Why is it so difficult to create real world lighting?

My demands are rather simple, I think. I want my outdoor scenes lit by a skybox and interior scenes with skybox shining through windows and additional house lights.

In Unity there are so many lighting options. I am really having a hard time to make everylook look as it would be natural.

Also, I don't understand why I have to place reflection and light probes myself. Wouldn't / shouldn't Unity be smart enough to set it by itself? Maybe even better than I could do it myself?

Am I dumb and there is actually a reason why it is so difficult? Or is this bleeding edge, and Unity is still figuring things out and may come up with a smarter solution soon?

I don't know how many hours of tutorials I have already watched, and I still don't have a secure feeling about it.

Do others share my opinion that everything is over-complicated and that it should be fixed in the future, or do you all love the flexibility and complexity of the lighting?

 

Yes, it is difficult.
The placement of reflection and light probes can't easily be automated. It heavily depends on the context of your game. Where can all the moving objects go? It is not necessary to place light probes outside of that area? Where can the camera be at runtime? What can be seen? What is far away? Can some areas just be skipped? How dense should the placement of light probes and reflection probes be?
Designers usually know the answer to those questions. Unfortunately the answers will differ significantly depending on the context. Because of that, it is not an easy task.
But if you know exactly what you are looking for in your context, Unity allows you to programmatically place reflection and light probes. As such you could create an automation for your workflow.

Edit: Typos

 

@Dantus Can I ask an additional question, please? Do you think it is relatively easily possible to mix an outer scene with an interior scene? For example half of my scene is in a garden, and then the player walks into a house. Should these 2 be separated because it would be different to light both exterior and interior areas with the same lights, or can that easily be done in one and the same scene? I hope you understand what I mean. I am asking because each tutorial that I watch is either indoor or outdoor, but never both. Thank you.

 

The most useful tip I can give you is: Try it out!
I made some simple tests where it worked surprisingly well, but I have seen others that had problems and didn't get it to work. They used different settings compared to mine and struggled e.g. because of the baking which is still tricky in the current Unity 5 versions.
If you know what you want to achieve, just try it out to get a better understanding on your own. If you struggle, post screenshots to illustrate what doesn't work in your case. Maybe even post the complete project, such that others can check it directly and can give tips.

 

Remember to use HDR and tonemapping and set your lighting intensities to values somewhat resembling real life. Sunlight and skylight is usually much brighter than your interior lights so set higher intensities for the former.

And you don't really need to work with light probes and reflection probes to get real world lighting. You can add those later. First try and nail the color, intesity and feel of your actual lighting, then worry about lighting dynamic objects and reflections.

 

I've been working some, although not so much lately, on a "gameplay first" ( ) Arch Viz scene in Unity:
http://twiik.net/projects/apartment

I feel like the lighting is starting to look alright. The version I have locally looks a lot better, but it's extremely buggy so I would have to fix it up before I can upload it. I've been talking a bit with the people behind PAMELA about some realtime GI optimization lately so I'll probably work some more on my Arch Viz scene. In PAMELA they have great lighting and they're not doing anything particularly custom. You can do the same things yourself. They talk about it here:

There's also this extremely basic project I made which I still feel looks rather natural:
http://twiik.net/projects/unity-5-day-night-cycle-example-scene