Console Variables
Set variables at runtime in the console, or persistently in Config\DefaultEngine.ini:
Vite-specific
These do not exist in stock UE 4.27.
Variable | Default | Purpose |
|---|---|---|
| 1 | SMAA quality. 0 = Low, 1 = High. See Anti-Aliasing. |
| — | Vite's optimised SSAO path. See Ambient Occlusion. |
| — | SMAA debug visualisation |
| 0 | Enable fixed timestep physics |
| 1/60 | Fixed step duration in seconds |
| — | Maximum steps per frame |
| — | Cap on accumulated catch-up steps |
| — | How overload is handled |
| — | Render interpolation between fixed steps |
Ray tracing
Variable | Default | Availability | Page |
|---|---|---|---|
| 0 | Available | |
| 0 | Available | |
| 0 | Available | |
| — | Available | |
| -1 | Compiled out | |
| 0 | Compiled out | |
| 0 | Compiled out |
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 |
|---|---|
| Ray tracing instance culling mode |
| Culling distance |
| Angular culling threshold |
| Whether scene captures build ray tracing scenes |
| 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 |
|---|---|
| Sample count |
| Ray length limit |
| Resolution scale for the sky light pass |
| Denoiser selection |
| Evaluate materials on hit |
| 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 |
|---|---|
| Half-resolution translucency |
| Hybrid translucency depth threshold |
| Hybrid translucency depth bias |
| 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 |
|---|---|---|
| 1 | Sampling mode |
| 8 | Initial candidate samples |
| 1 | Spatial resampling |
| 1 | Temporal resampling |
| -1 | Reservoir count, -1 for automatic |
| — | Denoiser selection |
| — | 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 |
|---|---|
| Build caustics-capable ray tracing geometry |
| Parallel caustics map rendering |
| Approximate caustics in the path tracer |
Global illumination
Variable | Purpose |
|---|---|
| Master DDGI toggle |
| Lighting pass resolution scale |
| Distance rejection threshold |
| Normal weighting |
| Probe texture visualisation |
| Visualisation scaling |
| Per-volume statistics |
| Report DDGI memory usage |
The RTXGI plugin is enabled by default. See Dynamic DDGI and Global Illumination.
Ambient occlusion
Variable | Default | Purpose |
|---|---|---|
| 0 | Enable HBAO+. Multiplies over the screen-space AO buffer. |
| 0 | 0 = FP16 internal depth, 1 = FP32. Use FP32 to avoid self-occlusion banding on distant objects. |
| 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.
Tessellation
Variable | Default | Purpose |
|---|---|---|
| 48.0 | Global tessellation factor multiplier. Lower means more triangles. |
See Tessellation.
Hair
Variable | Purpose |
|---|---|
| Debug render mode. 0 = off, 1 = simulation strands, 2 = render strands with simulation influence, 3 = hair UV, 4 = root UV, 5 = seed, 6 = dimensions |
| Frustum culling for interpolation. Default 1. |
| Morph target mesh visualisation |
See Hair Rendering.
Volumetric fog
Variable | Purpose |
|---|---|
| Ray traced volumetric fog mode |
| Render volumetric fog at output rather than internal resolution |
Profiling
Standard Unreal, but worth having in one place:
Command | Shows |
|---|---|
| Frame, Game, Draw, GPU and RHIT timings. Start here. |
| The same over time |
| Game thread breakdown |
| Render thread breakdown |
| GPU pass breakdown |
| Physics solver time |
| RHI resource statistics |
| Memory usage |
| Single-frame GPU capture |
| Recompile modified shaders |
| Recompile global shaders |
See Profiling.
Finding variables yourself
Command | Effect |
|---|---|
| Dumps all console variables and commands to the log |
| Autocomplete in the console |
| Prints the current value and help text |
| Lists commands |