Dissecting Koola’s UE4 Archviz Magic

If you’re into Archviz stuff, it’s likely you did not get around seeing some of Koola’s recent work in Unreal Engine 4, pushing the boundaries of what’s possible in Realtime Architectural Visualization – some of it heavily inspired by Alex Roman’s outstanding The Third & The Seventh (rendered with V-Ray) from 2009.

 

After attracting quite some attention in his WIP thread, Koola prepared a little interior Demo Scene (inspired by the Chiyodanomori Dental Clinic by Hironaka Ogawa) for the Community to peek into his way of setting up a 3D Scene. The Environment was finally released yesterday on the Engine’s own Marketplace and is availiable for free – I highly recommend checking it out if you’re using UE4.

So I didn’t have too much time yet to take a look at every little detail, but a thing that immediately caught my eye was the way Koola used the Postprocessing Capabilites of UE4 to polish the overall look of the Scene – obviously, besides optimizing the static GI calculation, a good Postprocessing is key to achieving good results.

This is also one of the core strenghts of UE4, which allows in-depth realtime Postproduction work like Color Correction (LUT import), Bloom, CA Fringing, Vignette, Motion Blur, Depth of Field and more. Sidenote: As Mike Fricker, TD of Epic just announced in the weekly twitch Broadcast, OpenEXR support will be introduced with the upcoming Release of Unreal Engine 4.5 to offer VFX pipeline support for working in Nuke etc.

To give an impression of how much Post Effects are part of a good result, I made a little .GIF with a breakdown of Koola’s Demo Scene (Click to view full size):

I think it’s striking how big the impact of the last two Postproduction Steps are to the perceived quality. Koola states that he uses a custom LUT he made in Photoshop, which is the central element of his Post-Work on his scenes. A breakdown of the way LUTs work in UE4 and how to set them up in Photoshop can be found here.

Additionally, here’s the way he sets up indirect lighting with up to 7 manually placed bounce lights & cards:

Here are some of the changes he did for another of his Testcenes in the BaseLightmass.ini – also make sure to set the Light Build Quality inside the Editor to “Production” and set the Engine Scalability Settings to maximum Quality :

[DevOptions.StaticLightingProductionQuality]
NumShadowRaysScale=32
NumPenumbraShadowRaysScale=64
ApproximateHighResTexelsPerMaxTransitionDistanceScale=9
MinDistanceFieldUpsampleFactor=7
NumHemisphereSamplesScale=64
NumImportanceSearchPhotonsScale=6
NumDirectPhotonsScale=32
DirectPhotonSearchDistanceScale=.5
NumIndirectPhotonPathsScale=32
NumIndirectPhotonsScale=64
NumIndirectIrradiancePhotonsScale=32
RecordRadiusScaleScale=.45
InterpolationMaxAngleScale=.75
IrradianceCacheSmoothFactor=.75
NumAdaptiveRefinementLevels=3
AdaptiveBrightnessThresholdScale=.25
AdaptiveFirstBouncePhotonConeAngleScale=2.5


Takeaway

So the condensed takeway so far for me is:

• From a technical standpoint, the final perceived quality heavily depends on
  • Quality of Model/Architecture, Textures & Materials
  • Quality of Lighting / Global Illumination
  • Quality of Perspective (Chosen Viewing Angle) & Postprocessing

I’m looking forward into getting my head more into UE4, soon 🙂

//Update: Until then, here’s some more inspirational UE4 Work by other very talented people:

Benoît Dereau

Alden Filion, Former Level Artist at DICE, LA

Rafael Reis, Minas 3D, UE4arch.com

Alexis De Bosscher aka dbalex, BOCO Studio

//Update, January 2016: Here’s also a helpful article describing the technique to fake area lights with bouncecards like Koola does: https://www.unrealengine.com/blog/simulating-area-lights-in-ue4