Search TipsViewer
The Viewer node displays the render output of any connected process nodes in the Viewer panel. It doesn’t alter data in any way, but simply allows you to view the effect of any changes you make upstream.
You can place as many Viewer nodes in a script as you wish, which allows you to simultaneously view multiple outputs. You can also connect the output from up to ten process nodes into single Viewer node, and then cycle through the various displays. This allows you to easily compare an image before and after processing by a given effect.
You can also create this node by:
• selecting Image > Viewer from the Nuke Toolbar, or
• pressing Ctrl/Cmd+I.
Inputs and Controls
|
Connection Type |
Connection Name |
Function |
|
Input |
unnamed |
The process node upstream to output to the Viewer. You can connect up to ten (0-9) nodes at once. |
|
Control (UI) |
Knob (Scripting) |
Default Value |
Function |
|
Viewer Tab |
|||
|
frame_range |
frame_range |
none |
Sets the first and last frame in the playback range. You can enter frame numbers here or Cmd+drag the red triangles in the timeline. |
|
frame_range_lock |
enabled |
Click to unlock or lock playback to the frame numbers specified in frame_range. |
|
|
<< >>increment |
frame_increment |
10 |
Sets the number of frames to step through using the Viewer << and >> buttons. |
|
channels |
channels |
rgba |
Sets the channels to display in the viewer. You can also select a channel from a different layer to display in the alpha channel. |
|
clip_warning |
clip_warning |
no warnings |
When set to exposure, any pixels that are outside the 0-1 range are Zebra-striped in the Viewer. |
|
gain |
gain |
1 |
Sets the amount of gain to multiply the image by before display. |
|
gamma |
gamma |
1 |
Sets the amount of gamma correction to apply to the image. Gamma correction is applied after the gain, viewerprocess, and any custom inputprocess. |
|
apply LUT to color channels only |
rgb_only |
disabled |
When enabled, the LUT is applied to color channels only. |
|
downrez |
downrez |
1 |
Sets the amount of down scaling applied before display. factor to speed up rendering. You can use downrez to speed up rendering, but bear in mind that it is multiplied into any global proxy scale that may also be in effect. |
|
ignore pixel aspect |
ignore_pixel_aspect |
disabled |
When enabled, output to the Viewer ignores the file’s pixel aspect ratio and always draws using square pixels. |
|
prevent auto zoom |
zoom_lock |
disabled |
When enabled, the Viewer is prevented from automatically adjusting the zoom level to fit new images into the Viewer when swapping between different sized images. |
|
show overscan |
show_overscan |
disabled |
When enabled, any overscan present is displayed in the Viewer. |
|
enable full frame processing |
full_frame_processing |
disabled |
When enabled, force Nuke to render every scanline in the image. Compared to the default mode, this may take slightly longer initially and requires more space in the Viewer cache, but once Nuke has cached the frames you require, you can pan around and change the zoom level without breaking the cache or affecting playback. |
|
overscan |
overscan |
100 |
Sets the amount of overscan to show in the Viewer when show overscan ins enabled. |
|
safe zone |
safe_zone |
no guides |
Sets the safe zone overlay to apply to the image: • no guides • title safe • action safe • format center |
|
format center |
format_center |
disabled |
When enabled, the center of the format is marked with a cross in the Viewer. |
|
mask region outside ratio |
masking_ratio |
square |
Sets the aspect ratio of the mask specified in the mask mode dropdown. |
|
mask mode |
masking_mode |
no mask |
Sets the mask overlay to apply to the image: • no mask • lines • half • full |
|
center f-stop |
center_fstop |
8 |
Sets the f-stop to display when gain is set to 1. You can use zero to show stops as +/-n. Note: If you want a non-integer value, enter a formula to get an accurate value, otherwise the display does not round to normal f-stop names. For instance, instead of 5.6 you would use pow(2,2.5) to get 5.65685 |
|
shutter angle |
shutter_angle |
180 |
Sets the camera shutter angle from 0-360 degrees. This is used in combination with the Viewer's playback fps setting to compute exposure values. |
|
gl buffer depth |
gl_buffer_depth |
float |
Sets the OpenGL buffer depth and enables the use of the GPU for the Viewer process and input process: • byte - converts to 8-bit with error diffusion. • half-float - converts to 16-bit (half) float. • float - uses a full 32-bit floating point texture (may be very slow on some cards). In half and full float modes, the GPU can be used to apply Viewer effects like gamma and the LUT in a Viewer process. Note: You can choose a default value for this setting in the Preferences or by using knobDefault() in a startup script. |
|
use GPU for viewer when possible |
useGPUForViewer |
enabled |
When enabled, Viewer effects (like gain, gamma, and viewer process node) are applied using the GPU when possible. The ’when possible’ clause is due to the fact that in some cases, like when broadcast monitor output is enabled or the GL buffer depth is 8-bit, effects must be computed in the CPU. |
|
use GPU for input when possible |
useGPUForInputs |
enabled |
When enabled, compute nodes connected to the Viewer input on the GPU when possible, though not all nodes have a GPU implementation. Normally, the Viewer only attempts to run its own effects (like gain, gamma, and viewer process node) on the GPU. Note: If nodes are computed on the GPU, the color values displayed in the Viewer are inaccurate since they show the color from the last node computed in the CPU, prior to transferring the image into the graphics card. |
|
disabled GPU dithering |
disableGPUDitherForViewer |
disabled |
When enabled, GPU dithering is allowed in the Viewer (which affects half-float and float modes). |
|
Note: When the Viewer AB mode is changed to wipe or stack, the state of the GPU acceleration controls is stored, GPU acceleration is turned off, and GPU acceleration is disabled. |
