PTX

PTX is a structured, text-based file format used for storing and exchanging point cloud data collected via terrestrial laser scanning. It is particularly suitable for handling complex datasets that involve multiple scan stations or viewpoints within a single file.

Unlike simpler formats such as PTS, PTX files store not only the spatial coordinates (X, Y, Z) and reflectance values of each point, but also comprehensive scanner metadata including scan position, orientation, and sensor settings. This makes the PTX format ideal for detailed documentation, registration, and alignment of scans from various positions within a larger environment.

A PTX file begins with a header section that defines the number of scan positions and their respective transformation matrices. The following sections list the points associated with each scanner position, enabling structured processing and accurate spatial reconstruction.

Due to its verbose structure and plain-text encoding, PTX files tend to be large in size. Therefore, they are often converted to binary or compressed formats like LAS or LAZ to optimise storage, sharing, and rendering performance in 3D software environments.

PTX is commonly used in:

• Industrial site modelling for digital twin applications
• Building and infrastructure documentation
• Heritage site scanning and cultural preservation
• Construction verification and progress monitoring

See also: Point Cloud, Point Cloud Formats, PTS