Light Control Commands

This section documents runtime light manipulation commands (UE5.2+).

Overview

UnrealCV provides TCP commands for controlling scene lighting:

  • Directional Light: Sunlight intensity and shadow settings

  • Sky Light: Ambient/IBL intensity control

  • Shadow Quality: Deep shadow casting for better occlusion

Note

These commands operate on the scene’s default DirectionalLight and SkyLight actors. Custom lights require Blueprint API usage.

TCP Commands

Directional Light

vget /light/directional/intensity

Get directional light intensity (lux).

Returns: Intensity value (e.g., 3.00)

vset /light/directional/intensity [Intensity]

Set directional light intensity.

Arguments: - Intensity: Lux value (typical range: 0.0-10.0)

Example: vset /light/directional/intensity 3.0

Returns: Set DirectionalLight intensity to 3.00

Deep Shadow

vget /light/directional/castdeepshadow

Get directional light deep shadow casting status.

Returns: true or false

vset /light/directional/castdeepshadow [true|false]

Enable/disable directional light deep shadow casting.

Arguments: - true or 1 - Enable deep shadows - false or 0 - Disable deep shadows

Example: vset /light/directional/castdeepshadow true

Sky Light

vget /light/skylight/intensity

Get skylight intensity.

Returns: Intensity value (e.g., 1.00)

vset /light/skylight/intensity [Intensity]

Set skylight intensity.

Arguments: - Intensity: Multiplier value (typical range: 0.0-3.0)

Example: vset /light/skylight/intensity 1.0

Returns: Set SkyLight intensity to 1.00

Blueprint API

LightBPLib provides Blueprint-accessible functions.

SetDirectionalLightIntensity(WorldContext, Intensity) → bool

Set directional light intensity from Blueprint.

Parameters:

  • WorldContext – World context object

  • Intensity – Lux value

Returns:

true if successful

GetDirectionalLightIntensity(WorldContext) → float

Get directional light intensity.

Parameters:

WorldContext – World context object

Returns:

Current intensity in lux

SetSkyLightIntensity(WorldContext, Intensity) → bool

Set skylight intensity from Blueprint.

Parameters:

  • WorldContext – World context object

  • Intensity – Intensity multiplier

Returns:

true if successful

GetSkyLightIntensity(WorldContext) → float

Get skylight intensity.

Parameters:

WorldContext – World context object

Returns:

Current intensity multiplier

SetDirectionalLightCastDeepShadow(WorldContext, bCast) → bool

Enable/disable deep shadow casting.

Parameters:

  • WorldContext – World context object

  • bCast – true to enable deep shadows

Returns:

true if successful

GetDirectionalLightCastDeepShadow(WorldContext) → bool

Get deep shadow casting status.

Parameters:

WorldContext – World context object

Returns:

true if deep shadows enabled

Lighting Setup Notes

Directional Light Intensity Reference:

  • 0.5 - Dim indoor lighting

  • 1.0 - Overcast day

  • 3.0 - Typical daylight

  • 10.0 - Bright direct sunlight

Sky Light Intensity Reference:

  • 0.0 - No ambient light

  • 0.5 - Dark interior

  • 1.0 - Normal IBL

  • 2.0 - Bright interior with windows

Deep Shadows:

Enable for: - Accurate occlusion in depth/segmentation data - Realistic shadow relationships - Training data for depth estimation models

Disable for: - Faster rendering (during preview) - Situations where shadows cause ambiguity

Common Issues

Light commands have no effect

  • Ensure scene contains DirectionalLight and SkyLight actors

  • Check that lights are set as movable (not static)

  • Verify light intensity values are within valid range

Intensity values seem wrong

  • Directional light uses physical units (lux)

  • Sky light uses relative multiplier

  • Check UE5 lighting units settings in Project Settings

See Also