GIProbe

Inherits: VisualInstance < CullInstance < Spatial < Node < Object

Real-time global illumination (GI) probe.

Description

GIProbes are used to provide high-quality real-time indirect light to scenes. They precompute the effect of objects that emit light and the effect of static geometry to simulate the behavior of complex light in real-time. GIProbes need to be baked before using, however, once baked, dynamic objects will receive light from them. Further, lights can be fully dynamic or baked.

Having GIProbes in a scene can be expensive, the quality of the probe can be turned down in exchange for better performance in the ProjectSettings using ProjectSettings.rendering/quality/voxel_cone_tracing/high_quality.

Procedural generation: GIProbe can be baked in an exported project, which makes it suitable for procedurally generated or user-built levels as long as all the geometry is generated in advance.

Performance: GIProbe is relatively demanding on the GPU and is not suited to low-end hardware such as integrated graphics (consider BakedLightmap instead). To provide a fallback for low-end hardware, consider adding an option to disable GIProbe in your project's options menus. A GIProbe node can be disabled by hiding it.

Note: Meshes should have sufficiently thick walls to avoid light leaks (avoid one-sided walls). For interior levels, enclose your level geometry in a sufficiently large box and bridge the loops to close the mesh. To further prevent light leaks, you can also strategically place temporary MeshInstance nodes with GeometryInstance.use_in_baked_light enabled. These temporary nodes can then be hidden after baking the GIProbe node.

Note: Due to a renderer limitation, emissive ShaderMaterials cannot emit light when used in a GIProbe. Only emissive SpatialMaterials can emit light in a GIProbe.

Tutorials

Properties

float

bias

1.5

bool

compress

false

GIProbeData

data

int

dynamic_range

4

float

energy

1.0

Vector3

extents

Vector3( 10, 10, 10 )

bool

interior

false

float

normal_bias

0.0

float

propagation

0.7

Subdiv

subdiv

1

Methods

void

bake ( Node from_node=null, bool create_visual_debug=false )

void

debug_bake ( )

Enumerations

enum Subdiv:

  • SUBDIV_64 = 0 --- Use 64 subdivisions. This is the lowest quality setting, but the fastest. Use it if you can, but especially use it on lower-end hardware.

  • SUBDIV_128 = 1 --- Use 128 subdivisions. This is the default quality setting.

  • SUBDIV_256 = 2 --- Use 256 subdivisions.

  • SUBDIV_512 = 3 --- Use 512 subdivisions. This is the highest quality setting, but the slowest. On lower-end hardware, this could cause the GPU to stall.

  • SUBDIV_MAX = 4 --- Represents the size of the Subdiv enum.

Property Descriptions

Default

1.5

Setter

set_bias(value)

Getter

get_bias()

Offsets the lookup of the light contribution from the GIProbe. This can be used to avoid self-shadowing, but may introduce light leaking at higher values. This and normal_bias should be played around with to minimize self-shadowing and light leaking.

Note: bias should usually be above 1.0 as that is the size of the voxels.


Default

false

Setter

set_compress(value)

Getter

is_compressed()

Deprecated. This property has been deprecated due to known bugs and no longer has any effect when enabled.


Setter

set_probe_data(value)

Getter

get_probe_data()

The GIProbeData resource that holds the data for this GIProbe.


  • int dynamic_range

Default

4

Setter

set_dynamic_range(value)

Getter

get_dynamic_range()

The maximum brightness that the GIProbe will recognize. Brightness will be scaled within this range.


Default

1.0

Setter

set_energy(value)

Getter

get_energy()

Energy multiplier. Makes the lighting contribution from the GIProbe brighter.


Default

Vector3( 10, 10, 10 )

Setter

set_extents(value)

Getter

get_extents()

The size of the area covered by the GIProbe. If you make the extents larger without increasing the subdivisions with subdiv, the size of each cell will increase and result in lower detailed lighting.


Default

false

Setter

set_interior(value)

Getter

is_interior()

If true, ignores the sky contribution when calculating lighting.


Default

0.0

Setter

set_normal_bias(value)

Getter

get_normal_bias()

Offsets the lookup into the GIProbe based on the object's normal direction. Can be used to reduce some self-shadowing artifacts.


Default

0.7

Setter

set_propagation(value)

Getter

get_propagation()

How much light propagates through the probe internally. A higher value allows light to spread further.


Default

1

Setter

set_subdiv(value)

Getter

get_subdiv()

Number of times to subdivide the grid that the GIProbe operates on. A higher number results in finer detail and thus higher visual quality, while lower numbers result in better performance.

Method Descriptions

  • void bake ( Node from_node=null, bool create_visual_debug=false )

Bakes the effect from all GeometryInstances marked with GeometryInstance.use_in_baked_light and Lights marked with either Light.BAKE_INDIRECT or Light.BAKE_ALL. If create_visual_debug is true, after baking the light, this will generate a MultiMesh that has a cube representing each solid cell with each cube colored to the cell's albedo color. This can be used to visualize the GIProbe's data and debug any issues that may be occurring.

Note: bake works from the editor and in exported projects. This makes it suitable for procedurally generated or user-built levels. Baking a GIProbe generally takes from 5 to 20 seconds in most scenes. Reducing subdiv can speed up baking.


  • void debug_bake ( )

Calls bake with create_visual_debug enabled.