Ue Uds Setup And Modes

UDS setup and top-level modes

UDS replaces Unreal's stock sky/lighting stack with one actor and four cross-cutting mode dials. This skill covers getting the actor into a level cleanly and choosing the Sky / Color / Project / Feature Level combination for the project.

When to use this skill

• Dragging UDS into a fresh level for the first time, or getting "missing/dark scene" on a level that just got UDS.
• Choosing between Volumetric, Static, 2D Dynamic, Voxel, Aurora, or Space cloud modes.
• Targeting mobile/console — making sure incompatible features are swapped out.
• Switching to/from Cinematic Project Mode before rendering a film.
• Anything in the Basic Controls category of UDS.

Adding UDS to a level

Before dragging the actor in, remove from the level:

• Directional Lights
• Sky Light
• Exponential Height Fog
• Sky Atmosphere
• Volumetric Cloud

If ambient light remains after removing those, static light is baked into the level's lightmaps — run Build → Build Lighting to clear it.

Drag the Ultra Dynamic Sky actor from the Blueprints/ folder of the UDS plugin into the level. Daytime lighting with volumetric clouds should appear.

Place UDS at ground level.
Use Volumetric Clouds → Bottom Altitude to change cloud height,
NOT actor translation (which disturbs atmosphere/fog).

On first use the editor may need to compile shaders for UDS before features become visible. It will indicate this; it can take a while depending on hardware.

Basic Controls category

The Basic Controls category also has an advanced dropdown that holds the configuration override option — see ue-uds-modifiers-configs-state.

Sky Mode

Voxel Clouds shares most settings with Volumetric Clouds (textures, altitude, colors) and is affected by the Volumetric Cloud Painter and Radial Storm local coverage.

Color Mode

If the project setting Support Sky Atmosphere Affecting Height Fog is on (default + recommended), fog colors come from the sky atmosphere and most Fog Color settings on UDS are ignored. Disable that project setting for full direct fog color control. Simplified Color disables the sky atmosphere entirely, so all Fog Color settings become live.

Project Mode

Switch Cinematic Mode back to Game / Real-time after rendering — Cinematic's quality bumps will tank live perf.

The Cinematic / Offline Mode category has additional knobs for offline-only quality.

Feature Level

Feature Level should match the renderer feature level the build targets. With Mobile selected, incompatible Sky Modes (Volumetric Clouds, Volumetric Aurora) auto-swap at runtime for mobile-compatible replacements, configured in the Mobile category.

For multi-platform projects, set Feature Level from Platform Name at startup — the Platform Feature Levels map in the Mobile category. Without this, the blueprint may activate features the platform can't render, causing visual bugs.

Runtime / Blueprint control

All four modes are exposed variables on the UDS actor.

// Get a UDS reference from any blueprint:
UDS = GetUltraDynamicSky()

// Setting modes at runtime:
UDS.SkyMode      = ESkyMode::VolumetricClouds
UDS.ColorMode    = EColorMode::Simplified
UDS.ProjectMode  = EProjectMode::Game
UDS.FeatureLevel = EFeatureLevel::Mobile
UDS.CloudCoverage = 0.6      // ignored if UDW present
UDS.Fog           = 0.2      // ignored if UDW present

Most "active" properties (Time of Day, Cloud Coverage, Fog, sun/moon colors) update naturally via the cache system. Some are static properties that apply once at startup and don't auto-refresh — if a runtime change has no effect, call the matching Static Properties - <Category> function (e.g. Static Properties - Sun). For a complete instant refresh, call Hard Reset Cache. See ue-uds-performance-mobile-troubleshooting.

Quick decision guide

• Targeting consoles/PC, want it to look great → Volumetric Clouds + Sky Atmosphere + Game / Real-time.
• Mobile build → Feature Level = Mobile. Mobile category picks the cloud replacement (Static or 2D Dynamic).
• Rendering a film/cinematic → Project Mode = Cinematic / Offline before, Game / Real-time after.
• Stylized voxel game → Sky Mode = Voxel Clouds.
• Space scene → Sky Mode = Space. See ue-uds-sun-moon-stars for stars/space layer.
• Aurora is the hero effect → Sky Mode = Volumetric Aurora (no clouds); for 2D aurora in any mode enable Use Auroras in the Aurora category.
• Cheap sky for low-end hardware → No Clouds + Simplified Color + Game / Real-time.

Gotchas

• Scene renders black after adding UDS — exposure. Disable any post process volume that overrides exposure; in the viewport's Lit dropdown check Game Settings for exposure; or on UDS disable Apply Exposure Settings in the Exposure category. (See ue-uds-lighting-and-shadows.)
• Moving the UDS actor to change cloud height — wrong knob. Use Bottom Altitude in Volumetric Clouds; moving the actor breaks atmosphere/fog.
• Mobile features missing or rendering wrong — Feature Level is not set to Mobile. The blueprint will try to activate desktop-only features on the mobile renderer, causing visual bugs.
• Cinematic mode left on after a render → live FPS tanks because quality settings stay bumped at runtime. Always switch back.
• Cloud Coverage / Fog ignored on UDS — UDW is in the scene. Set them on UDW's weather state instead (see ue-udw-setup-and-state).
• Setting Sky Mode while a Radial Storm or Volumetric Cloud Painter is in use, on a non-Volumetric mode — the distant-storm visuals only work with Volumetric Clouds; on other modes the storm still affects state but renders no distant visible storm.

References & source material

Docs (Ultra Dynamic Sky 9.5):

• Adding Ultra Dynamic Sky to Your Level
• Basic Controls
• Sky Mode
• Color Mode
• Project Mode
• Feature Level
• Considerations for Mobile

Plugin asset paths:

• Blueprints/ — UDS actor (drag into level from here)
• Blueprints/Tools/ — editor utilities (Cloud Profile Authoring Tool, Static Clouds Authoring Tool, Configuration Manager, etc.)

Related skills: ue-uds-clouds, ue-uds-fog-and-atmosphere, ue-uds-time, ue-uds-lighting-and-shadows, ue-uds-performance-mobile-troubleshooting, ue-uds-modifiers-configs-state.