Specialized Terminology	Description
Cutting	It refers to the process of dividing a large point cloud dataset into multiple subsets, which typically represent different objects or different parts of objects within the point cloud.
Cutting direction	When performing segmentation of three-dimensional point cloud data, a directional segmentation strategy can be adopted, which involves selecting one or more predefined directions for segmentation. These directions can align with the standard coordinate axes (X, Y, Z axes) of the point cloud data, or they can be non-axial directions selected based on specific scene requirements.
Cutting interval	It refers to the distance selected for segmentation along a specific direction in three-dimensional point cloud data.
Point cloud contour fitting	It refers to fitting a set of scattered three-dimensional point clouds into contours with specific geometric shapes using mathematical models.
Point cloud multi-contour	Contours of multiple independent objects appear simultaneously in a single point cloud dataset. In a complex scene’s point cloud, there may be multiple different objects, each with its own contours and boundaries.
Point cloud multi-contour fitting	It refers to the process of analyzing and processing complex point cloud data to identify and fit the multiple contours of these objects.
Slice	Point cloud slicing refers to subsets obtained by cutting three-dimensional point cloud data along specific directions, which can be viewed as polygonal prisms.
Slice contour	Slice contour defines the bottom contour of the prism.
Slice integration	It refers to a technique used to calculate the volume of three-dimensional point clouds. For more details, refer to Zhi et al. [36].
Slice interval, Slice spacing	The slice interval defines the height of the prism.
Slice projection	It refers to the process of projecting a prism onto a two-dimensional plane.