You can use either Unity or Unreal Engine - both are free to develop. They cut into your returns, though. Some people are talking about app building. Unity and

You can use either Unity or Unreal Engine - both are free to develop. They cut into your returns, though. Some people are talking about app building. Unity and Unreal 4 are both game engines which means they run simulations. Since they use C# and C++ among other languages, and the target is desktop PC, you can run any software. They both also have other ways to write logic with triggers or blueprints, etc.