The Gradient texture produces a gradient blend between colors. It accepts an input to determine how the gradient is mapped to the surface. This last sentence is important because this node works differently from the gradient style than the classic gradient style. In Octane gradient, any 2 colors will mix with each other if you do not use the input channel. Just like in the mix shader or cosine mix. To understand how this node works, you can refer to the following example usage.
HOW TO USE (IN SIMPLE MODE)
Gradient texture works in 2 modes. Simple and Complex. Let's first explain how simple mode works by looking at the following usage examples:
Coloring any greyscale procedural texture using gradient
In simple mode, we'll say "value" for each color you assign to the gradient. This value can be any color or image texture. In simple mode you can define a maximum of 2 values, and any color or image texture will be mixed according to the data you define in the input node.
As you can see in the Node setup below, the greyscale checker is used as texture input and the colors are changed by entering two separate values (ie, color) in the gradient.
RE-Coloring ANY Image texture using gradient
If you simply want to change the colors of the image texture you uploaded, you can also use Gradient. The following setup shows this process.
using gradient to get a classIc gradIent look
As you can see, the Gradient name may have misled you. While you were expecting a classical gradient function, the Octane gradient actually appeared as a much more powerful tool. But still, if you are asking "How do I make the classic gradient?", the following setup will help you. You can also use native Cinema 4D's "Gradient" for the classic look of any gradient blends.
using gradient as a mask functIon for dIrt (or ANY OTHER PROCEDURAL TEXTURES)
You can also use the Gradient Node as a mask. The default values, black and white (or float values which is 0 and 1), can use as a masking functions. In the following setup the "Dirt Texture" is assigned to the Dragon Object and then using the gradient to make this dirt appear only in the crevices. You can easily use this method in many places and scenarios.
HOW TO USE (IN complex MODE)
Gradient texture shows its power in complex mode. Instead of 2 values in Simple Mode, you can use many value values in this mode and also it's possible to use any image or procedural texture for each of them. Also there is no 2 texture limit in this mode like in the "Mix Texture". To switch to complex mode, first select "Mode / Complex" from the gradient option and then go to the gradient menu. Now, every color you enter from the color section is "value". In this case you can add "knots" to gradient colors according to the complexity of the material. The following setup is a simple setup. Only 1 "value" is used except the "Start and End" values to get the texture in the picture. Also one image texture used as a input texture and mix factor. As you practice, you will understand much better how gradient works. You can download and examine the sample scene from the link below.
Download the scene from this link
From here you can select the gradient mode. There are 2 modes: Simple and Complex. Both are explained above.
lInear and radIal optIons
You can select the gradient style from here.
Select from Constant, Linear or Cubic to determine the rate at which colors blend from one gradient knot to the next.
Input to determine the way the color is mapped to the surface. The importance of this option is explained in the examples above. For an accurate mix, you can define RGB / Alpha / Greyscale procedural or image texture here.
Makes the mix style smooth.
From here you can add "value" or knots according to your chosen gradient mode. In Simple Mode, only the start and end values are work; if you want to add a third or more knot you need to change the Complex mode for this.