Modifying Gradient Channels

Modo allows you to dynamically generate and modify gradients, rig their values and vary them over time. They enable you to carry out simple tasks, such as generating a new gradient from a waveform, as well as complex ones, like introducing noise or offsetting the value of a gradient.

Gradient Modifiers and Gradient Layers

Depending on whether you want to generate a new gradient from source gradients, or apply an effect on an existing gradient, you can use Gradient Modifiers or Gradient Layers.

You can use Gradient Modifiers to read an incoming gradient, perform an operation on them and output a new gradient. They allow you to blend gradients, generate a gradient from a mesh layer, perform mathematical operations on gradients, and so on. For more information, see Gradient Modifiers.

Similarly to Gradient Modifiers, Gradient Layers allow you to modify a gradient. However, instead of using a series of channel links to compute a new gradient, you can modify a gradient channel in place, by evaluating a stack of layers from the bottom up to modify the gradient curve. It works similarly to the Mesh Operations list and the Shader Tree. The base gradient is evaluated, and the value is passed up the stack to be modified by subsequent layers, until the final computed value is output from the channel. Gradient Layers can be added to a gradient channel using the Gradient Layers viewport.

Accessing the Gradient Layers Viewport

To open the Gradient Layers viewport you can add a new Data List tab to the right panel, or open a new window.

To open a tab on the upper or lower right panel, click the + sign to the right of the tab names, and in the dropdown, click Data Lists > Gradient Layers.

Note: If your right panel is narrow, a triangle is displayed instead of a + sign. In that case, click the triangle, and in the dropdown, click New Tab > Data Lists > Gradient Layers.

To open the Gradient Layers viewport in a new window:

In the menu bar, click Layout > Windows > New Window > Data Lists.

This opens a new window.

Click the triangle in the top right corner and select Data Lists > Gradient Layers.

This opens the Gradient Layers viewport.

Using Gradient Layers

Select a Gradient channel you want to modify. In the following example, we have a Polygon Bevel applied to a plane, modulated by a Radial Falloff. We're using the Radial Falloff's Gradient channel.

You can double-click the Gradient channel on the node to open it in the Gradient Editor:

In the Gradient Layers viewport, click Add Layer and select the Gradient Layer you want to use, for example, Noise.

Note: For more information on the different gradient layers, see Gradient Layer Types.

Your source gradient is modified by the new layer.

To edit the Gradient Layer's properties, select it in the stack and open the Properties panel on the lower right. Adjust the properties as needed.

The result of the Noise layer applied with the Amplitude set to 7.0 looks like this:

Adding multiple layers on top of each other and reordering them by dragging them around in the viewport allows you to produce a wide range of effects.

To hide a layer, toggle the Visibility button on the left. To delete a layer, select it and press Delete on the keyboard.

Gradient Layer Types

The following Gradient Layers are available.

Clamp

Gradient Clamp clamps the gradient output value, ensuring that the value never exceeds the specified minimum and maximum range. You can edit the minimum and maximum values in the Gradient Layer's properties.

Gradient Clamp Layer Properties

Minimum Value	The lower end of the clamped range.
Maximum Value	The upper end of the clamped range.

Noise

The Noise layer applies Perlin Noise to an existing gradient. You can control both noise amplitude and frequency in the layer's properties.

Gradient Noise Layer Properties

Frequency	Determines how regularly the noise occurs per second.
Amplitude	Controls how strong the noise offsets the original base gradient.
Seed	Seeds the randomness of the noise generator. Animating this value animates the noise.

Offset

The Offset layer offsets all the values in a gradient equally, either by offsetting the value in Y, and/or the time the value is sampled in X.

Gradient Offset Layer Properties

Offset X	Offsets the gradient value in X. This offsets the sample time, so reading the gradient at a specific time sample remaps the time sample to read the input gradient at a different time.
Offset Y	Remaps the gradient value, adding the Offset Y value to the input gradient sampled value.

Scale

The Scale layer can be used to scale a gradient either in the Y axis, modifying the gradient's value, or the X axis, modifying the time of each value. You can also control the pivot point for each axis the scaling is performed in.

Gradient Scale Layer Properties

Amount X/Y	The amount the input gradient is scaled in the X/Y axis. Changing X modifies the sample time of each value in the gradient. Changing Y increases or decreases the gradient values.
Center X/Y	The pivot point to perform the scale in the X/Y axis. The gradient is scaled from this position.

Step

The Step layer rounds values in a floating point gradient to their nearest whole number. For example, 0.25 becomes 0.0, and 0.6 becomes 1.0. This can introduce a step pattern to gradients that cover a large range of floating point values.

Waveform

The Waveform layer generates a gradient from four standard waveform presets: Sine, Square, Triangle, and Sawtooth. You can use this to create regular repeated gradients.

Gradient Waveform Layer Properties

Type

The type of waveform to generate:

	A sinusoidal waveform that describes a smooth periodic oscillation from one extreme of the amplitude to the other.
	A square wavefrom that rounds to the nearest amplitude value.
	A triangle waveform that blends in linearly from one extreme of the amplitude to the other.
	A sawtooth waveform that blends linearly to the positive extreme of the amplitude, and then snaps back to the negative extreme of the amplitude.

Amplitude

The highest and lowest peak of the waveform. A value of 1.0 produces a low of -1.0, and a high of 1.0.

Frequency

Determines how regularly the oscillating motion occurs per second. A value of 1.0 produces one up and down cycle per 1.0 time step.

Offset

Offsets the gradient output value in the Y axis.