How does Texture Coordinate's UV data contribute to specular calculation?
In the video, the object's UV map is sent to two Image Texture nodes, which are mixed in a MixRGB node, and then piped to a Color Ramp, which is then sent to Principal BSDF's specular input.
I realize that Texture Coordinate's outputs vector date, and Image Texture nodes outputs non-vector data, but how does Texture Coordinate's UV map information affect the resulting specular calculations when the Image Nodes are already using UV map images (namely treasure-chest_COLOR and DVC-bake)?
Also, what happens a RGB color output is connected to a Black and White input (such as the Color Ramp)? Are the values in the HSV data extracted from the Color data or are RGB values somehow mapped to greyscale for the Color Ramp to use?