getPointsfromStruct.m

%{
 * Copyright (C) 2013-2025, The Regents of The University of Michigan.
 * All rights reserved.
 * This software was developed in the Biped Lab (https://www.biped.solutions/) 
 * under the direction of Jessy Grizzle, grizzle@umich.edu. This software may 
 * be available under alternative licensing terms; contact the address above.
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 * modification, are permitted provided that the following conditions are met:
 * 1. Redistributions of source code must retain the above copyright notice, this
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 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS AS IS AND
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 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
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 * AUTHOR: Bruce JK Huang (bjhuang[at]umich.edu)
 * WEBSITE: https://www.brucerobot.com/
 %}


function [points,XYZIR] = getPointsfromStruct(pointStruct)
    
    len = length(pointStruct.Fields);
    for i =1 : len
        pointField = rosmessage('sensor_msgs/PointField');
        pointField.Name = pointStruct.Fields(i).Name;
        pointField.Offset = pointStruct.Fields(i).Offset;
        pointField.Datatype = pointStruct.Fields(i).Datatype;
        pointField.Count = pointStruct.Fields(i).Count;
        pointFields(i) = pointField;
    end
    pointMsg = rosmessage('sensor_msgs/PointCloud2');
    pointMsg.Height = pointStruct.Height;
    pointMsg.Width = pointStruct.Width;
    pointMsg.PointStep = pointStruct.PointStep;
    pointMsg.RowStep = pointStruct.RowStep;
    pointMsg.Data = pointStruct.Data;
    pointMsg.Fields = pointFields;
    %payload points with xyz coordinates
    xyz = double(readXYZ(pointMsg));
    points = [xyz'; ones(1,size(xyz,1))];
    
    %xyzir points
    fieldnames = readAllFieldNames(pointMsg);
    if any(strcmp(fieldnames,'intensity')) 
    	intensity = double(readField(pointMsg,'intensity'));
    else
    	error("No intensity from Rosbag pointcloud2 messages");
    end
    
    if any(strcmp(fieldnames,'ring'))
    	ring = double(readField(pointMsg,'ring'));
    else
    	error("No intensity from Rosbag pointcloud2 messages");
    end
    XYZIR = [xyz'; intensity';ring'];
end