Zhu Xiaoqiang, Liu Xiaomei, Liu Sihu, Shen Yalan, You Lihua, Wang Yimin
School of Communication and Information Engineering, Shanghai University, Shanghai, China.
Guangdong Institute of Intelligence Science and Technology, Hengqin, China.
Front Neuroinform. 2022 Oct 27;16:953930. doi: 10.3389/fninf.2022.953930. eCollection 2022.
Creating high-quality polygonal meshes which represent the membrane surface of neurons for both visualization and numerical simulation purposes is an important yet nontrivial task, due to their irregular and complicated structures. In this paper, we develop a novel approach of constructing a watertight 3D mesh from the abstract point-and-diameter representation of the given neuronal morphology. The membrane shape of the neuron is reconstructed by progressively deforming an initial sphere with the guidance of the neuronal skeleton, which can be regarded as a digital sculpting process. To efficiently deform the surface, a local mapping is adopted to simulate the animation skinning. As a result, only the vertices within the region of influence (ROI) of the current skeletal position need to be updated. The ROI is determined based on the finite-support convolution kernel, which is convolved along the line skeleton of the neuron to generate a potential field that further smooths the overall surface at both unidirectional and bifurcating regions. Meanwhile, the mesh quality during the entire evolution is always guaranteed by a set of quasi-uniform rules, which split excessively long edges, collapse undersized ones, and adjust vertices within the tangent plane to produce regular triangles. Additionally, the local vertices density on the result mesh is decided by the radius and curvature of neurites to achieve adaptiveness.
由于神经元具有不规则且复杂的结构,创建高质量的多边形网格以表示其膜表面用于可视化和数值模拟目的是一项重要但并非易事的任务。在本文中,我们开发了一种新颖的方法,可从给定神经元形态的抽象点和直径表示构建一个封闭的三维网格。神经元的膜形状是通过在神经元骨架的引导下逐步使初始球体变形来重建的,这可以看作是一个数字雕刻过程。为了有效地使表面变形,采用局部映射来模拟动画蒙皮。结果,仅需要更新当前骨骼位置的影响区域(ROI)内的顶点。ROI是基于有限支持卷积核确定的,该卷积核沿神经元的线骨架进行卷积以生成一个势场,该势场在单向和分叉区域进一步平滑整个表面。同时,在整个演化过程中的网格质量始终由一组准均匀规则保证,这些规则会分割过长的边、收缩过小的边,并在切平面内调整顶点以生成规则的三角形。此外,结果网格上的局部顶点密度由神经突的半径和曲率决定,以实现适应性。