Holodeck – A High Fidelity Simulator for Reinforcement Learning

Synthetic training data. Sometimes it's cheaper / safer / easier to work with simulated data rather than real world sensor data. For some types of machine learning, a simulation is "real enough".

Someone asked me to build a startup doing the same. His most convincing use case was training camera systems to detect people falling overboard on cruise ships, etc. It's impractical / dangerous to use real world camera data for that.

There are other advantages, e.g., being able to generate simulations where everything is already labeled.

There are a few papers which shows that this works quite well.

I was going to argue the opposite that such high fidelity images are not really necessary to learn basic behaviour, in fact they look like overkill to me

As it says in the first sentence, this simulator is built on top of Unreal Engine 4.