lab4.md

@@ -324,10 +324,12 @@ int main(int argc, char** argv)
 }
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-In RViz you can select to display a marker array, and you should see two cubes. You should then modify the program to query the database and show the humans and tables. Once you have completed the lab you should see something similar to this (the exact numbers of cubes and their positions may be different for you):
+In RViz you can select to display a marker array, and you should see two cubes. You should then modify the program to query the database and show the humans and tables. Once you have completed the lab you should see something similar to this:
 
 ![rviz_marker_array](uploads/252cff8dffe1c7abad224ce6a02703b4/rviz_marker_array.png)
 
+**Note:** the previous images show all the possible objects in the database, after you have completed the exploration you will only see a limited number of objects.
+
 ## TST
 
 The final step is to write a simple program that query the database for all the humans (all the objects of class `human`), generate a TST (as a json file) for driving to all the location of the humans (as a sequence of `drive_to`) and execute that TST. For simplicity, you can make your program output the TST to a file and then execute the TST with the service call of lab 3.