Notch Reference Manual

FFT Blur / Glow

Method

This node performs a blur operation in frequency space using a Fast Fourier Ttransform (FFT). This allows any size of blur to take the same amount of processing time – even for huge blur kernels – at the cost of the conversion of the image into frequency space and back, which is constant for a given size of image. This makes this process useful for performing very large blurs much more efficiently than using an iterative blur with the Blur node.

Raw texture Processed texture
Example Nodegraph

Attributes

Name Description
Active Enables or disables the effect. Disabling the effect means it will no longer compute, so disabling a node when not in use can improve performance.
Blend Amount Changes the opacity of the new effect over the original image.
Blend Mode (RGB) Change how the generated effect blends with the parent image RGB.
Blend Mode (Alpha) Change how the generated effect blends with the parent image alpha.
Blur Shape Texture Shape the blur based on a texture.
Downsample Iterations Number of times the image is downsampled
Blur Size The size of the blur.
Threshold The luminance threshold at which a pixel will contribute to the effect.

Affect Channels

Select which of the RGBA colour channels are affected by the effect.

Inputs

Name Description Typical Node Input
Active Enables or disables the effect. Disabling the effect means it will no longer compute, so disabling a node when not in use can improve performance. Envelope Modifier

Outputs

There are no outputs from this node.