Nodes · 3D
Light3D
3Dv1app
Overview
A light in the scene — point, spot, distant (sun), rect, or dome (ambient). Authored as a standard UsdLux prim, so the viewport, Render3D, USD export and the Unreal bridge all read the same light. Zero lights in a scene = the neutral headlight rig.
Inputs
| Input | What it takes |
|---|---|
| in | the image this node works on |
Outputs
| Output | Type |
|---|---|
| out | Scene |
Parameters
| Parameter | Type | Default | What it does |
|---|---|---|---|
| type | Choice | point | What kind of light: point (a bulb, falls off by inverse-square), spot (point + cone), distant (parallel sun rays — position doesn't matter, rotation does), rect (a soft panel, single-sided), dome (even ambient fill everywhere). |
| intensity | Float | 1 | Linear brightness multiplier on the colour. For point/spot lights this is the value at 1 meter — expect to push it well past 1 to light something a few meters away. |
| exposure | Float | 0 | Stops on top of intensity: +1 doubles the light, −1 halves it. The knob a grade-minded artist reaches for. |
| color | Color | [1.0, 1.0, 1.0, 1.0] | Not documented yet. |
| radius | Float | 0.5 | The source's size in meters — and the floor on inverse-square falloff, so intensity stays finite right at the bulb. |
| cone_angle | Float | 25 | Spot only: the cone's half-angle in degrees off the light's aim (−Z). |
| cone_softness | Float | 0.2 | Spot only: how much of the cone's edge fades (0 hard … 1 fully soft). |
| width | Float | 1 | Rect only: panel width in meters. |
| height | Float | 1 | Rect only: panel height in meters. |
| shadow | Bool | false | Make this the shadow-casting KEY light. One light gets the 2k shadow map — the first enabled spot or distant in the scene; point/rect/dome can't cast in v1. |
| shadow_bias | Float | 0.0015 | Depth-compare trim against shadow acne (surfaces speckling in their own shadow). Raise it if flat surfaces sparkle; too high and shadows detach from their objects (peter-panning). |
| tx | Float | 0 | Translate X — position along the world X axis, metres. |
| ty | Float | 0 | Translate Y — position along the world Y axis (up), metres. |
| tz | Float | 0 | Translate Z — position along the world Z axis, metres. The camera looks down −Z. |
| rx | Float | 0 | Rotate around X, degrees. |
| ry | Float | 0 | Rotate around Y (turntable), degrees. |
| rz | Float | 0 | Rotate around Z (roll), degrees. |
| sx | Float | 1 | Scale along X. 1 = unchanged. |
| sy | Float | 1 | Scale along Y. |
| sz | Float | 1 | Scale along Z. |
See also
- The 3D system — How to put geometry, cameras and volumes in the comp — without becoming a 3D application.