Console Variables

Vite-specific console variables and the stock ones you most often need, grouped by subsystem. This is a curated list, not an exhaustive dump — use help or the console's autocomplete for the full set.

Several ray tracing variables in this list are compiled out in a default build. They will set successfully and render nothing. Availability is noted per variable; see Compile-Time Switches.

Set variables at runtime in the console, or persistently in Config\DefaultEngine.ini:

[/Script/Engine.RendererSettings]
r.Vite.SMAA.Mode=1
r.HBAO.Enable=1

Vite-specific

These do not exist in stock UE 4.27.

Variable	Default	Purpose
`r.Vite.SMAA.Mode`	1	SMAA quality. 0 = Low, 1 = High. See Anti-Aliasing.
`r.Vite.SSAO`	—	Vite's optimised SSAO path. See Ambient Occlusion.
`r.AntiAliasing.SMAA.Debug`	—	SMAA debug visualisation
`p.VitePhysXFixedTimestep.Enabled`	0	Enable fixed timestep physics
`p.VitePhysXFixedTimestep.DeltaTime`	1/60	Fixed step duration in seconds
`p.VitePhysXFixedTimestep.MaxTimesteps`	—	Maximum steps per frame
`p.VitePhysXFixedTimestep.MaxCumulativeExtraSteps`	—	Cap on accumulated catch-up steps
`p.VitePhysXFixedTimestep.LimitType`	—	How overload is handled
`p.VitePhysXFixedTimestep.InterpolationMode`	—	Render interpolation between fixed steps

The p.VitePhysXFixedTimestep.* variables require a build with VITE_PHYSX_FIXED_TIMESTEP=1. See Fixed Timestep.

Ray tracing

Variable	Default	Availability	Page
`r.RayTracing.Reflections`	0	Available	RT Reflections
`r.RayTracing.Shadows`	0	Available	RT Shadows and AO
`r.RayTracing.AmbientOcclusion`	0	Available	Ambient Occlusion
`r.RayTracing.SkyLight`	—	Available	Ray Tracing
`r.RayTracing.GlobalIllumination`	-1	Compiled out	Global Illumination
`r.RayTracing.Translucency`	0	Compiled out	RT Translucency and Caustics
`r.RayTracing.SampledDirectLighting`	0	Compiled out	RTXDI

A value of -1 means the setting is driven by the post-process volume rather than the console variable.

Culling and scene setup

Variable	Purpose
`r.RayTracing.Culling`	Ray tracing instance culling mode
`r.RayTracing.Culling.Radius`	Culling distance
`r.RayTracing.Culling.Angle`	Angular culling threshold
`r.RayTracing.SceneCaptures`	Whether scene captures build ray tracing scenes
`r.RayTracing.PreGather`	Pre-gather pass control

Culling settings are among the most effective ray tracing performance levers, and Vite changes some of their defaults — see Engine Defaults.

Sky light

Variable	Purpose
`r.RayTracing.SkyLight.SamplesPerPixel`	Sample count
`r.RayTracing.SkyLight.MaxRayDistance`	Ray length limit
`r.RayTracing.SkyLight.ScreenPercentage`	Resolution scale for the sky light pass
`r.RayTracing.SkyLight.Denoiser`	Denoiser selection
`r.RayTracing.SkyLight.EnableMaterials`	Evaluate materials on hit
`r.RayTracing.SkyLight.EnableTwoSidedGeometry`	Two-sided geometry handling

ScreenPercentage and SamplesPerPixel are the two to reach for when the sky light pass is too expensive.

Translucency

Compiled out by default.

Variable	Purpose
`r.RayTracing.Translucency.HalfRes`	Half-resolution translucency
`r.RayTracing.Translucency.HybridDepthThreshold`	Hybrid translucency depth threshold
`r.RayTracing.Translucency.HybridDepthBias`	Hybrid translucency depth bias
`r.RayTracing.PrimaryRays.IncludeDOF`	Include depth of field in primary rays

RTXDI (sampled lighting)

Compiled out by default. r.RayTracing.SampledDirectLighting is the master switch; the r.RayTracing.SampledLighting.* family — over sixty variables covering reservoir counts, spatial and temporal resampling, ReGIR cell configuration and per-light-type toggles — tunes it.

