How to construct 3D road/environment cloud point map from .bag file?
Hello all,
I have several .bag files, but I have no experience in ROS nor I have any experience in .bag file. I want to see if it is possible to construct the 3D road/environment cloud points from these .bag files. So far I only export some X, Y and Z data from .bag files using Matlab (into .txt file), and I loaded the .txt file into a software called CloudCompare to see what are the data looks like. In Matlab I saw these information:
1/bosch_scan 2/cloud 3 /gps 4 /odom 5 /tf 6 /tf_static
In CloudCompare, the points look like this:
I don't know what does this cloud is. It looks like some Lidar data, surrounding a car. The data's coordinate seems to be based on the car's local coordinate, that is why all these data are gathered together.
May I ask, how can I convert the X, Y and Z coordinates of the above data, so that when I load the converted X, Y and Z data into CloudCompare, the road and environment can be shown? That is to say, to 'expand' the points around the car in time, so that the new points are located at the global coordinates rather than at the car's local coordiante?
Thank you all.