Light3D

Inherits: VisualInstance3D < Node3D < Node < Object

Inherited By: DirectionalLight3D, OmniLight3D, SpotLight3D

Provides a base class for different kinds of light nodes.

Description

Light3D is the abstract base class for light nodes. As it can't be instantiated, it shouldn't be used directly. Other types of light nodes inherit from it. Light3D contains the common variables and parameters used for lighting.

Tutorials

Properties

float

distance_fade_begin

40.0

bool

distance_fade_enabled

false

float

distance_fade_length

10.0

float

distance_fade_shadow

50.0

bool

editor_only

false

float

light_angular_distance

0.0

BakeMode

light_bake_mode

2

Color

light_color

Color(1, 1, 1, 1)

int

light_cull_mask

4294967295

float

light_energy

1.0

float

light_indirect_energy

1.0

float

light_intensity_lumens

float

light_intensity_lux

bool

light_negative

false

Texture2D

light_projector

float

light_size

0.0

float

light_specular

0.5

float

light_temperature

float

light_volumetric_fog_energy

1.0

float

shadow_bias

0.1

float

shadow_blur

1.0

bool

shadow_enabled

false

float

shadow_normal_bias

1.0

float

shadow_opacity

1.0

bool

shadow_reverse_cull_face

false

float

shadow_transmittance_bias

0.05

Methods

Color

get_correlated_color ( ) const

float

get_param ( Param param ) const

void

set_param ( Param param, float value )

Enumerations

enum Param:

enum BakeMode:

  • BAKE_DISABLED = 0 --- Light is ignored when baking. This is the fastest mode, but the light will be taken into account when baking global illumination. This mode should generally be used for dynamic lights that change quickly, as the effect of global illumination is less noticeable on those lights.

Note: Hiding a light does not affect baking LightmapGI. Hiding a light will still affect baking VoxelGI and SDFGI (see [member Environment.sdfgi_enabled).

  • BAKE_STATIC = 1 --- Light is taken into account in static baking (VoxelGI, LightmapGI, SDFGI (Environment.sdfgi_enabled)). The light can be moved around or modified, but its global illumination will not update in real-time. This is suitable for subtle changes (such as flickering torches), but generally not large changes such as toggling a light on and off.

  • BAKE_DYNAMIC = 2 --- Light is taken into account in dynamic baking (VoxelGI and SDFGI (Environment.sdfgi_enabled) only). The light can be moved around or modified with global illumination updating in real-time. The light's global illumination appearance will be slightly different compared to BAKE_STATIC. This has a greater performance cost compared to BAKE_STATIC.

Property Descriptions

  • float distance_fade_begin

Default

40.0

Setter

set_distance_fade_begin(value)

Getter

get_distance_fade_begin()

The distance from the camera at which the light begins to fade away (in 3D units).

Note: Only effective for OmniLight3D and SpotLight3D.

  • bool distance_fade_enabled

Default

false

Setter

set_enable_distance_fade(value)

Getter

is_distance_fade_enabled()

If true, the light will smoothly fade away when far from the active Camera3D starting at distance_fade_begin. This acts as a form of level of detail (LOD). The light will fade out over distance_fade_begin + distance_fade_length, after which it will be culled and not sent to the shader at all. Use this to reduce the number of active lights in a scene and thus improve performance.

Note: Only effective for OmniLight3D and SpotLight3D.

  • float distance_fade_length

Default

10.0

Setter

set_distance_fade_length(value)

Getter

get_distance_fade_length()

Distance over which the light and its shadow fades. The light's energy and shadow's opacity is progressively reduced over this distance and is completely invisible at the end.

Note: Only effective for OmniLight3D and SpotLight3D.

  • float distance_fade_shadow

Default

50.0

Setter

set_distance_fade_shadow(value)

Getter

get_distance_fade_shadow()

The distance from the camera at which the light's shadow cuts off (in 3D units). Set this to a value lower than distance_fade_begin + distance_fade_length to further improve performance, as shadow rendering is often more expensive than light rendering itself.

Note: Only effective for OmniLight3D and SpotLight3D, and only when shadow_enabled is true.

Default

false

Setter

set_editor_only(value)

Getter

is_editor_only()

If true, the light only appears in the editor and will not be visible at runtime.

  • float light_angular_distance

Default

0.0

Setter

set_param(value)

Getter

get_param()

The light's angular size in degrees. Increasing this will make shadows softer at greater distances. Only available for DirectionalLight3Ds. For reference, the Sun from the Earth is approximately 0.5.

Default

2

Setter

set_bake_mode(value)

Getter

get_bake_mode()

The light's bake mode. This will affect the global illumination techniques that have an effect on the light's rendering. See BakeMode.

Note: Meshes' global illumination mode will also affect the global illumination rendering. See GeometryInstance3D.gi_mode.

Default

Color(1, 1, 1, 1)

Setter

set_color(value)

Getter

get_color()

The light's color. An overbright color can be used to achieve a result equivalent to increasing the light's light_energy.

  • int light_cull_mask

Default

4294967295

Setter

set_cull_mask(value)

Getter

get_cull_mask()

The light will affect objects in the selected layers.

Default

1.0

Setter

set_param(value)

Getter

get_param()

The light's strength multiplier (this is not a physical unit). For OmniLight3D and SpotLight3D, changing this value will only change the light color's intensity, not the light's radius.

  • float light_indirect_energy

Default

1.0

Setter

set_param(value)

Getter

get_param()

Secondary multiplier used with indirect light (light bounces). Used with VoxelGI and SDFGI (see Environment.sdfgi_enabled).

Note: This property is ignored if light_energy is equal to 0.0, as the light won't be present at all in the GI shader.

