Author Topic: Physical material tutorial  (Read 1895 times)

2021-11-29, 16:55:54

jojorender

  • Active Users
  • **
  • Posts: 178
    • View Profile
Does anybody know a good YT tutorial explaining all the bells and whistles of the new physical material?
So far I avoided using the pbr mat but wanted to try the clear coat feature.
After looking at the help desk article. I have more questions than before.
Why does IOR get greyed out when in “metal” mode? Have I been setting up metal wrong for years?
What does the “Level” setting do in edge color?
Cleracoat: what’s the difference between “Amount” and “Roughness” (when to use what)?
…and so on.

Is it just me or would a dedicated “Normal” channel make sense for a new pbr material?
Most, if not all, tex generators output a normal map and adding the normal shader to the bump in every material by hand is a real time killer…

2021-11-29, 17:18:39
Reply #1

johnnyswedish

  • Active Users
  • **
  • Posts: 175
    • View Profile
I second that :-) Still a bit confuzed

2021-11-29, 18:26:04
Reply #2

CJRenders

  • Active Users
  • **
  • Posts: 80
    • View Profile
Is it just me or would a dedicated “Normal” channel make sense for a new pbr material?
Most, if not all, tex generators output a normal map and adding the normal shader to the bump in every material by hand is a real time killer…
[/quote]

Just use the BUMP layer in the base layer channel then under the arrow do >Corona>Normal

2021-12-03, 14:44:27
Reply #3

Nejc Kilar

  • Corona Team
  • Active Users
  • ****
  • Posts: 1080
    • View Profile
    • My personal website
Howdy! So we've been kind of hard at work getting a new series of tutorials out and... The first two videos are out today! The series is all about the Physical Material so hopefully they'll help answer most of your questions.

Check out the Cinema 4D version here -

Now because some of the tutorials are still in the making I'd like to try and answer some of your questions here as well.

Why does IOR get greyed out when in “metal” mode? Have I been setting up metal wrong for years?
IOR gets greyed out because metals aren't defined by a single IOR function to begin with - it isn't the wrong way to do it but it isn't quite physical either. It can be done more intuitively and that's what we tried to do with Physical Material.
Metals typically have a curve that is much more complex than the IOR curve. The biggest thing is what happens towards the edges, those grazing angles can even be of a different color and so with the new Physical Material you can use the "Edge color" parameter to define how that behaves - whenever you are using the Metal metalness mode that is. Now strictly speaking, the Edge color parameter is not a scientific way to define every metal - again, every metal has its own "reflection" curve. But, you know, it'll get you there better than that single IOR will. You can also use the Complex IOR feature inside the Physical Material but at that point you are basically splitting hairs - lots of effort for not a whole lot of a result.

What does the “Level” setting do in edge color?
It controls the strength of the reflections on those grazing angles on metals.

Cleracoat: what’s the difference between “Amount” and “Roughness” (when to use what)?
Amount basically defines the strength of it. It can visually also look like how thick that clearcoat is - full amount will look thicker, more reflective.
Roughness controls how rough the surface is on a micro level basically - same as with the base layer roughness just that it only affects that clearcoat only.

Hopefully these answers will be helpful for now. Do make sure to pay to attention to our Youtube channel for more tutorials that'll go more in depth into the new Physical Material :)

Nejc Kilar | chaos-corona.com
Educational Content Creator | contact us

2021-12-04, 01:35:47
Reply #4

jojorender

  • Active Users
  • **
  • Posts: 178
    • View Profile
Hi Nejc,
thanks for answering my questions and great timing on the tutorial!
I'll watch this weekend.
Still not really “clear” on the clearcoat, but I’m sure you’ll cover this.

2021-12-04, 20:09:00
Reply #5

ShahynRox

  • Active Users
  • **
  • Posts: 10
    • View Profile
I appreciate the new initiative for more tutorials as it is a still a desideratum for C4D users. But the “design” of the tutorials is not ideal. In my opinion the videos are far too long compared to the low amount of content. Too many repetitions and redundant information. I do not need to hear every 5 sec that the physical material is much smarter and much more realistic than the legacy material. If you do not explain WHY, it is enough to say that once and then bring relevant information how to use it. Try to condense the explanations to the real core information so that the videos are 5 minutes long. The first “tutorial” is 12 minutes long and has no info that is worth more than 2 or 3 minutes. The same with the second video (17 minutes!). You could communicate all relevant information in 5 minutes. The time saved could be used to produce more tutorials on other features of Corona for C4D.
I hope you do not misinterpret my critical review of the tutorials published so far. I really hope to see more videos! So thank you for the effort!

2021-12-05, 11:17:29
Reply #6

ianosss

  • Active Users
  • **
  • Posts: 60
    • View Profile
This is great thanks, I've wanted to know how to use the physical material properly so this tutorial series is much appreciated. When are the next ones coming out? (looking forward to seeing more). :)

I have watched a silly amount of tutorials over the years and I think these are pretty good. I understand what @ShahynRox is saying but think at this stage the introduction videos are fine. (I didn't personally find them too long and I have a short attention span) :)

I think the gold standard in my opioon for tutorials is MographPlus. The key for me is the videos are broken down into sections and are kept as short as possible so I can quickly find a specific section that I'd like to learn.

I was wondering if the youtube videos can be arranged differently so its easier to see if they are for 3DS Max or Cinema 4D? So for example having a separate youtube for Corona C4D/ 3DS Max or just separate playlists?


