I spent the last week or so diving into unreal so I am still quite new to it. I love it but I realized it is indeed a game engine, and as obvious as that might sound, I also realized that may be important to try and learn the engine natural way of doing stuff, rather than taking our regular archviz workflow on other engines and trying to reproduce it on UE.
That said, I almost became crazy trying to understand the hdri lighting, which is **** easy to set up in whichever engine you are used to (me that´d be corona, vray at first).
Right to this moment what I got is this for hdri lighting on UE:
- Use a skylight and a .hdr on the “skylight specified cubemap”. Okay, that´s easy enought.
- Get a huge sphere and drop a material into it. This material will be set to unlit and you will use a “TextureSampleParameterCube” to insert your hdr texture there and a “reflection vector” with a “constant 3 vector” attached so it won´t give you an error. I have no idea as to why do I need those last slots but well, for the moment it´s working, so that´s fine. I would like to understand that though.
I think that is physically correct and works just fine, but it´s not really enought. The background obtained this way is kind of wash out and should look more like what this tut shows https://80.lv/articles/understanding-lighting-creation-in-games/, but I found impossible to get that result without my sun getting black artifacts and odd things. Then it´s always the problem with the shadows when using hdri. It pretty much depends on your maps but I could not get any aceptable shadow out of Peter Guthrie´s maps and I think everyone is using a sunlight attached to their background.
So summarizing, the part of hdri lighting regarding lighting itself I found it really easy to set up within UE via a skylight specified cubemap.
Then the part regarding background and shadows, that´s another story. I found tutorials (some really confusing ones) and several methods, more like workarounds for something UE is not that much into. That was my impression. Is this as I stated? Do you guys feel that way too or it´s just me?
All that leads me to procedural skies for our scenes, because it is the way UE seems to want us to create atmosphere with. The main question here is for me, could we forget about hdri lighting if we master the integrated tools for procedural skies? I think I would love to.
Setting up the mood of your scene with your sky and using a skylight to catch the light and reflection would be as physically correct and hi quality as using hdri lighting?
Could this two mix (using hdri on skylight, sunlight for shadows, and procedural skies as background only)?
I found a plugin TrueSky that looks fantastic, and I don´t think I need better backgrounds than those of the reel.
What are your thoughts on this matter?
I also thought it could be nice and useful if we all wrote here our workflows as a list like I did atop this, so feel free to do so
Hope this topic is of some interest.