Color: RGB Curves

Node Interface

Overview

Function	Alters colours by mapping the input level of each colour to a different output colour.
Nearest C4D equivalent	Filter shader, graduation curves section

This node is very similar to the graduation curves in the Cinema 4D Filter shader or the Curve dialog in Photoshop, if you use that. What it does is remap the colour input to a different output. For example, suppose a colour in the image is pure white, which will have a red component of 100%. The default curve will simply output the same colour. Now if you reduce the red curve so that it is always zero, the image will no longer have any red component and will be cyan instead.

You cannot edit the curves directly in the node. To edit the curve, select the node and then in the Node Settings tab of the right-hand pane of the node editor, select the channel to edit and you can then edit the curve. If you need a larger window (perhaps because you need to make some precise edits) double-click the curve you want to edit in the node, and a separate window will appear, which you can enlarge as much as required.

Settings

Note: a * symbol next to the name indicates the parameter also has an input port. A # symbol indicates that the parameter can only be changed with an input node, not in the node itself.

Channel drop-down menu

This lets you choose the channel to edit. RGB changes the overall colour while Red, Green and Blue change those channels respectively.

Curve

This is the curve for the selected channel. Note that you cannot edit the curve in the node. To edit it, go to the Node Settings and edit the curve there.

Fac *

The overall strength of the effect. A value of 0.0 means no effect at all; a value of 1.0 gives the maximum effect.

Color *

You can change the colour directly in this parameter, but you can input the colour from any other node which has a Color output. This is where you would link an Image Texture node to use a bitmap, for example.

Output

Color

The altered colour value.