For the Marble Texture in the beginning, why do we mix the mapping node with the Noise Texture using the linear light mix color node before connecting that output into the voronoi texture?
Hi Jim,
The Noise Texture Outputs Values between 0 and 1, with an average of 0.5.
Linear Light something with 0.5 changes nothing, meaning it Outputs the something you Input (in A).
You could also (Vector Math) Subtract 0.5 from the Noise Texture and then Add or Multiply the result of that with the Output of the Mapping Node.
The result would be different, but it would still change the Mapped Vector in all directions equally, instead of in 1 direction.
This explanation will probably not help you much, but play with it and see what happens. At some point, the coin will drop.
Well, I guess I just want to know what this is for, is it basically to add noise to the the mapping coordinates, making the voronoi texture mapping more warped?
Also another question, why do we use the output of the color ramp which maps the veins of the marble into the factor input of the mix color node?
"why do we use the output of the color ramp which maps the veins of the marble into the factor input of the mix color node?"
That Output gives mostly black (zero, Input A), meaning the Mix Node Outputs 'green'.
Where the Color Ramp Outputs white (one, Input B), the Mix will Output 'gold' for the veins.
Consider each Node in a Node Tree (from left to right, in Shaders) and look at what goes in and what comes out, when what goes in, goes in.
It takes some getting used to and also, you need to know what the Node does.
But you are not alone; everybody struggles with this at the beginning. Some never learn. And some of those still are great artists, so there is nothing to worry about.
There's lots of technicalities when it comes to using nodes, but if you ask me, almost everyone, like 95% of people just goes at it by feel. You see people doing stuff on tutorials and you imitate it, you remember you saw someone doing this trick and you emulate it, you start getting a feel of what you want in your material and you add a node here and there and before you know it, you have a noodle that makes you look super professional. All that talk to say, don't worry too much if you think you're not getting it all, like you should know what every single setting does, because truth is, you get the feel of it all up to a point, after that is just a lot of adding stuff to see what it does. As you see more and more material building you'll start to get the feel. I remember Andrew Price saying after 10 years of using Blender, he finally understood the Color Ramp node, and the guy pumps out art in spite of it. That's what I mean, that the technical is not as impacting as we set out to believe.