pcwrite

Write 3-D point cloud to PLY or PCD file

Syntax

pcwrite(ptCloud,filename)

pcwrite(ptCloud,filename,Encoding=encodingType)

Description

pcwrite(ptCloud,filename) writes the point cloud object, ptCloud, to the PLY or PCD file specified by the input filename.

pcwrite(ptCloud,filename,Encoding=encodingType) writes a pointCloud object, ptCloud, to a PLY file that is in the specified format.

Examples

Write 3-D Point Cloud to PLY File

Load a point cloud into the workspace.

ptCloud = pcread("teapot.ply");
pcshow(ptCloud); 

pcwrite(ptCloud,"teapotOut",Encoding="binary");

Write 3-D Organized Point Cloud to PCD File

Load a MAT file containing point cloud data into the workspace.

load("object3d.mat");
pcwrite(ptCloud,"object3d.pcd",Encoding="ascii");
pc = pcread("object3d.pcd");
pcshow(pc);

Input Arguments

filename — File name

character vector | string scalar

File name, specified as a character vector or string scalar. The input file type must be a PLY or PCD format file.

For a PLY-file, the pcwrite function converts an organized M-by-N-by-3 point cloud to an unorganized M-by-3 format. It converts the format because PLY files do not support organized point clouds. To preserve the organized format, you can save the point cloud as a PCD-file.

If you do not specify the file name with an extension, the function writes the file in a PLY-format. All NaN or Inf values will be skipped when writing to a PLY file.

ptCloud — Object for storing point cloud

pointCloud object

Object for storing point cloud, specified as a pointCloud object.

encodingType — Encoding type for output file

"ascii" | "binary" | "compressed"

Encoding type for the output file, specified as "ascii", "binary", or "compressed". This table summarizes the valid and default encoding types for PLY and PCD file formats.

File Format	Valid Encodings
PLY	"ascii" "binary" (default)
PCD	"ascii" "binary" "compressed" (default)

To improve performance when writing large point clouds, use the "compressed" or "binary" encoding type.

Version History

Introduced in R2015a

R2026a: Write point clouds with additional Color property data types

You can now write a pointCloud object with a Color property of data type uint8, uint16, single, or double to a PLY or PCD file. In previous releases, the valid data types for the Color property depends on the file format you write to.

Valid Color Data Types

File Format	R2025b	R2026a
PLY	uint8, uint16	uint8, uint16, single, double
PCD	uint8	uint8, uint16, single, double

R2026a: Change in default encoding type

The default value of the encodingType argument is now "binary" for PLY files and "compressed" for PCD files. Before R2026a, the default value is "ascii" for both file formats.

In most cases, you do not need to make any changes to your code. However, if you specifically want to write point cloud data to a PLY or PCD file with ASCII encoding, you must specify the encodingType argument as "ascii", as shown in this command: pcwrite(ptCloud,"sample.ply",Encoding="ascii").

R2026a: Improved performance

When you use the pcwrite function with the default encoding type, the function shows improved performance. When you use the pcread function to read a file generated by the pcwrite function, the pcread function also shows improved performance. The performance improvement increases as the number of points stored in the point cloud increases. For example, writing and then reading a point cloud using this code is about 17x and 11x faster, respectively, than in the previous release.

function [tWrite,tRead] = timingTest
    % Create a large point cloud
    rng("default");
    N = 1e6; % Number of points

    x = -50 + 100*rand(N,1);        % range [-50, 50]
    y = -50 + 100*rand(N,1);        % range [-50, 50]
    z = 10*rand(N,1);               % range [0, 10]

    ptCloud = pointCloud([x y z]);

    % Measure execution time of the operations
    tWrite = timeit(@()pcwrite(ptCloud,"temp.ply"));
    tRead = timeit(@()pcread("temp.ply"));
end

This table shows the approximate execution times required to write and read point cloud data to and from a PLY file.

Release	pcwrite Execution Time	pcread Execution Time
R2025b	2.19 s	0.56 s
R2026a	0.13 s	0.05 s

The code was timed on a Debian^® 12, Intel^® Xeon^® CPU W-2133 @ 3.60 GHz test system by calling the function timingTest.