GeoGrade

The GeoGrade node allows you to make tonal adjustments to a prim or field, such as defining white and black points. This can be helpful in particular for Gaussian Splat workflows when working with fields and field meshes.

To sample pixels from the Viewer, click on a color swatch to the right of the control you want to set. The eye dropper icon appears. In the Viewer:

• Ctrl/Cmd+click to sample a single pixel from the node’s output.

• Ctrl/Cmd+Shift+drag to sample a region of pixels from the node’s output.

• Ctrl/Cmd+Alt+click to sample a single pixel from the node’s input while viewing its output.

• Ctrl/Cmd+Alt+Shift+drag to sample a region of pixels from the node’s input while viewing its output.

• Ctrl/Cmd+ right-click cancels pixel selections.

Note: This is a LABS node, indicated in Nuke with the tag:
LABS nodes are experimental and not intended to be used for production.

Inputs and Controls

Connection Type	Connection Name	Function
Input	mask	The prim or field you want to apply the grading to.
	B	An input for connecting other nodes in the scene.

Control (UI)	Knob (Scripting)	Default Value	Function
GeoGrade Tab
Mask	mask_patterns	Default - Injected/ All Roots	Specifies the mask pattern, for targeting the prim(s) to affect. You can use standard glob-style wildcards, such as '', '?', to create masks or use individual prim names separated by spaces. For example, /GeoCube1 /GeoCard3 applies the effect to only those prims. Default - Injected/All Roots* - selects the default prim(s) for the node. The default will be the injected mask prim paths if there is an upstream node with this. Otherwise the default mask for this node type is evaluated. All roots - select the top level Xform(s) in your scene. Last modified - selects whatever the last node modified was. All Cameras - selects all Cameras in your scene graph. All Lights - select all lights in your scene graph. All Meshes - selects all meshes in your scene graph. Custom - sets a custom selection of prims that exist in your scene graph. Tip: You can also use the cog menu, the Viewer picker, or drag and drop paths from the Scene Graph to create masks.
Inject Mask	inject_mask	off	When enabled the mask in this node is injected into the node directly below it if that node has the default path mask set.
Black Point	blackpoint	0	Sets the black point (typically the darkest pixel). Any pixels of this value are set to 0. In other words, this color is turned into pure black. Typically, you would set this by sampling the darkest pixels in the Viewer. To find these in your image, you may want to temporarily increase the gain in the Viewer controls until only the darkest pixels are visible. Adjusting the Viewer gain does not affect the colors you sample.
White Point	whitepoint	1	Sets the white point (typically the lightest pixel). Any pixels of this value are set to 1. In other words, this color is turned into pure white. Typically, you would set this by sampling the brightest pixels in the Viewer. To find these in your image, you may want to temporarily lower the gamma in the Viewer controls until only the brightest pixels are visible. Adjusting the Viewer gamma does not affect the colors you sample.
Lift	lift	0	Any pixels that are black are set to this color. This allows you to, for example, match the tonal range of one clip with that of another. First, set Black Point to the darkest pixel in the image whose colors you want to change (pressing Alt to make sure you sample from the input). Then, set this control to the darkest pixel in the image whose tonal range you want to match (not pressing Alt to make sure you sample from the output).
Gain	gain	1	Any pixels that are white are set to this color. This allows you to, for example, match the tonal range of one clip with that of another. First, set White Point to the lightest pixel in the image whose colors you want to change (pressing Alt to make sure you sample from the input). Then, set this control to the lightest pixel in the image whose tonal range you want to match (not pressing Alt to make sure you sample from the output).
Multiply	multiply	1	Multiplies the result of the GeoGrade node by this factor. This has the effect of lightening the result while preserving the black point.
Offset	offset	0	Offsets the result of the GeoGrade node. Offsetting is to add a fixed value to the result, which, in effect lightens the whole image. You can also add a negative value to the result, in which case the whole image gets darker.
Gamma	gamma	1	Applies a constant gamma value to the result of the GeoGrade node. This lightens or darkens the midtones.