Digital orthodontics represents a prominent and critical application of computer vision technology in the medical field. So far, the labor-intensive process of collecting clinical data, particularly in acquiring paired 3D orthodontic teeth models, constitutes a crucial bottleneck for developing tooth arrangement neural networks. Although numerous general 3D shape generation methods have been proposed, most of them focus on single-object generation and are insufficient for generating anatomically structured teeth models, each comprising 24-32 segmented teeth. In this paper, we propose TeethGenerator, a novel two-stage framework designed to synthesize paired 3D teeth models pre- and post-orthodontic, aiming to facilitate the training of downstream tooth arrangement networks. Specifically, our approach consists of two key modules: (1) a teeth shape generation module that leverages a diffusion model to learn the distribution of morphological characteristics of teeth, enabling the generation of diverse post-orthodontic teeth models; and (2) a teeth style generation module that synthesizes corresponding pre-orthodontic teeth models by incorporating desired styles as conditional inputs. Extensive qualitative and quantitative experiments demonstrate that our synthetic dataset aligns closely with the distribution of real orthodontic data, and promotes tooth alignment performance significantly when combined with real data for training. The code and dataset are available at https://github.com/lcshhh/teeth_generator.

Abstract Thin‐film interference is a significant optical phenomenon. In this study, we employed the transfer matrix method to pre‐calculate the reflectance of thin‐films at visible light wavelengths. The reflectance is saved as a texture through color space transformation. This advancement has made real‐time rendering of thin‐film interference feasible. Furthermore, we proposed the implementation of shallow water equations to simulate the morphological evolution of liquid thin‐films. This approach facilitates the interpretation and prediction of behaviors and thickness variations in liquid thin‐films. We also introduced a viscosity term into the shallow water equations to more accurately simulate the behavior of thin‐films, thus facilitating the creation of authentic interference patterns.

Existing learning-based algorithms have a certain potential in visual odometry. In this work, we propose the solution of the learning-based method, which contains the attention mechanism and pose graph optimization. We set a self-supervised network as our backbone to cope with image data and error-heavy estimation pose for pose correction. The pre-processing camera poses involved in the network can provide prior information. Combining the advantages of the abundant feature information and efficient attention mechanism, we design a geometric attention module that is sensitive to geometrical structure from images to accurately regress the rotation matrix. Then we improve the loss function with the weights of the attention module to consider the diversity of the data. Experimental results demonstrate the effectiveness and reliability of our approach on the public datasets KITTI with monocular task and stereo task. In comparison, the proposed method is superior to the existing methods in the translation component. In the self-supervised network, learning an attention mechanism can extract an effective connect relation of feature maps. We conduct ablation experiments under the self-supervised network backbone setting different strategies, and conclude that the proposed attention module is applicable to various sequences, and provide loss function improvements on the visual odometry task.