  • float light_intensity_lumens

Setter

set_param(value)

Getter

get_param()

Used by positional lights (OmniLight3D and SpotLight3D) when ProjectSettings.rendering/lights_and_shadows/use_physical_light_units is true. Sets the intensity of the light source measured in Lumens. Lumens are a measure of luminous flux, which is the total amount of visible light emitted by a light source per unit of time.

For SpotLight3Ds, we assume that the area outside the visible cone is surrounded by a perfect light absorbing material. Accordingly, the apparent brightness of the cone area does not change as the cone increases and decreases in size.

A typical household lightbulb can range from around 600 lumens to 1,200 lumens, a candle is about 13 lumens, while a streetlight can be approximately 60,000 lumens.

  • float light_intensity_lux

Setter

set_param(value)

Getter

get_param()

Used by DirectionalLight3Ds when ProjectSettings.rendering/lights_and_shadows/use_physical_light_units is true. Sets the intensity of the light source measured in Lux. Lux is a measure pf luminous flux per unit area, it is equal to one lumen per square metre. Lux is the measure of how much light hits a surface at a given time.

On a clear sunny day a surface in direct sunlight may be approximately 100,000 lux, a typical room in a home may be approximately 50 lux, while the moonlit ground may be approximately 0.1 lux.

  • bool light_negative

Default

false

Setter

set_negative(value)

Getter

is_negative()

If true, the light's effect is reversed, darkening areas and casting bright shadows.

Setter

set_projector(value)

Getter

get_projector()

Texture2D projected by light. shadow_enabled must be on for the projector to work. Light projectors make the light appear as if it is shining through a colored but transparent object, almost like light shining through stained-glass.

Note: Unlike BaseMaterial3D whose filter mode can be adjusted on a per-material basis, the filter mode for light projector textures is set globally with ProjectSettings.rendering/textures/light_projectors/filter.

Default

0.0

Setter

set_param(value)

Getter

get_param()

The size of the light in Godot units. Only available for OmniLight3Ds and SpotLight3Ds. Increasing this value will make the light fade out slower and shadows appear blurrier. This can be used to simulate area lights to an extent.

Default

0.5

Setter

set_param(value)

Getter

get_param()

The intensity of the specular blob in objects affected by the light. At 0, the light becomes a pure diffuse light. When not baking emission, this can be used to avoid unrealistic reflections when placing lights above an emissive surface.

  • float light_temperature

Setter

set_temperature(value)

Getter

get_temperature()

Sets the color temperature of the light source, measured in Kelvin. This is used to calculate a correlated color temperature which tints the light_color.

The sun on a cloudy day is approximately 6500 Kelvin, on a clear day it is between 5500 to 6000 Kelvin, and on a clear day at sunrise or sunset it ranges to around 1850 Kelvin.

  • float light_volumetric_fog_energy

Default

1.0

Setter

set_param(value)

Getter

get_param()

Secondary multiplier multiplied with light_energy then used with the Environment's volumetric fog (if enabled). If set to 0.0, computing volumetric fog will be skipped for this light, which can improve performance for large amounts of lights when volumetric fog is enabled.

Note: To prevent short-lived dynamic light effects from poorly interacting with volumetric fog, lights used in those effects should have light_volumetric_fog_energy set to 0.0 unless Environment.volumetric_fog_temporal_reprojection_enabled is disabled (or unless the reprojection amount is significantly lowered).

Default

0.1

Setter

set_param(value)

Getter

get_param()

Used to adjust shadow appearance. Too small a value results in self-shadowing ("shadow acne"), while too large a value causes shadows to separate from casters ("peter-panning"). Adjust as needed.

Default

1.0

Setter

set_param(value)

Getter

get_param()

Blurs the edges of the shadow. Can be used to hide pixel artifacts in low-resolution shadow maps. A high value can impact performance, make shadows appear grainy and can cause other unwanted artifacts. Try to keep as near default as possible.

  • bool shadow_enabled

Default

false

Setter

set_shadow(value)

Getter

has_shadow()

If true, the light will cast real-time shadows. This has a significant performance cost. Only enable shadow rendering when it makes a noticeable difference in the scene's appearance, and consider using distance_fade_enabled to hide the light when far away from the Camera3D.

  • float shadow_normal_bias

Default

1.0

Setter

set_param(value)

Getter

get_param()

Offsets the lookup into the shadow map by the object's normal. This can be used to reduce self-shadowing artifacts without using shadow_bias. In practice, this value should be tweaked along with shadow_bias to reduce artifacts as much as possible.

Default

1.0

Setter

set_param(value)

Getter

get_param()

The opacity to use when rendering the light's shadow map. Values lower than 1.0 make the light appear through shadows. This can be used to fake global illumination at a low performance cost.

  • bool shadow_reverse_cull_face

Default

false

Setter

set_shadow_reverse_cull_face(value)

Getter

get_shadow_reverse_cull_face()

If true, reverses the backface culling of the mesh. This can be useful when you have a flat mesh that has a light behind it. If you need to cast a shadow on both sides of the mesh, set the mesh to use double-sided shadows with GeometryInstance3D.SHADOW_CASTING_SETTING_DOUBLE_SIDED.

  • float shadow_transmittance_bias

Default

0.05

Setter

set_param(value)

Getter

get_param()

Method Descriptions

  • Color get_correlated_color ( ) const

Returns the Color of an idealized blackbody at the given light_temperature. This value is calculated internally based on the light_temperature. This Color is multiplied by light_color before being sent to the RenderingServer.

Returns the value of the specified Param parameter.

Sets the value of the specified Param parameter.