Is there a filmic equivalent to this in UE4?
UE4 already handles light in a physically based way, so it doesn’t need the tweaks mentioned in that video (although Eye Adaptation isn’t really a replacement for physically based camera). The way UE4 handles light is what allowed them to add HDR display support pretty quickly and easily without overhauling the lighting and rendering in the engine.
If you want to get great lighting on a specific scene, I’d suggest starting with setting Eye Adapation to a fixed exposure instead. Using a value between 6 and 12 for the sun as a directional light and 1/4 of that value for the skylight is a good starting point and close enough to realistic. Plug those values in and then adjust the exposure to compensate.
The new tonemapper in 4.15 should help add the de-saturation discussed at 22:00.
I’ve done as suggested many times. But I still find the results unpleasing. I have rooms much like the example in the video being lit primarily by sunlight coming thru windows and the room lighting has too much contrast. The rooms are a mix of harsh light and harsh shadows. I keep finding myself wanting to add fill lighting, turning on GI ambient lighting, or cranking up the diffuse boost. I guess what I’m looking for is a method to reduce the lighting contrast to get a better f-stop dynamic range.
Making sure you have plenty of GI bounces will be important - the default is 3 I think whereas I’ve (in my VFX past) needed 30 to extinguish enough of the energy into the room. This ‘lowers the contrast’ by having that light evenly diffused around and not clamped off from the bounce limit.
Playing with the Tonemapper from then - things like Gamma etc will bring the mids up and flatten it out. I’m still yet to get under the hood of the 4.15 tonemapper but it should be capable of mapping that tonal range into your display (like the video shows)
Matt Hermans
VisualizeHDR will actually show you the range. Looks like it’s 12 stops by default, from -8 to 4. You can easily change the values in post processing settings under Histogram Log Min and Max. Playing with those settings isn’t going to do much by itself, I can get pretty similar results to that video by just playing with the other exposure and color grading settings.
We definitely need someone more experienced with cameras/lighting/rendering to give advice on if increasing the range is actually going to do much, and what is physically accurate. I assume UE4 (light mass, lights, post processing, etc) is tuned by default to work well with the default HDR range UE4 uses. What a camera, UE4, your eyes, and your monitor does is take real life and crushing it down to a smaller range that eventually your (probably sRGB) display will show. There’s so many steps that happens along the way, but UE4 doesn’t use the sRGB for rendering which is the issue with Blender by default.
What the post processing, color grading, exposure, etc settings are doing is essentially playing with how you are mapping a HDR range to the sRGB color range.