Starting point for new engine feature?

Hey unreal devs,

I was hoping to get some ideas as either what docs/code to start reading through to get an idea (or maybe you can suggest a high level list of basic tasks) on how to go about implementing a new UI/Engine feature. I wish to support creating Voxel terrain(and possible worlds defined in voxel like structures entirely) through the editor. Kind of like a new editor mode to paint blocks into a scene, then have that stored in a custom made level format that gets used at runtime by the engine to not only render the world, but simulate it (gravity, etc). I’m not really looking for how to all of this, just namely the areas in the engine I would need to change and or look at to support this. I know I’ll be changing the editor and likely the engine itself, but I’m just looking for good references/places to start.

Thanks!