Iray DS Base Shaders

[Pendraia]

Sounds good Szark...even just going through what the different options are in the surface tab would be worthwhile. I look at some of them and haven't a clue what they do.
I did find this recently and they have just released one on Iray to do with environments.

 

[phdubrov]

I had had to read Iray Uber Base to understand what is what and why. (Not to have some ideas but to know what is what and how it works.)
DazStudio4\shaders\iray\daz_3d\... + book on MDL.

 

[Pendraia]

Do you mean looking at the mdl file in note pad type editor?

 

[phdubrov]

Yes.

 

[Pendraia]

Hmm...that looks very complicated.

 

[phdubrov]

Bulky — yes, complicated — no. But I'm coder, so it's just another (rather simple) language for me. But yes, it's 2.5k loc because it's Uber Base. And that's why I like specialized shaders.
(For comfort looking through it you may need editor with line numbers and ability to split workspace.)

 

[Szark]

No I will be sticking with the base presets as I am not a coder and many users are not either. All my images are done with the Metalicity/Roughness shader as it is the easiest to learn IMHO. Plus it seems to be the new standard for PBR, though some use the Spec/Gloss mode still.

 

[Pendraia]

I find reading through code frustrating at times...I think I would learn more playing with the different blocks in Shader Mixer. I'm very visual at times...

The Uber Shader base is like spaghetti when you look at the nodes. Not sure how much of it is actually needed for every shader. I think it's set up that way to allow more options once it's been applied to something. It would be interesting to try building some basic networks for Iray and seeing what can be done with it. My biggest problem is lack of time...

 

[phdubrov]

Not sure how much of it is actually needed for every shader.

No more than third IMO for very complicated materials, say cloth with metals and gemstones done with one mat. (But good thing is you can do it.) It's the price of Uber-shader — one to rule them all.
Edit - sorry. I was talking about code. Almost all bricks is needed - bigger part of them is texture coordinates setup and bump/normal/displacement setup.

It would be interesting to try building some basic networks for Iray and seeing what can be done with it

I started with recreation examples from MDL handbook in ShaderMixer to have visual experience. Then I began to play with Nvidia examples to see how it done. And then Ubershader.

 

[Szark]

I do envy people that can code. I just don't have the brain for it...yes I have tried and even took a course once. I asked the teacher ok what does this and that mean translated in to English and he said there wasn't. SO I asked how can learn if I don't why I am entering this and that command., it must mean something. He couldn't answer my questions so I left.

 

[Pendraia]

I had a maths teacher in form 4 like that. Totally lost interest when she couldn't explain why an equation worked. I loved math when I did my teaching degree. For the first time someone explained why pye works and is the number it is...

 

[Szark]

Oh teachers that fail us...story of my life. That is why I teach myself when I can.

Pye...hum a non whole number to describe the area of a finite surface...are we sure it is right. LOL

 

[Pendraia]

Yep and you can check it. Let's see if I can remember this...it's been a while. If you measure the diameter it will be approx 3.14 times that length which is the circumference this is easy to check using a piece of string and placing small pegs to represent the diameter length. We actually used concrete materials to prove this when I was at uni...and it's how in Australia we teach maths we try to get students to work out the logical patterns using materials. For example if you're doing skip counting you ask students to look for the patterns. An example of this is counting by 5's from zero will always be 0,5 in the ones column. If you change the starting point it will then develop a new pattern for example starting from 4 will by 4, 9. Most grade 2's are really good at picking up patterns like that and also the patterns in a 100's chart.

 

[Szark]

lol but the problem is pye is commonly approximated as 3.14159 occurring. I never got that how an approximated number could be used to define a fixed area. This was a question I asked my maths teacher at 11 and was told to sit down a shut up.

 

[Pendraia]

That's why its approximate...I always wonder who was fixated enough to sit there and work it out by measuring all the different diameters so they could prove it!

 

[Szark]

LOL many people I would guess.

 

[phdubrov]

Some names here Pi - Wikipedia, the free encyclopedia
And C/d=const can be prooved without measurement, but you needs limits at least IIRC from school.
But I just don't get meaning of "how an approximated number could be used to define a fixed area".

 

[Szark]

a plane has finite size and the area is a finite exact measurement. However we use an approximated Pye value for a circle, which doesn't give a 100% finite measurement but a close approximate but in reality to circle has an exact and precise area.

 

[phdubrov]

Seems like mostly definitions/assumptions question to me:
A. In reality all is approximated (have measurment error), including Euclidian space as approximation.
B. In common abstract assumptions (Euclidian space and real numbers - as opposed to rational numbers) circle with exact area should have irrational diameter. So you can't 'draw' such a circle.

 

[Pendraia]

Okay...you just went right over my head with that one.