Raytraced Iluminación Cinemática

First steps

Asset/Project Setup

Project settings -> Rendering -> RayTracing=True Level persistent (scene) and sublevels (try different lights). Create new level and drop it into Level panel (under the main level) Reference Imagery and cinematic Photorealism in CGI: from cinema (https://shotdeck.com/), global illumination, cinematic photorealism Types of Lights in UE in the context of RayTracing: Point, Spot, Rectangular (can add texture mask), Directional, Sky (enable CastRayTracingShadows and increase IntensityScale)

• ==Lighting motivations==: enviromental (natural, come from the world, primarily sun/moon light and sky ambience), emulated (placing light for enviromental and practical sources), practicals (real world light sources that can be seen in the frame) and cheated (all other light sources)

Quick starting with the Enviroment Light Mixer

All posible source for lighting in one panel (direcional light, sky light, sky atmosphere and volumetric clouds).

• ExponentialHeightFog: For use ExponentialHeightFog without print specific color turn InscatteringColor options to 'black'.

• SkyLight: Cast RayTraced shadows and increse Intensity (1-4). RecaptureScene when makes changes.

Setting your scene exposure / Real worl light levels

Add PostProcessVolume: For RayTracing Reflections (0.6-1). Play with values (same that camera) for Exposure Manual (13), CameraAperture (2.8), CameraShutterSpeed, CameraISO. Console commands: r.RayTracing.Reflections.Hybrid 1, r.RayTracing.Reflections, Reflections.ReflectionCaptures, r.RayTracinig.Reflections.RayTraceSkyLightContribution 1

Tips and tricks for cinematics photorealism

In PostProcessVolume: Enable GlobalIllumination (BruteForce or FinalGather) and AmbientOcclusion. For Reflection increase SamplesPerPixel=4-16 and Shadows=AreaShadows Bloom set SizeScale=0, Threshold=4 and Intensity=3 Enviromental light:

• Volumetric directional light: Enable VolumetricFog in ExponentialHeightFog, in DirectionalLight increase VolumetricScatteringInternsity=2000, add IndirectLightingIntensity and disable CastRayTracingShadows. Duplicate DirectLight an CastRayTracingShadown on this one and set intensity=0.05, VolumetricScatteringIntensity=20.

• SkyLight: Play with Intensity (0.5)

• ExponentialHeightFog: habilitala lo último

Emulated light:

• Rectangular light: Add a rect light in holes, increasing SamplesPerPixel=8. Disable SpecularScale=0

Daytimes

Day Interior - Overcast: HDRI backdrio for overcast or purely indirect light

Enviromental: Place actor -> HDRI Backdrop (place in another Level): Emissive static mesh

• HDRI backdrop: intensity=0.01

Emulated:

• Import PostProcessVolume and rectangle light from old levels. Gives sense of directionality comming from the windows (try to match backdrop image location).

• Rectangle light: twick volumetric scattering indirect light, indirect lighting intensity, atenuation radius.

Night interior -Emulating real world light sources

Add spots light in bulbs. Change light origin to an emmisive material. Make light movable and with some hot temperature. Modify source radius for softere shadows, indirectLightingIntensity and expand the OuterConeAngle and SourceRadius.

Enviromental:

• Spot light as a moon: Change temperature (cold) and volumetricScattering=20 (evaluate alone)

• ExponentialHeightFog: copy from another level

Cheated:

• RectLight: For a GlobalIlumination at night he uses a RectLight with a low Intensity (0.25) and adjusting the dimensinos and temperature.

Subject lighting

For iluminate specific actor use rect light with IndirectLightingIntensity=0 (avoid destroy scene lighting setup) Add pointLight on top of Camera (trick for cast delicate shadows over the metahuman face)

Virtual Grip Equipment & lighting channels

Add a negative plane with an absorbing material (black) for cutoff lightbounces. ==Add channel lighting in mesh details panel, set subject lighting for affect the channel set in mesh detail panel. (dont affect other objects)==