The ones worth knowing first:

Variable	Default	Purpose
`r.RayTracing.SampledLighting.Mode`	1	Sampling mode
`r.RayTracing.SampledLighting.InitialSamples`	8	Initial candidate samples
`r.RayTracing.SampledLighting.Spatial`	1	Spatial resampling
`r.RayTracing.SampledLighting.Temporal`	1	Temporal resampling
`r.RayTracing.SampledLighting.NumReservoirs`	-1	Reservoir count, -1 for automatic
`r.RayTracing.SampledLighting.Denoiser`	—	Denoiser selection
`r.RayTracing.SampledLighting.DebugMode`	—	Debug visualisation

See RTXDI.

Caustics

Mesh and water caustics are driven primarily by post-process volume settings rather than console variables, and both are compiled out by default. Related variables:

Variable	Purpose
`r.RayTracing.BuildRayTracingMeshForCaustics`	Build caustics-capable ray tracing geometry
`r.ParallelCausticsMap`	Parallel caustics map rendering
`r.PathTracing.ApproximateCaustics`	Approximate caustics in the path tracer

See RT Translucency and Caustics.

Global illumination

Variable	Purpose
`r.RTXGI.DDGI`	Master DDGI toggle
`r.RTXGI.DDGI.LightingPass.Scale`	Lighting pass resolution scale
`r.RTXGI.DDGI.LightingPass.RelativeDistanceThreshold`	Distance rejection threshold
`r.RTXGI.DDGI.LightingPass.NormalPower`	Normal weighting
`r.RTXGI.DDGI.ProbesTextureVis`	Probe texture visualisation
`r.RTXGI.DDGI.ProbesTextureVis.IrradianceScalar`	Visualisation scaling
`r.RTXGI.DDGI.StatVolume`	Per-volume statistics
`r.RTXGI.MemoryUsed`	Report DDGI memory usage

The RTXGI plugin is enabled by default. See Dynamic DDGI and Global Illumination.

Ambient occlusion

Variable	Default	Purpose
`r.HBAO.Enable`	0	Enable HBAO+. Multiplies over the screen-space AO buffer.
`r.HBAO.HighPrecisionDepth`	0	0 = FP16 internal depth, 1 = FP32. Use FP32 to avoid self-occlusion banding on distant objects.
`r.HBAO.GBufferNormals`	1	0 = reconstruct normals from depth, 1 = fetch GBuffer normals

HBAO+ has additional per-volume settings in the post-process volume: power exponent (default 2.0), radius (2.0), bias (0.1), small-scale AO (1.0), blur radius (2 pixels), blur sharpness (16.0), max view depth (9500), depth sharpness (50.0), and foreground and background AO distances.

The r.HBAO.Enable help text describes HBAO+ as DX11-only. This is out of date; there is a working D3D12 implementation. See Ambient Occlusion.

Tessellation

Variable	Default	Purpose
`r.TessellationAdaptivePixelsPerTriangle`	48.0	Global tessellation factor multiplier. Lower means more triangles.

See Tessellation.

Hair

Variable	Purpose
`r.TressFX.StrandsMode`	Debug render mode. 0 = off, 1 = simulation strands, 2 = render strands with simulation influence, 3 = hair UV, 4 = root UV, 5 = seed, 6 = dimensions
`r.TressFX.Interoplation.FrustumCulling`	Frustum culling for interpolation. Default 1.
`r.TressFX.MorphTargetMeshVisualization`	Morph target mesh visualisation

See Hair Rendering.

Volumetric fog

Variable	Purpose
`r.RayTracing.VolumeFogMode`	Ray traced volumetric fog mode
`r.VolumetricFog.UseUpScaledSizeVolumetricFog`	Render volumetric fog at output rather than internal resolution

r.VolumetricFog.UseUpScaledSizeVolumetricFog only exists in builds with VITE_DLSS_PATCH=1. It exists to fix volumetric fog resolution when upscaling. See Upscalers.

Profiling

Standard Unreal, but worth having in one place:

Command	Shows
`stat unit`	Frame, Game, Draw, GPU and RHIT timings. Start here.
`stat unitgraph`	The same over time
`stat game`	Game thread breakdown
`stat scenerendering`	Render thread breakdown
`stat gpu`	GPU pass breakdown
`stat physics`	Physics solver time
`stat rhi`	RHI resource statistics
`stat memory`	Memory usage
`profilegpu`	Single-frame GPU capture
`recompileshaders changed`	Recompile modified shaders
`recompileshaders global`	Recompile global shaders

See Profiling.

Finding variables yourself

Command	Effect
`help`	Dumps all console variables and commands to the log
`<partial name>` then Tab	Autocomplete in the console
`<variable>` with no value	Prints the current value and help text
`DumpConsoleCommands`	Lists commands

Help text in the engine is occasionally stale — HBAO+'s DX11-only claim is one example. When behaviour and help text disagree, the source is authoritative.