Help understanding a shader

[caskal]

Hello community,

Some months ago I asked how to achieve this kind of effect 

 

Blackpixel user at sidefx forums did an awesome job with a mantra shader, at that time I was just learning the basics so I get stuck trying to understand, here is the post if someone wants to check out ( https://www.sidefx.com/forum/topic/44970/ )

I'm uploading the file that blackpixel did, all in mantra with shader builder, now that I learn the basics of shader builder I'm trying to really understand what he did, here are my thoughts:

 

So he take a worley noise (4 points) and split up to 5 fit ranges, one is set to the refraction, he multiplies 2 to get the displacement, then he does several multiply with colormix, is this to get the colours on the borders?

I tried to do it myself from scratch (attaching the hip too) with a similar but not the same result, I started adding one by one to see what is doing but I can't figure out yet.

My main cuestion is, from a designer point of view, lets say I want to create a shader that is black/milky (btw he isn't using SSS but it looks like), how should I think to say: this will be the plastic hole, this will be the border one, this will be the main surface, I guess he's doing all of that dividing the worley in fits right?, mantra is kinda scary yet so powerful.

Sorry for the long read

Cheers!

 

 

 

 

worley_holes_blackpixel.hip

worley_holes_caskal.hipnc

[caskal]

Nobody got a clue?

[trojanfoe]

Still there?  If you move those VOP nodes into a top-level Material Node (/mat for example) you should be able to drag each VOP node onto the render view and Houdini will create a temporary shader so you can visualize what each VOP does.  I am no shader expert, that's for sure, but each of those nodes does a single job and in order to understand you will have to experiment.

Edited April 28, 2017 by trojanfoe
Spelling.

[caskal]

On 2017-4-28 at 3:23 AM, trojanfoe said:

Still there?  If you move those VOP nodes into a top-level Material Node (/mat for example) you should be able to drag each VOP node onto the render view and Houdini will create a temporary shader so you can visualize what each VOP does.  I am no shader expert, that's for sure, but each of those nodes does a single job and in order to understand you will have to experiment.

Hey @trojanfoe thanks for the tip, that will make things much easier to understand, will give a try now, cheers!