Gi And Bake Recipes
Global Illumination: VoxelGI vs SDFGI
Decision Matrix
| Feature | VoxelGI | SDFGI |
|---|---|---|
| Setup | Manual bounds per room | Automatic, scene-wide |
| Dynamic objects | Fully supported | Partially supported |
| Performance | Moderate | Higher cost |
| Use case | Indoor, small-medium scenes | Large outdoor scenes |
| Godot version | 4.0+ | 4.0+ |
VoxelGI Setup
# room_gi.gd - Place one VoxelGI per room/area
extends VoxelGI
func _ready() -> void:
# Tightly fit the room
size = Vector3(20, 10, 20)
# Quality settings
subdiv = VoxelGI.SUBDIV_128 # Higher = better quality, slower
# Bake GI data
bake()SDFGI Setup
# world_environment.gd
extends WorldEnvironment
func _ready() -> void:
var env := environment
# Enable SDFGI
env.sdfgi_enabled = true
env.sdfgi_use_occlusion = true
env.sdfgi_read_sky_light = true
# Cascades (auto-scale based on camera)
env.sdfgi_min_cell_size = 0.2 # Detail level
env.sdfgi_max_distance = 200.0LightmapGI (Baked Static Lighting)
When to Use
- Static architecture (buildings, dungeons)
- Mobile/low-end targets
- No dynamic geometry
Setup
# Scene structure:
# - LightmapGI node
# - StaticBody3D meshes with GeometryInstance3D.gi_mode = STATIC
# lightmap_baker.gd
extends LightmapGI
func _ready() -> void:
# Quality settings
quality = LightmapGI.BAKE_QUALITY_HIGH
bounces = 3 # Indirect light bounces
# Bake (editor only, not runtime)
# Click "Bake Lightmaps" button in editorReflectionProbe
For localized reflections (mirrors, shiny floors):
# reflection_probe.gd
extends ReflectionProbe
func _ready() -> void:
# Capture area
size = Vector3(10, 5, 10)
# Quality
resolution = ReflectionProbe.RESOLUTION_512
# Update mode
update_mode = ReflectionProbe.UPDATE_ONCE # Bake once
# or UPDATE_ALWAYS for dynamic reflections (expensive)