Відео

Nuke software typically works with the alpha channel in different contexts like roto or keying. Here's what's happening based on your description: When you create a roto shape in Nuke, by default, it outputs a mask in the alpha channel. This is why the selected portion appears white; the shape is filling in the alpha channel to mark areas of opacity. If your viewer is set to view the alpha channel (pressing A), you'll see the selected portion in white and the rest in black. If you set the output of your roto to "None" instead of the default "Alpha," the roto will not generate any alpha information. This means that when you modify something like a luminance key, it applies to the entire image since there is no mask constraining the effect to a specific area. The alpha channel is crucial for isolating changes to certain parts of an image. Without it, any operation you apply (like color correction or keying) will affect the entire image. Make sure your roto node is set to output to the alpha channel so it can act as a mask when you make changes (e.g., using a luminance key). This way, the color change will be limited to the selected portion instead of the whole image.

Added in description

I can't understand your problem, will you please elaborate a little more.

Thanks