SpotLight

SpotLight nodes create a point in 3D space that emits a cone-shaped light in a given direction. A real world example of a spot light is a desk lamp.

See also DirectLight, EnvironmentLight, and PointLight.

Tip:  SpotLight's classic 3D system equivalent is the Spot node.

Inputs and Controls

Connection Type

Connection Name

Function

Input

look An optional input to force the light to "look" at an Axis node.
axis

An optional input to link the position, rotation, scale, and skew of the transformed 3D object(s) to an Axis node, so that the transformation controls on the Axis node override the corresponding controls on this node.

Tip:  If you’ve worked with other 3D applications, you may know the Axis node as a “null” or “locator” object.

Control (UI)

Knob (Scripting)

Default Value

Function

SpotLight Tab

Cone Angle

cone_angle

0

Sets the spot light cone angle, which adjusts the spread of the light. Valid angles are from 0 to 90 degrees.

Cone Softness

cone_softness

0

Unsupported in the current USD library version used in Nuke.
Focus focus 0

Sets the brightness of the light as a direct source of light, such as a desk lamp.

Focus Tint focus_tint 1 Unsupported in the current USD library version used in Nuke.
IES Angle Scale ies_angle_scale 0 Unsupported in the current USD library version used in Nuke.
IES File ies_file none Unsupported in the current USD library version used in Nuke.
IES Normalize ies_normalize off Unsupported in the current USD library version used in Nuke.

Color

color

1

Sets the color of the light.

Intensity

intensity

1

Sets the brightness of the light.

Enable Color Temperature

enable_color_temperature

off

Unsupported in the current USD library version used in Nuke.

Color Temperature

color_temperature

1

Unsupported in the current USD library version used in Nuke.

Exposure

exposure

0

Sets the brightness of the light as an indirect or ambient source of light, such as light reflected from the environment where the light is located.

Normalize

normalize

off

Unsupported in the current USD library version used in Nuke.

Diffuse

diffuse

1

Sets the amount of diffuse reflection created by the light, such as light bouncing off soft furnishings and clothing.

Specular

specular

1

Sets the amount of specular reflection created by the light, such as light bouncing off metal and other highly reflective surfaces.

Display

display

wireframe

Adjust the display characteristics of the 3D object. These settings don’t affect the render output of the scene; these are for display purposes only in the 3D Viewer.

off - hides the 3D geometry object.

wireframe - displays only the outlines of the object’s geometry.

solid - displays all geometry with a solid color.

solid + wireframe - displays the geometry as solid color with the object’s geometry outlines.

textured - displays only the surface texture.

textured + wireframe - displays the wireframe plus the surface texture.

Note:  The Viewer node 3D > display setting overrides this control.

Selectable

selectable

on

When enabled, you can make selections as normal in the Viewer. When disabled, points cannot be selected or changed.

file_menu

N/A

Select to import or export a channel file:

Import chan file - import a channel file and transform the object according to the transformation data in the channel file. Channel files contain a set of Cartesian coordinates for every frame of animation in a given shot. You can create and export them using Nuke or 3D tracking software, such as 3D-Equalizer, Maya, or Boujou.

Export chan file - export the translation parameters that you’ve applied to the object as a channel file. This is a useful method of sharing setups between artists.

snap_menu

N/A

Choose what a selection in the Viewer or pivot point is snapped to in the Viewer:

Geo to Selection (position) - the object is snapped to a new position depending on the points selected.

Geo to Selection (position, orientation) - the object is snapped to a new position and orientation depending on the points selected.

Geo to Selection (position, orientation, size) - the object is snapped to a new position, orientation, and size depending on the points selected.

Pivot Point to Selection (position) - the pivot point is snapped to a new position depending on the points selected.

Pivot Point to Selection (position, orientation) - the pivot point is snapped to a new position and orientation depending on the points selected.

Pivot Point to Selection (orientation) - the pivot point is snapped to a new position, orientation, and size depending on the points selected.

Transform Order

xform_order

SRT

Sets the operation order for scale (S), rotation (R), and translation (T). The possible operation combinations are SRT, STR, RST, RTS, TSR, TRS.

Rotation Order

rot_order

ZXY

Sets the order of rotation. The possible axial combinations are ZXY, XYZ, XZY, YXZ, YZX, ZXY, ZYX.

Translate

translate

0, 0, 0

Lets you translate the object along the x, y, and z axes. You can also adjust translate values by clicking and dragging the object in the 3D Viewer.

Rotate

rotate

0, 0, 0

Lets you rotate the object around the x, y, and z axes. You can adjust rotate values by holding down Ctrl/Cmd and dragging in the 3D Viewer.

Scale

scaling

1, 1, 1

Lets you scale the object on the x, y, and z axes.

Uniform Scale

uniform_scale

1

Lets you scale the object simultaneously on the x, y, and z axes.