2021-12-06, 09:58:24
Reply #7

Nejc Kilar

  • Corona Team
  • Active Users
  • ****
  • Posts: 1080
    • View Profile
    • My personal website
I appreciate the new initiative for more tutorials as it is a still a desideratum for C4D users. But the “design” of the tutorials is not ideal. In my opinion the videos are far too long compared to the low amount of content. Too many repetitions and redundant information. I do not need to hear every 5 sec that the physical material is much smarter and much more realistic than the legacy material. If you do not explain WHY, it is enough to say that once and then bring relevant information how to use it. Try to condense the explanations to the real core information so that the videos are 5 minutes long. The first “tutorial” is 12 minutes long and has no info that is worth more than 2 or 3 minutes. The same with the second video (17 minutes!). You could communicate all relevant information in 5 minutes. The time saved could be used to produce more tutorials on other features of Corona for C4D.
I hope you do not misinterpret my critical review of the tutorials published so far. I really hope to see more videos! So thank you for the effort!

@jojorender
You are welcome! Yeah, the clearcoat tutorial is still on the way and I'm hoping it'll answer the rest of your questions. Clearcoat to me is one of those things that once you "get" how it works you really start to realize just how many things you can do with it.

@ShahynRox
Howdy! This comment definitely comes off as constructive criticism and we're happy to hear feedback like that, so thank you!

We'll keep that in mind for future tutorials and future series. That said, to give you a little background on why we've decided to make these longer rather than shorter... Well, this series is designed to be all about the basics - and we're hoping these will be a good starting point for novice users as well and so we've figured it's better to say more rather than say less.

There's more content planned besides this series so we plan on covering lots of different topics in the future. And as a tidbit of production info, the length of these doesn't really affect the time needed to get them out the door. Surprisingly so! :)

@ianosss
Thank you for your feedback as well! Appreciate the references and the kind words!
Nejc Kilar | chaos-corona.com
Educational Content Creator | contact us

2021-12-06, 15:44:26
Reply #8

davetwo

  • Active Users
  • **
  • Posts: 168
    • View Profile
I'm really glad that you're making these films. It's definitely needed!

To agree with ShahynRox some of the simple stuff can be moved over a bit quicker. Most users are not rank beginners.

The real need is to address some of the new ways of working - which to existing users are definitely not more intuitive.

Example below...  a simple bottle with greenish glass where it's thicker. Simple using the legacy material.
But the same settings give a completely different result in Physical. I have no idea how to set up my glass now - so just stick with legacy 99.9% of the time.

Can you enlighten me?


2021-12-06, 16:57:11
Reply #9

Nejc Kilar

  • Corona Team
  • Active Users
  • ****
  • Posts: 1080
    • View Profile
    • My personal website
I'm really glad that you're making these films. It's definitely needed!

To agree with ShahynRox some of the simple stuff can be moved over a bit quicker. Most users are not rank beginners.

The real need is to address some of the new ways of working - which to existing users are definitely not more intuitive.

Example below...  a simple bottle with greenish glass where it's thicker. Simple using the legacy material.
But the same settings give a completely different result in Physical. I have no idea how to set up my glass now - so just stick with legacy 99.9% of the time.

Can you enlighten me?

Thank you for the feedback, appreciate it!

For your particular example, I'm guessing you have the roughness set to a value quite a bit higher than 0% which is making the material ... Rougher.

We'll tackle this in the upcoming tutorials in the series but the roughness parameter affects both the roughness of your reflections as well as your refractions. So set that to match what you have set in the refraction channel in the legacy material and it should look similar. The physical MTL does use a different physical model for calculating refractions so values that aren't 100% glossy won't match 1:1, you'll probably want to tweak those slightly.
« Last Edit: 2021-12-06, 17:00:59 by Nejc Kilar »
Nejc Kilar | chaos-corona.com
Educational Content Creator | contact us

2021-12-06, 19:41:59
Reply #10

davetwo

  • Active Users
  • **
  • Posts: 168
    • View Profile
I'm really glad that you're making these films. It's definitely needed!

To agree with ShahynRox some of the simple stuff can be moved over a bit quicker. Most users are not rank beginners.

The real need is to address some of the new ways of working - which to existing users are definitely not more intuitive.

Example below...  a simple bottle with greenish glass where it's thicker. Simple using the legacy material.
But the same settings give a completely different result in Physical. I have no idea how to set up my glass now - so just stick with legacy 99.9% of the time.

Can you enlighten me?

Thank you for the feedback, appreciate it!

For your particular example, I'm guessing you have the roughness set to a value quite a bit higher than 0% which is making the material ... Rougher.

We'll tackle this in the upcoming tutorials in the series but the roughness parameter affects both the roughness of your reflections as well as your refractions. So set that to match what you have set in the refraction channel in the legacy material and it should look similar. The physical MTL does use a different physical model for calculating refractions so values that aren't 100% glossy won't match 1:1, you'll probably want to tweak those slightly.
.


Hmmm how strange. It wasn't the roughness setting, the glass was completely clear until I activated the volumetrics. Only then did it become cloudy. Thats why I found it so odd.

However, testing on another machine it does indeed work as expected! So it may have been some sort of bug. I deleted the old file unfortunately. But I'll flag if it happens again.



EDIT. Gah! My bad. I forgot that I'd plugged a noise into the glossiness slot of the legacy material. Of course when I copied it into the Physical material it was in the Roughness slot instead as that field has changed. So the noise had the opposite effect to what I was expecting.
« Last Edit: 2021-12-06, 20:25:35 by davetwo »