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|
viewer process |
viewerProcess |
sRGB |
Sets the Viewer Process operation applied to the viewed image before it is displayed on the screen. It is typically used to convert from linear to your monitor's colorspace. |
|
input process |
input_process_node |
VIEWER_INPUT |
Sets the name of a node to process through for viewing when the IP button is activated. If the node does not exist, the IP button has no effect. |
|
input_process |
disabled |
Applies the input process node before displaying the image. To define the node to use, enter its name in the input process field or, from the Node Graph right-click menu, select Edit > Node > Use as Input Process. |
|
|
input process order |
viewerInputOrder |
before viewer process |
Sets when the input process node specified is applied: • before viewer process. • after viewer process. |
|
enable monitor output |
MonitorOutEnable |
disabled |
When enabled, the Viewer is output to the connected monitor device. Note: You cannot enable this control if no monitor output device is specified. |
|
use video legal range |
MonitorOutLegalRange |
disabled |
When enabled, transform the monitor output to the legal video range. |
|
monitor output device |
MonitorOutDevice |
None |
Sets the monitor output device to receive the Viewer output: • None • Digital Cinema Desktop • Firewire |
|
monitor output mode |
MonitorOutMode |
- |
Sets the display mode for the specified monitor output device: • none - no selections are available. • D - select a Digital output device from the dropdown. • A - select a Firewire output device from the dropdown. |
|
monitor output pixel format |
MinorOutPixelFormat |
- |
Set the pixel format output for the specified monitor output device, dependent on the card's manufacturer. |
|
viewer selector mode |
viewerSelectorMode |
rectangle selection |
Sets the selection mode for the current Viewer: • rectangle selection • ellipse selection • lasso selection |
|
3D Tab |
|||
|
grid position xyz |
grid_origin |
0, 0, 0 |
Sets the position of the grid in the 3D Viewer on the x, y, and z axes. |
|
display |
display |
unchanged |
Adjust the display characteristics of 3D objects. These settings don’t affect the render output of the scene; these are for display purposes only in the 3D Viewer. • off - hides all 3D objects. • wireframe - displays only the outlines of object geometry. • solid - displays all object geometry with a solid color. • solid+lines - displays the geometry as solid color with individual object’s geometry outlines. • textured - displays only the surface texture of objects. • textured+lines - displays the wireframe plus the surface texture. • unchanged - doesn't change object display modes. Note: This setting can override individual object settings. |
|
transparency |
use_alpha |
enabled |
When enabled, objects appear transparent where their alpha is < 1. |
|
headlamp |
gl_lighting |
disabled |
When enabled, objects are shaded with a spotlight attached to the viewpoint to make their shape visible. |
|
alpha clipping |
gl_alpha_clip |
1 |
Sets the alpha value used by the transparency control which determines if an object is opaque or not. |
|
polygon offset |
gl_poly_offset |
1 |
Sets the visibility of lines in hidden-line mode. |
|
show |
show_points |
disabled |
When enabled, all points are displayed in the 3D Viewer. |
|
show_point_num |
disabled |
When enabled, all points are numbered in the 3D Viewer. |
|
|
show_point_info |
disabled |
When enabled, all points are labeled with xyz coordinates in the 3D Viewer. |
|
|
show_point_normals |
disabled |
When enabled, all available point normals are displayed in the 3D Viewer. |
|
|
show_point_uvs |
disabled |
When enabled, all available point uvs are displayed in the 3D Viewer. |
|
|
show_vertex_num |
disabled |
When enabled, all vertices are labeled in the 3D Viewer. |
|
|
show_vertex_normals |
disabled |
When enabled, all available vertex normals are displayed in the 3D Viewer. |
|
|
show_vertex_uvs |
disabled |
When enabled, all available vertex uvs are displayed in the 3D Viewer. |
|
|
show_prim_num |
disabled |
When enabled, all primitives are labeled in the 3D Viewer. |
|
|
show_prim_normals |
disabled |
When enabled, all primitive normals are labeled in the 3D Viewer. |
|
|
show_prim_bbox |
disabled |
When enabled, all primitive bounding boxes are labeled in the 3D Viewer. |
|
|
grid_display |
enabled |
When enabled, a grid displays in the 3D Viewer. |
|
|
default lens |
default_lens |
1 |
Sets the default lens (focal length divided by film width) to use in 3D mode when no camera is selected. |
|
near |
near |
0.1 |
Sets the limit of the OpenGL near clipping plane. Objects closer to the camera that this value are not rendered the 3D Viewer. |
|
far |
far |
1000 |
Sets the limit of the OpenGL far clipping plane. Objects farther away from the camera that this value are not rendered the 3D Viewer. The far clipping plane can be moved farther away if objects in the scene are farther away. In this case, the near plane is also moved so that the ratio between near and far planes is preserved. |
|
skew order |
skew_order |
XY |
Sets the order in which skew operations are applied. • XY - Skew on the X axis is applied before skew on the Y axis. • YX - Skew on the Y axis is applied before skew on the X axis. |
|
Soft Selection |
|||
|
Soft Select |
softSelect |
disabled |
When enabled, soft selection is applied to any selection made in the Viewer. When disabled, selections are made in the same way as legacy versions of Nuke. |
|
Falloff Radius |
softSelectRadius |
1 |
Controls the radius of the selection falloff added to the initial selection. Increasing the value includes selections from farther away from the initial points or faces. |
|
Falloff Curve |
softSelectActiveCurve |
S-shaped |
Sets the curve used to describe falloff farther away from the initial points or faces. |
|
curves |
softSelectCurves |
none |
Adjusts the preset curve selected in the left-hand panel. You can also add your own curve to control falloff using the + button. Adding a custom curve adds it to the Falloff Curve dropdown. |