Goals

To enable organisms to move around in an Empirical world to accomplish a swarming task.

Setup

  • Remember to start WSL if you are on Windows
  • Pull down the new MovingOrgs-Lab starter code repository from the 361-F26 GitHub Organization with git clone --recurse-submodules [URL] or git submodule update --init --recursive if you cloned without the recurse submodules command.
  • Set up Emscripten as normal: 
      cd emsdk
  ./emsdk install 3.1.49
  ./emsdk activate 3.1.49
  source ./emsdk_env.sh
  cd ..

Running web GUI

Start the web GUI starter code running with ./compile-run-web.sh and you should see a grid of yellow circles with a little black square hiding somewhere.

Exercise 1

You’ll start by making your organism move around the world. Empirical doesn’t actually support moving organisms very well, so I provided a MoveOrganism method already in World.h. Empirical does provide a very useful GetRandomNeighborPos(i) that will return a neighboring world position based on the structure already set for the world.

Your task: Use those two methods to have your organism run around the world randomly by editing the Update method in World.h. Make sure to compile and run to see the little critter go!

Exercise 2

As you read, a basic algorithm that allows a single ant to build a heap of sand particles is the following:

  • If it finds a grain and it’s not already holding one, pick up the grain and move randomly
  • If it finds a grain and it is already holding another one, drop the grain and move randomly
  • Otherwise, move randomly

Implement this algorithm in Org.h. You can access the world’s methods through the world variable. Make whatever changes are needed in World.h as well. Remember to compile and run the web version to see the ant forming a heap!

Exercise 3

Part of the point of this algorithm is that it works with just one ant or multiple. Edit MoveOrganism in World.h to have ants avoid colliding with each other and web.cpp to introduce more ants. Make sure your small colony is now even better at building a heap!

Submission

You aren’t required to submit labs in this class, but you can for an extra engagement credit. Complete through exercise 3 and then push it to GitHub:

git add World.h web.cpp Org.h
git commit -m "finished basic heap-building"
git push

Extensions

If you have extra time, there are a lot of expansions to the system that you could try:

  • Add in a config panel and data collection to the native mode to quantitatively see how well the ant it doing. What data do you need to output?
  • Have the ants use up energy points and need to rest or eat
  • Have the ants respond to each other by more than just not colliding, perhaps following?
  • Introduce another type of ant (via another class) that follows a different algorithm to see how much it messes things up