giVolume
A box that scales the indirect (bounced) light of HD's ray-traced GI, like a post-process volume's indirect lighting intensity.
The box comes from the entity's transform (its position, rotation and scale) and size. mode picks camera (default) or region; blend is the soft edge in metres; indirectIntensity is 0..16 (1 changes nothing). Up to 8 volumes of each mode count; overlapping volumes multiply. With probeSpacing the box carries its own GI probes, which move with it (a vehicle's cab). Drawn only by HD (hd-only-ignored on other profiles).
Use it in a scene entity's components list as { "type": "giVolume", … }. The contract writes the fields flat and refuses unknown keys.
Fields
| Field | Type | Required | Default | Allowed values | Description |
|---|---|---|---|---|---|
size | Vec3 | yes | Full extents of the box along the entity's local axes before its scale, metres; each more than 0. | ||
indirectIntensity | number | yes | Multiplier on the indirect diffuse light, 0..16. 1 changes nothing. | ||
blend | number | no | 0 | Width of the soft edge, metres, 0 or more. Default 0.5. In camera mode the band OUTSIDE the box over which the effect fades to nothing as the camera moves away; in region mode the band INSIDE the box's faces. In region mode at most half the smallest extent. | |
mode | GiVolumeMode | no | camera, region | camera (default): the effect applies to the whole view, weighted by where the camera is: full inside the box, fading over blend metres outside (like a post-process volume: walking into a room changes the whole frame smoothly). region: the effect applies only to the surfaces inside the box. | |
probeSpacing | number | no | Give the box its own GI probes this far apart, metres, 0.1..2 (0.25 suits a car's cab): a grid fixed in the box that moves and turns with the entity and is re-traced every frame, which the GI inside the box reads instead of the world's. For an interior that moves (a vehicle's cab, a lift, a ship's bridge): the world's probes stay put as it passes through them, so they hold the light of wherever it just was and leak it through the walls as blotches. Absent: the world's probes. At most 16 along an axis and 1024 in all volumes together (the grid is thinned to fit); only the first 4 volumes with one count (gi-volume-limit). Works in either mode; indirectIntensity still applies. |
Example
From the contract's tested fixture fixtures/contract/full20/scene.json#wall-north.
{
"type": "giVolume",
"size": [
40,
4,
4
],
"indirectIntensity": 0.5,
"blend": 1,
"mode": "region"
}