In the "Coordinate File Conversions" window, coordinate transformations can be applied directly to the points within point cloud files.

Supported File Formats

The following file types are accepted as point clouds: CSV, E57, LAS, LAZ, PCD, PLY, PTS, TXT and XYZ.

For plain text files (CSV, TXT or XYZ), the program identifies a point cloud based on the following criteria:

• With Header: If the first line contains a header describing the columns, which must include at least the coordinates in formats such as: (x,y,z), (coord_x,coord_y,coord_z), (easting,northing,elevation), or (n,e,h).
• Without Header: If the file lacks a header, it is treated as a point cloud only if it contains at least three real values per line, interpreted as (x,y,z) coordinates.

Delimiters and Encoding

• Delimiter Identification: For all ASCII text files (CSV, TXT, XYZ and PTS), the delimiter is automatically identified by searching for the most frequently used character on a data line, in the following order of priority: comma (,), semicolon (;), Tab or space.
• PLY Files: While the PLY format supports both LittleEndian and BigEndian binary encodings, the system will always default to LittleEndian for new output, as it is the standard for Windows operating systems. BigEndian encoding is maintained only during direct file conversions.

3D Model Integrity (PLY)

For PLY files, additional information related to the 3D model (such as polygons, textures, etc.) is copied without altering the file structure. The transformation is applied exclusively to the vertex coordinates.

Attention: When converting a PLY file to any of the other formats, 3D model data, polygons, and textures will be omitted, as these formats do not support such information.

Conversion without coordinate modification

If you wish to convert the point cloud format without modifying the coordinates, you must create and use a transformation model containing a single coordinate operation of the 'calculation with custom formulas' type (see Coordinate operation – Own formulas Tab), using the settings X = x, Y = y, and Z = z, and for the inverse calculation x = X, y = Y, and z = Z, or you can download the Identity transform model, available online for [Worldwide], using the button located in the Universal Transformations section.

Attention: To maintain coordinate precision when converting to an ASCII text file, set the number of decimal places for writing accordingly.

Local to Global Coordinate Transformation

In the case of PCD files where the VIEWPOINT field is defined with a value other than the default (0 0 0 1 0 0 0), the points are stored in a local reference system and must be processed to reflect their real position. This header specification defines a translation and rotation which, transformed into a calculation matrix according to the PCL standard, is applied to all points to convert the coordinates into the global system, ensuring the correct alignment of the point cloud as per the technical documentation.

For E57 files with spherical coordinates, they are first converted to Cartesian coordinates in a local system. The conversion to the global system is performed by applying the pose transformation matrix (translation and rotation) included in the file. Per the ASTM E57 standard, this operation ensures the real-world positioning and correct alignment of the point cloud.

Note: For E57 files, data is saved in cartesian coordinates only; information regarding spherical coordinates will be omitted.

Calculation of Normals

If the file contains normal vectors (nx,ny,nz) for each point, these are recalculated to account for the applied transformation.

To determine the new 3D normal vector, the transformation is applied to the plane passing through the point perpendicular to the original vector, ensuring the normal remains correctly oriented after deformation.

Control of coordinate writing precision in text files (ASCII)

The number of decimal places used for export can be selected in the Options – Units Tab section. This setting is only valid if, in the Options – General Tab section, under the "Saving coordinates in file" box, the option "Fixing values at the decimal number of coordinates" is checked. Otherwise, coordinates will be written with the maximum number of decimals according to their specific type (planar, geocentric, or geographic).

Attention: Using a high number of decimal places will result in large files for text files containing point clouds.

Additional Attributes

In addition to coordinates and normals, the system captures other information associated with point clouds, such as: curvature, intensity, classification, confidence, color, near-infrared channel (NIR), GPS time, point scale, row index, column index, index returned by the sensor and total number of returns. Any other data present in the file is imported and treated as additional information.

Memory Management and Limits

Data reading is performed sequentially without loading the entire dataset into memory. The only exception is the compressed PCD format, where the data is loaded entirely into RAM. The limit for uncompressed data in PCD files is 4 GB.

Conversion Restrictions

• Not Supported: Conversions from "point cloud" format to text files containing "topographic points" (which include specific fields like Point Name, X, Y, Z coordinates, and Point Code).
• Supported: Conversion from "topographic points" to "point cloud" is supported for TXT, COO, CSV, GEO, XML or XYZ formats (refer to "Coordinate File Conversions - File extension in which coordinates are saved").