent blending layer on top of this bottom layer. This keeps the global blending order of the rendered tooth consistent in multiple blending processes, avoids transparency sorting errors, back surface covering the front surface, or local brightness and darkness anomalies, and restores the full volume produced by the scattering of the semi-transparent enamel layer and dentin of the tooth.

[0095] In conjunction with transparent or semi-transparent rendering, the display order of edge lines within the visible area is defined, so that the edge control points on the edge lines are presented on the rendering teeth within the visible area.

[0096] Specifically, drawing order parameters are set for the rendered teeth, target teeth, and edge lines, with the drawing order determined primarily by the magnitude of these parameters. This prioritizes the drawing order parameters over the default sorting rule based on the distance from the object to the camera. For example, the drawing order parameter for the target teeth can be set to 0, the drawing order parameter for the rendered teeth to 1, and the drawing order parameter for the edge lines to 2. After collecting the objects to be drawn in each frame, the renderer prioritizes comparing the drawing order parameters, drawing the smaller values ​​first and the larger values ​​later. Then, the opaque objects, rendered teeth, and edge lines are drawn sequentially from first to last. The opaque objects include the target teeth (which are rendered opaquely) and another adjacent tooth. Because the drawing order parameter takes precedence over distance sorting, regardless of the camera's viewing angle or the spatial relationship between the edge lines and the target teeth or rendered teeth, the edge lines are always drawn after the rendered teeth, thus covering the pixels already drawn by the rendered teeth on the screen pixels and appearing as the outermost layer. Figure 9 As shown.

[0097] When drawing edge lines, a method of enabling depth testing and disabling depth writing is adopted. On the one hand, the depth value of each pixel of the edge line is compared with the depth value already written to the depth buffer by the opaque object. Pixels with depth values ​​greater than the corresponding depth values ​​in the depth buffer are discarded. This ensures that the edge line only appears on the visible surface of the target tooth facing the camera, without penetrating to the back or interior of the target tooth, thus preventing the edge line from deviating from the real occlusion relationship like an interface overlay. On the other hand, the depth value of the edge line is not written to the depth buffer. This ensures that the depth buffer only contains the depth information of geometry drawn opaquely with depth writing enabled (i.e., real geometry). This information is used for at least one of the following: semi-transparent blending of the tooth, post-processing rendering that relies on the depth map (such as ambient occlusion, depth of field, edge detection), and picking based on depth values ​​to calculate 3D coordinates. This avoids manual annotation lines contaminating the depth map, which can lead to image artifacts or coordinate calculation errors. In addition, disabling depth writing allows the edge line to blend smoothly with its background color, avoiding harsh breaks or white edges on the lines.

[0098] The edge line of the target tooth can be simultaneously displayed in a first graphic and a second graphic: the first graphic is a three-dimensional spatial line set on the surface of the tooth model and distributed along the cervical margin of the target tooth, such as control points and their fitted curves shown in blue, and the edge control points on the edge line are draggable control points on the first graphic; the second graphic is an orthographic projection of the first graphic onto a preset two-dimensional projection plane, such as displayed in a gray shadow style, which is a cross-sectional view plane associated with the edge line editing operation. In response to the editing operation of the edge control points on the first graphic, the first graphic is updated and the second graphic is updated synchronously, so that the user can observe the geometric features (such as depth and angle changes) of the edge line editing area through the second graphic. When the rendered tooth is subjected to transparent or semi-transparent rendering processing, both the first and second graphics are displayed without being obscured by the rendered tooth, and the second graphic is presented on the preset two-dimensional projection plane in the same display order as the edge line on the outermost layer.

[0099] In conjunction with transparent or semi-transparent rendering, the picking behavior of the mouse ray is limited so that edge control points on the edge line can be picked.

[0100] Specifically, when a rendering tooth is in a state of performing transparent or semi-transparent rendering processing, the rendering tooth is excluded from the candidate set for mouse ray picking, or the rendering tooth is set to be unpickable or pickable through. For example, the opacity of the rendering tooth in the current frame can be obtained; when the opacity is lower than a preset picking threshold (e.g., 0.5), the rendering tooth is excluded from the candidate set, or set to be unpickable or pickable through; when the opacity is not lower than the preset picking threshold, the rendering tooth is reintroduced into the candidate set and restored to its normal pickable state. Optionally, the preset picking threshold is greater than the opacity of the rendering tooth when it enters the transparent or semi-transparent rendering processing state, so that the rendering tooth is excluded from the candidate set when it switches from an opaque state to a transparent or semi-transparent state, and the edge control points can be picked in the same frame as the rendering tooth being made transparent, avoiding an intermediate state where it is visible but cannot be clicked.

