Color / Red / Green / Blue
Sets the RGB color emitted by the Disk Light.
Use channel-specific controls when the operation should not affect all components equally.
← Fusion node reference
USD / 3DAdvanced
uDiskLight
Disk USD light
Adds a disk light source to a USD scene with color, exposure, response, falloff, shadow and transform controls.
uDiskLight
DaVinci Resolve · Fusion
uDiskLight is a USD scene light shaped as a disk. It controls direct illumination and specular response inside the stage, making it useful for physically understandable lighting, reflections and shadow design before uRenderer.
Overview
What uDiskLight does
uDiskLight is a USD scene light shaped as a disk. It controls direct illumination and specular response inside the stage, making it useful for physically understandable lighting, reflections and shadow design before uRenderer.
Mental model
Think of uDiskLight as a real disk lamp placed in the USD scene: size and shape define the character of highlights and shadows, while intensity, exposure and falloff define its energy.
Common uses
Add disk lighting to a USD shot
Shape diffuse illumination and specular reflections
Create controlled shadows
Balance intensity with exposure
Build studio-style USD lighting rigs
Flow anatomy
Inputs & outputs
The port structure shows how this node fits into a Fusion graph.
SceneInput
3D scene or object data to be processed or combined.
uDiskLight
Fusion node
SceneOutput
The resulting 3D scene or scene object.
Inspector
Important parameters
Start with these controls before reaching for more complicated workarounds.
Intensity
Sets the base energy of the light.
Exposure
Changes light energy in photographic stops.
Enable Color Temperature
Enables black-body color-temperature control for the Disk Light.
Diffuse Response
Sets how strongly the Disk Light contributes to diffuse shading.
Specular Response
Sets how strongly the Disk Light contributes to specular reflections.
Decay Type
Selects the light falloff model.
Chooses how light intensity falls off with distance.
Decay Rate
Sets how quickly the light falls off with distance.
Shaping Focus
Controls how tightly the Disk Light emission is focused.
Shaping Cone Angle
Sets the shaping cone angle of the Disk Light.
Normalize Intensity
Keeps Disk Light energy predictable as the emitter radius changes.
Radius
Sets disk size.
Enable Shadows
Turns shadow generation on or off.
Shadow Color / Red / Green / Blue
Sets the RGB tint of Disk Light shadows.
Use channel-specific controls when the operation should not affect all components equally.
Density
Sets the density of generated or distributed elements.
Softness
Softens the transition at the edge of the mask, matte or effect.
Softness Quality
Sets the processing quality for this operation.
Use a lighter setting while building the comp if needed, then verify the final-quality result before render.
Shadow Map Size
Sets the resolution of the shadow map.
Higher values can sharpen shadow detail but increase render cost.
Shadow Map Bias
Offsets shadow depth comparison to reduce self-shadowing artifacts.
Use the smallest value that removes acne or detached-looking shadows.
Shadow Map Offset
Sets the Shadow Map Offset.
Translation X / Y / Z
Sets translation on the X, Y and Z axes.
Pivot X / Y / Z
Sets the pivot position on the X, Y and Z axes.
Export as Separate Stage
Outputs this operation as a separate USD stage instead of folding it into the incoming stage.
Practical setup
A reliable workflow
- 1
Connect or create the USD stage.
- 2
Add uDiskLight and position it relative to the subject.
- 3
Set color, intensity and exposure before fine-tuning material response.
- 4
Choose decay behavior that fits the shot scale.
- 5
Adjust the shape-specific size controls for highlight and shadow character.
- 6
Enable shadows and tune softness only after the lighting direction is correct.
- 7
Render through uRenderer and judge the result on the final material.
Typical node chain
USD Scene→
uDiskLight→
uRenderer
Examples
Where this node fits in real work
Disk key light
Use uDiskLight as the main shaped source in a simple USD lighting rig.
uShape / uLoaderuDiskLightuCamerauRenderer
Material highlight test
Use the source to evaluate roughness and reflective response.
uMaterialuDiskLightuRenderer
Troubleshooting
Common mistakes
Compensating for poor placement with extreme intensity.
Judging the light without checking the target material roughness.
Enabling expensive shadows before the basic direction and exposure are established.
Production notes
Practical tips
Use exposure for large energy changes and intensity for fine adjustments.
Evaluate diffuse and specular response separately when matching a reference.
Keep lights on clearly named USD branches in larger scenes.
Related nodes