Skew

skew

0, 0, 0

Lets you skew the object on the x, y, and z axes.

Pivot Translate

pivot_translate

0, 0, 0

When you make changes to a 3D object’s position, scaling, skewing, and rotation, these occur from the location of the object’s origin point or pivot. The pivot translate and rotate x, y, and z controls allow you to move and rotate the pivot point as required - you can even move it outside of the object. Subsequent transformations applied then occur relative to the new pivot point location and rotation.

You can hold down Ctrl/Cmd and drag the pivot point to a new location in the 3D Viewer.

Pivot Rotate

pivot_rotate

0, 0, 0

Local Matrix

Specify Matrix

useMatrix

N/A

Enable this control to specify matrix values for the object you’re transforming as an alternative to setting transform, scale, skew and pivot values above.

matrix

matrix

N/A

The matrix displays values from the object’s transform, rotate, scale, skew, and pivot controls.

Check Specify Matrix and copy or drag-and-drop matrix values from another object to apply those values, for example, if you wanted to align objects in a scene.

World Matrix

matrix

matrix

N/A

Displays the world or absolute xyz transform of the node in world coordinates.

Note:  Unlike the Local matrix, you can’t adjust the World matrix manually.

Shadows Tab

cast shadows

cast_shadows

disabled

When enabled, the light casts shadow as defined by the Shadow controls.

shadow mode

shadow_mode

solid

Presents three shadow casting modes that affect shadows cast by objects, based on the objects’ opacity:

solid - objects that cast shadows are considered to be completely solid. This option can be used with both ScanlineRender and PrmanRender.

clipped alpha - objects that cast shadows are considered to be transparent if the object’s alpha is below the light’s clipping threshold control in the Shadows tab. This option is only relevant if you are using ScanlineRender to render your shadows.

full alpha - shadows are calculated based on how light is reduced when it passes through non-opaque occluders. This option is only relevant if you are using ScanlineRender to render your shadows.

filter

filter

cubic

Determines the type of filter that the shadow mode uses when it’s set to clipped alpha or full alpha.

scene epsilon

scene_epsilon

0.001

An offset that moves the sampling point away from the geometry surface, towards the light that is casting the shadow. Increasing this value can reduce self-shadowing artifacts.

This only applies if your shadows are generated using depth mapping and shadow mode is set to full alpha.

samples

samples

1

Sets the number of samples for the light when generating soft shadows. If soft shadows in your scene appear dotty or noisy, try increasing this value. The higher the value, the smoother the soft the shadows become.

This only applies when shadow mode is set to solid or clipped alpha.

sample width

sample_width

1

Sets the size of the light for soft shadows. This value determines the width of the soft area around the egde of a shadow. The higher the value, the larger the soft area.

This control is only relevant if your shadows are generated using raytracing.

bias

depthmap_bias

0.01

Sets the bias for the raytracing or shadow map. Increase this value if self shadowing artifacts appear in the image. This moves the surface sample point away from surface. Note, however, that if you increase the value too much, some shadows may start moving away from the base of the objects that cast them.

This only applies when shadow mode is set to solid or clipped alpha.

slope bias

depthmap_slope_
bias

0.001

Bias for the shadow map. This is like bias, but the offset is proportional to the slope of the depth map. This allows you to give a different offset to each value in the depth map, depending on the surface’s slope relative to the light.

If increasing bias reduced the existing self-shadowing artifacts but introduced more artifacts in other areas of the image, you may want to bring bias down a little and increase slope bias instead.

This only applies if your shadows are generated using depth mapping and shadow mode is set to solid or clipped alpha.

clipping threshold

clipping_threshold

0.5

Objects that are set to cast shadows are considered solid if their alpha is below the value set here.

This only applies if your shadows are generated using depth mapping and shadow mode is set to clipped alpha.

jitter scale

shadow_jitter_scale

3

Sets the amount of jitter used when doing percentage-closer filtering (PCF) for soft shadows. A larger jitter scale value results in softer, more perceptually accurate shadows.

PCF works by sampling the depth map at many different positions around the same spot. The final shadow value for that spot is an average of how many of the samples were occluded or visible from point of view of the light.

This control is only relevant if your shadows are generated using depth mapping and shadow mode is set to solid or clipped alpha.

depthmap resolution

depthmap_width

1024

Sets the resolution of the depth map. Larger values will result in a less crunchy edge, but will require more time to process.

Note that you can also fix crunchy edges by increasing the number of samples instead of increasing the depth map resolution.

This control is only relevant if your shadows are generated using depth mapping and shadow mode is set to solid or clipped alpha.

output mask

shadow_mask

disabled

Enables the associated channel to the right. Disabling this checkbox is the same as setting the channel to none.

none

Sets the channel you want to output the shadow map into. This can be enabled even if the cast shadows box is disabled.

Step-by-Step Guides

Inserting Spot Lights