[0101] The candidate set excluding rendered teeth allows the picking ray emitted from the mouse position to pass over the rendered tooth and hit the mesh surface of the target tooth and the edge control points on the edge line; the edge line is updated in response to dragging the hit edge control points. Thus, when the user turns to view in a mesiodistal direction, there is no need to manually hide adjacent teeth; the mesiodistal and distal edge segments of the target tooth can be clearly seen, and the edge control points can be directly and accurately clicked and dragged without mistakenly selecting the surface of adjacent teeth.

[0102] The display automatically recovers as the viewing angle changes, and the display and picking states are redefined based on interactive operations.

[0103] Specifically, when neither the mesial nor distal adjacent teeth are located between the camera and the target tooth, the camera's viewing angle is determined to return to the normal viewing direction. In response to this determination, the adjacent teeth that previously underwent transparent or semi-transparent rendering are automatically restored to opaque rendering, and their normal picking state is restored. This allows for reference to the adjacency relationship between the target tooth and the mesial and distal adjacent teeth from this viewing angle. Furthermore, this restoration does not depend on manual display settings performed by the user. Figure 7 As shown.

[0104] Meanwhile, the display order and candidate set defined in this embodiment are continuously updated with interaction: in response to any viewpoint processing operation such as rotation, translation, and scaling of the tooth model, and at least one editing operation such as adding, deleting, and dragging edge control points on the edge line, the rendered tooth is redefined according to the processed viewing perspective, and the display order of edge lines in the visible area and the candidate set for mouse ray picking are redefined, so that the edge lines remain visible and pickable at any viewpoint and at any editing moment. After editing, the edge line data of the target tooth is saved for use in subsequent downstream processes such as the generation of tissue surfaces for restorations such as crowns, bridges, inlays, and veneers.

[0105] In summary, the visual presentation method for tooth design in this embodiment determines the mesial adjacent teeth, target teeth, and distal adjacent teeth arranged sequentially along the dental arch based on the tooth segmentation results. According to the angle between the current viewing angle of the camera and the directional axis pointing from the target tooth to the adjacent teeth on both sides, only one adjacent tooth facing the camera and located between the camera and the target tooth is rendered as the transparent or semi-transparent tooth. The target tooth and the other adjacent tooth remain opaque, thus eliminating visual occlusion in the mesial and distal directions while preserving the adjacency relationship and dental arch morphology reference. Simultaneously, through display order constraints and candidate set constraints linked to the rendering process, edge lines and their edge control points are presented on the rendered teeth and can be directly picked, eliminating interactive occlusion. Furthermore, with the mechanism of automatically restoring display based on viewing angle and continuously updating with interaction, there is no need for the user to manually hide and restore adjacent teeth. The entire process is precisely triggered by tooth position and direction, avoiding the reduction of the target tooth's own recognizability as with global semi-transparency, and preventing transparent adjacent teeth from blocking mouse picking, significantly improving the accuracy and efficiency of mesial and distal edge line editing.

[0106] Reference Figure 12 , Figure 12 This is a schematic block diagram of an electronic device according to an embodiment of the present invention. As shown in the figure, the electronic device includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the steps of the method of any of the above embodiments. This electronic device can be a local design terminal such as a desktop computer, laptop computer, or workstation, or it can be a cloud server; this embodiment does not limit it in this way.

[0107] This invention also provides a computer-readable storage medium storing a computer program thereon, which, when executed by a processor, implements the steps of the method described in any of the above embodiments. The computer-readable storage medium may include various media capable of storing program code, such as a USB flash drive, a portable hard drive, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk.

[0108] It should be further noted that the descriptions of each embodiment in the above embodiments have different emphases. Parts not described in detail in a certain embodiment can be referred to in the relevant descriptions of other embodiments. For the foregoing method embodiments, for the sake of simplicity, they are all described as a series of actions. However, those skilled in the art should understand that the present invention is not limited to the described order of actions, because according to the present invention, some steps can be performed in other orders or simultaneously. Furthermore, those skilled in the art should also understand that the embodiments described in the specification are all preferred embodiments, and the actions and modules involved are not necessarily essential to the present invention.

[0109] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in the present invention, and these modifications or substitutions should all be covered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for editing and controlling a tooth model, characterized in that, include: Obtain a tooth model and its tooth segmentation information, wherein the tooth segmentation information is used to identify multiple tooth regions in the tooth model; The target tooth position is determined according to the current editing operation command, and the target tooth and at least one adjacent tooth adjacent to the target tooth are determined according to the tooth division information. Obtain the current observation viewpoint, and based on the positional relationship between the current observation viewpoint and the target tooth, determine at least a portion of the adjacent teeth that obstruct the area to be edited of the target tooth as the area to be processed; Adjust the display parameters and editing attributes of the area to be processed so that the area to be edited of the target tooth position is visible in the current viewing angle, and configure the area to be processed to not respond to editing operations on the area to be edited.

