Third Party Fuses/XfChroma Description

The following inputs appear on the tool's tile in the Flow Editor:

Input

Source image to be transformed. Required.

obvious :)

Like Fusion's transform tool, you can define scaling using a size and an aspect slider or separate x and y size sliders. Changes in one pair of sliders will affect the other pair. This behavior is different from Fusion's transform tool.

This slider allows you to scale down (or overshoot) all transformations at once. This way, you don't have to animate each property separately.

Defines the number of steps (+1 for the untransformed image) that will be rendered.

Define a gradient. By default, this is a color spectrum from pure red over pure green to pure blue. This gradient not only looks nice, it also makes the intermediate steps add up to the original image (see "Accumulation Mode" below).

Chose the color space that is used to interpolate between the gradient's colors. The default interpolation, HLS, looks a bit better when using the default spectrum.

If your input is in sRGB space (or you're not even sure what this is all about) you can set this slider to 2.2 to achieve more photorealistic highlights. In a linear gamma workflow, leave this at 1.

There are three different ways to merge the intermediate images. By default, they will get added. You can experiment with Screen and Max (aka Lighten) merge modes as well. Accumulation will internally be done in 32bit float, but the result will be converted to the input image's bit depth.
Merge mode (added in 1.4) is special. Instead of accumulation, the passes will be tinted according to the gradient and merged using a regular merge operation based on the input's alpha channel.

Only available in "Merge" mode. Defines the order in which the intermediate images are merged together. You can think of it as depth stacking: in "over" mode, later images will occlude earlier images. In "under" mode, each image is stacked behind the previous one.

Only available in "Add" mode and enabled by default. After all the intermediate steps have been added, each color channel will be normalized independently. This feature makes the images add up to the original image when no transformation is done and the default gradient is used. Leaving this option enabled with other gradients (e.g. a simple red to blue without green in the middle) may cause unintended color shifts. In this case, disable the checkbox, use the screen or max modes or tweak the "Reduce Gain" setting.

By accumulating multiple images (especially in "Add" mode) the resulting image will quickly exhibit a burned out look and have superbright values above 1.0 (if you're working in float16 or float32. Integer bit depths will get clipped). By reducing the gain of each image before it gets accumulated into the end result, you can work against this. This slider is not available when "Normalize Result" is enabled since it would have no effect.