This location is for Registered Users Only.
Perhaps you need to login or register.
11.0, 10.5, 10.0, 9.0 or later
The first additional option is 'Enable Lin>Log preprocess'. This checkbox activates and deactivates a Lig2Log node that expands the mid tones range which can help (in some situations) to key a certain element better.
When selecting 'Luminance Key' operation, a checkbox and some sliders appear. The checkbox allows creating a custom luminance algorithm defining how much influence do R, G and B channels have in the luminance. The sum of the three amounts must be 1. I have tried to force the node to help users to achieve that result automatically, but as I'm a Python beginner user, the code is not perfect. Sometimes it can be possible to channel amounts to achieve negative values. Don't worry, the error is usually really small and I have placed clamp nodes to prevent negative and over 1 values getting into the equation.
Chrominance operation lets you sample a color from the image. That color's RGB values are mapped to 0,0,0 XYZ values and a matte image is generated calculating the distance in 3d space between the sampled values and the rest of the pixels.
As soon as you select Difference Key another input appears in the gizmo. You can connect your cleanplate to in or just a solid color and a matte of the difference between both of them will be created.
The last operation is Bump Keyer. It is useful to generate a matte of the bump details of the image. 'Blur size' is a kind of threshold to decide what should the keyer consider as bump detail. 'Bum Subtraction' helps to define better that detail. 'Alternative Method' sometimes can provide a better result.
Finally, you can clamp the output alpha using the 'Clamp alpha' checkbox.
I hope you find this gizmo useful. I would really appreciate if you could spend some minutes giving me feedback about it :)