Extract XYZ coordinates from point cloud data
xyz = readXYZ(
[x y z] coordinates from all points in the
pcloud, and returns them as
an n-by-3 matrix of n 3-D point coordinates.
If the point cloud does not contain the x, y,
and z fields, this function returns an error. Points that contain
NaN are preserved in the output. To preserve the structure of
the point cloud data, see Preserving Point Cloud Structure.
Load sample ROS messages including a ROS point cloud message,
Read the XYZ values from the point cloud.
xyz = readXYZ(ptcloud);
xyz— List of XYZ values from point cloud
List of XYZ values from point cloud, returned as a matrix. By default,
this is a n-by-3 matrix. If the point cloud object being
read has the
PreserveStructureOnRead property set to
true, the points are returned as an
h-by-w-by-3 matrix. For more
information, see Preserving Point Cloud Structure.
Point cloud data can be organized in either 1-D lists or in 2-D image styles. 2-D
image styles usually come from depth sensors or stereo cameras. The input
PointCloud2 object contains a
property that is either
Suppose you set the property to
pcloud.PreserveStructureOnRead = true;
Now calling any read functions (
readField) preserves the organizational structure of the point cloud.
When you preserve the structure, the output matrices are of size
m is the height, n is the width, and
d is the number of return values for each point. Otherwise, all
points are returned as a x-by-d list. This
structure can be preserved only if the point cloud is organized.
Not recommended starting in R2021a
You can now create messages as structures with fields matching the message object properties. Using structures typically improves performance of creating, updating, and using ROS messages, but message fields are no longer validated when set. Message types and corresponding field values from the structures are validated when sent across the network.
To support message structures as inputs, new functions that operate on specialized ROS messages have been provided. These new functions are based on the existing object functions of message objects, but support ROS and ROS 2 message structures as inputs instead of message objects.
The object functions will be removed in a future release.
|Message Types||Object Function Name||New Function Name|