2. The method for editing and controlling a tooth model as described in claim 1, characterized in that, The step of determining at least a portion of the adjacent teeth that obstruct the area to be edited from the target tooth, based on the current viewing angle and the orientation relationship between the target tooth and the target tooth, as the area to be processed includes: Based on the current observation perspective, determine the line of sight path from the current observation position to the area to be edited of the target tooth; Determine whether the adjacent tooth is located on the line of sight and between the current observation position and the target tooth; When the determination is yes, at least a portion of the adjacent teeth located on the line of sight is identified as the area to be processed.

3. The method for editing and controlling a tooth model as described in claim 2, characterized in that, The step of determining whether the adjacent tooth is located on the line of sight and between the current observation position and the target tooth includes: Calculate the angle between the direction of the line of sight and the mesiodistal axis of the target tooth; Determine whether the included angle is within a preset threshold range, so as to determine whether the adjacent tooth is located on the line of sight and between the current observation position and the target tooth; The mesiodistal axis extends from the mesioadjacent direction of the target tooth to the distal adjacent direction.

4. The method for editing and controlling a tooth model as described in claim 2, characterized in that, When the determination is yes, the following also includes: Based on the spatial occlusion relationship between the adjacent teeth and the area to be edited, at least a portion of the adjacent teeth that occlude the area to be edited of the target tooth are determined.

5. The method for editing and controlling a tooth model as described in claim 1, characterized in that, Adjusting the display parameters of the area to be processed includes: Adjust the opacity of the area to be processed according to the change in the current viewing angle, so that the opacity of the area to be processed transitions continuously with the change in viewing angle.

6. The method for editing and controlling a tooth model as described in claim 5, characterized in that, The step of adjusting the opacity of the area to be processed based on the change in the current viewing angle includes: When the angle between the current viewing angle and the mesiodistal axis of the target tooth is less than or equal to the second threshold, the opacity of the area to be processed is adjusted to the minimum opacity. When the included angle is greater than the second threshold and less than the first threshold, the opacity of the area to be processed changes continuously and smoothly between the minimum opacity and opacity; Wherein, the first threshold is greater than the second threshold, and when the included angle reaches the first threshold, the area to be processed is canceled and restored to opaque.

7. The method for editing and controlling a tooth model as described in claim 1, characterized in that, The editing attributes include picking attributes, wherein adjusting the editing attributes of the area to be processed includes: When the opacity of the area to be processed is lower than the preset picking threshold or enters a transparent state, the area to be processed is excluded from the editing ray picking candidate set, or the area to be processed is marked as unpickable, so that the editing ray can penetrate the area to be processed and act on the area to be edited of the target tooth. When the opacity of the area to be processed reaches the preset picking threshold, the area to be processed is reinstated into the editing ray picking candidate set, or the unpickable mark of the area to be processed is removed.

8. The method for editing and controlling a tooth model as described in claim 1, characterized in that, After adjusting the display parameters and editing attributes of the area to be processed, the following is also included: The tooth model is rendered based on a preset drawing order and according to the current display parameters and editing attributes.

9. The method for editing and controlling a tooth model as described in claim 8, characterized in that, The area to be edited is the preparation edge line of the target tooth. Following the rendering of the tooth model based on the current display parameters and editing attributes, the process further includes: The edge lines are displayed in the tooth model using a first display style; Based on a preset two-dimensional cutting plane, the edge line is projected onto the two-dimensional cutting plane, and the projection of the edge line onto the two-dimensional cutting plane is displayed in a second display style that is different from the first display style.

10. The method for editing and controlling a tooth model as described in claim 1, characterized in that, The tooth segmentation information also includes tooth position numbers corresponding to each tooth region; wherein, determining the target tooth position according to the current editing operation command, and determining the target tooth and at least one adjacent tooth adjacent to the target tooth according to the tooth segmentation information, includes: The target tooth position is determined according to the current editing operation instruction, and the tooth region in the tooth segmentation information corresponding to the target tooth position is determined as the target tooth. Based on the tooth position numbering order and spatial adjacency relationship of each tooth region in the tooth segmentation information, at least one of the mesial adjacent tooth and distal adjacent tooth of the target tooth is determined as the adjacent tooth.

11. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the steps of the editing control method for the tooth model as described in any one of claims 1 to 10.

