3D meshes are one of the main components of Virtual Reality applications. However, many network and computational resources are required to process 3D meshes in real-time. A potential solution to this challenge is to dynamically adapt the Level of Detail (LoD) of a 3D mesh based on the object's position and the user's viewpoint. In this paper, we conduct a subjective study to investigate users' quality perception of 3D meshes with dynamic Level of Detail in a Virtual Reality environment. The subjective experiment is carried out with five 3D meshes of different characteristics, four Levels of Detail, and four distance settings. The results of the experiment show that the impact of the dynamic level of detail depends on both the position of the 3D object in the virtual world and the number of vertices of the original mesh. In addition, we present a quality model that can accurately predict the MOS score of a LoD version of a 3D mesh from the number of vertices and the distance from the viewpoint.

翻译：三维网格是虚拟现实应用的核心组成部分之一。然而，实时处理三维网格需要大量的网络与计算资源。针对这一挑战的潜在解决方案是根据物体位置与用户视点动态调整三维网格的细节层次。本文通过主观实验研究用户在虚拟现实环境中对具有动态细节层次的三维网格的质量感知。该主观实验采用五个不同特征的三维网格、四种细节层次以及四种距离设置进行。实验结果表明，动态细节层次的影响既取决于三维物体在虚拟世界中的位置，也取决于原始网格的顶点数量。此外，我们提出了一个质量模型，该模型能够根据顶点数量和视点距离准确预测三维网格特定细节层次版本的平均意见得分。