I/O & Management

I/O & Management holds the housekeeping tools: getting data in and out of LAS and LAZ, splitting a large file into manageable pieces, merging tiles back together, and repairing the acquisition metadata that is sometimes missing.

None of these tools analyse anything. They exist so that the analytical tools have something workable to run on, which in the browser matters more than usual: a survey that will not fit in memory has to be cut down first.

Start here

Lidar Tile

Splits a large point cloud into a regular grid of smaller files. The practical answer to a file too big to process in the page: tile it, then work tile by tile.

You set the tile dimensions and a minimum point count, below which a tile is not written at all, which avoids a scatter of nearly empty files at the edges.

Lidar Join

The opposite. Merges several files into one, preserving attributes and reconciling the headers. Use it to reassemble a study area that arrived as a dozen tiles, when the whole thing does fit.

Ascii To Las and Las To Ascii

The two conversions between point clouds and delimited text. Ascii To Las reads a CSV or a text file with columns for x, y, z and optionally intensity, class, return and time, and writes a proper LAS file with its EPSG code. Las To Ascii goes the other way, for inspection in a spreadsheet or for feeding a script.

Las To Shapefile converts the points into a vector point layer, which is how you get a cloud onto the map as ordinary features. Only sensible on a small or thinned cloud.

Lidar Colourize

Samples an orthophoto at each point’s position and stores the colour in the point record. This is what turns a grey point cloud into the photorealistic one people expect from a 3D viewer.

All the tools

Tool	What it does
Lidar Tile	Splits a cloud into a regular grid of tiles, with a minimum point count per tile.
Lidar Join	Merges several files into one, preserving attributes and headers.
Split Lidar	Splits points into separate files by class, source id, time window, spatial bin or point count.
Select Tiles By Polygon	Copies the tiles of a directory whose extent intersects a polygon layer.
Ascii To Las	Converts delimited text to LAS, with an EPSG code.
Las To Ascii	Exports every point attribute to delimited text.
Las To Shapefile	Converts the cloud into a vector point layer.
Lidar Colourize	Assigns each point a colour sampled from a georeferenced image.
Lidar Shift	Applies x, y and z offsets to every point, for datum or registration corrections.
Sort Lidar	Orders points by position and derived attributes, improving spatial coherence and compression.
Recover Flightline Info	Reconstructs flight line identifiers from gaps in the GPS time.
Lidar Tophat Transform	Extracts height above ground by a morphological white top hat, without a classified ground.

Notes

Files in, files out. These tools read and write LAS or LAZ, and the result is downloaded to your computer rather than added to the map. Reload it as an input when you chain another tool.

Coordinate systems. LAS files carry their own CRS. Lidar Shift moves coordinates, it does not reproject them: a datum shift is a translation, a projection change is not.