12. A method for displaying tooth edge lines without obstruction, comprising: Obtain a tooth model and identify the target tooth, the mesial adjacent teeth adjacent to the target tooth, and the distal adjacent teeth adjacent to the target tooth. Display the edge line of the target tooth, the edge line being represented by at least one edge control point and its fitted curve, the edge control point being used in response to user editing operations; The camera's current viewing angle is acquired in real time, and one of the mesial adjacent teeth and the distal adjacent teeth, located between the camera and the target tooth and facing the camera, is identified as the rendering tooth; The target tooth is rendered transparently or semi-transparently, while the target tooth and the other adjacent tooth among the mesial and distal adjacent teeth that are not identified as the target tooth are rendered opaquely, so that the outline and edge line of the target tooth are displayed without obstruction within the visible area of ​​the camera.

13. The method of claim 12, wherein, The determination of the rendering teeth includes: The directed line from the target tooth to the camera is used as the viewing line, and the mesiodistal axis of the target tooth is determined. The mesiodistal axis is a directed axis along the dental arch from the mesio-adjacent direction to the distal-adjacent direction, and its positive direction points to the side where the distal adjacent tooth is located. Calculate the first angle between the view line and the mesial-distal direction axis, and the second angle between the view line and the opposite direction of the mesial-distal direction axis; when the first angle is less than a preset angle threshold, the distal adjacent tooth is determined to be a rendering tooth; when the second angle is less than the preset angle threshold, the mesial adjacent tooth is determined to be a rendering tooth; when both are less than the preset angle threshold, the adjacent tooth corresponding to the smaller angle is determined to be the rendering tooth.

14. The method of claim 13, wherein, The transparent or semi-transparent rendering process includes: The opacity of the rendering tooth is determined by the angle between the view line and the direction axis corresponding to the rendering tooth; the smaller the angle, the lower the opacity of the rendering tooth. Wherein, when the rendered tooth is the distal neighbor tooth, the direction axis corresponding to the rendered tooth is the direction axis pointing from the target tooth to the distal neighbor tooth; when the rendered tooth is the mesial neighbor tooth, the direction axis corresponding to the rendered tooth is the direction axis pointing from the target tooth to the mesial neighbor tooth.

15. The method of claim 13, wherein, When neither the mesial adjacent tooth nor the distal adjacent tooth is located between the camera and the target tooth, it is determined that the camera's viewing angle has returned to the normal viewing direction; in response to the determination, the adjacent tooth that previously underwent the transparent or semi-transparent rendering process is automatically restored to opaque rendering, and the normal picking state of the adjacent tooth is restored.

16. The method of claim 12, wherein, Set drawing order parameters for the target tooth, the other adjacent tooth, the rendered tooth, and the edge line respectively, and prioritize the drawing order according to the size of the drawing order parameters, so that the comparison priority of the drawing order parameters is higher than the default sorting rule determined by the distance of the object to the camera; The opaque object, the rendered tooth, and the edge line are drawn sequentially from first to last. The opaque object includes the target tooth that maintains opaque rendering and the other adjacent tooth, so that the edge line is drawn after the rendered tooth, thereby covering the pixels already drawn by the rendered tooth on the screen pixels and appearing on the outermost layer.

17. The method of claim 16, wherein, Drawing the edge line includes: The depth value of each pixel of the edge line is compared with the depth value that has been written into the depth buffer by the opaque object, and pixels with depth values ​​greater than the corresponding depth values ​​in the depth buffer are discarded, so that the edge line is only visible on the surface of the target tooth facing the camera. The depth value of the edge line is not written to the depth buffer so that the depth buffer contains only the depth information of the geometry drawn in an opaque manner, for use by at least one of the semi-transparent blending of the rendering teeth, post-processing rendering dependent on the depth map, and picking based on the depth value to calculate the 3D coordinates.

18. The method of claim 12, wherein, While the rendering tooth is in the state of performing the transparent or semi-transparent rendering process, the rendering tooth is excluded from the candidate set of mouse ray picking, or the rendering tooth is set to be unpickable or pick-through, to ensure that the rendering tooth does not intercept the editing operation of the edge control point on the edge line of the target tooth.

19. The method of claim 18, wherein, The step of excluding the rendering teeth from the candidate set picked by the mouse ray includes: Obtain the opacity of the rendered tooth in the current frame; when the opacity is lower than a preset picking threshold, exclude the rendered tooth from the candidate set, or set it to be unpickable or pickable through; when the opacity is not lower than the preset picking threshold, reinstate the rendered tooth into the candidate set and restore it to a normal pickable state.

20. The method of claim 19, wherein, The rendering teeth are excluded from the candidate set in the same frame when they switch from an opaque state to the state of performing the transparent or semi-transparent rendering process, and the edge control points can be picked in the same frame when the rendering teeth begin to be transparent.

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